(Co-)curating the rural traditions and material culture of villages: a case study in Wanju, Korea

Writer : Seong-mi Jeong
Year : 2019


ABSTRACT


This study discusses the need to preserve and protect the value of material culture related to the rural lives of the villagers of the Wanju area in the south-eastern part of Korea. It starts with the following questions. Does the museum and cultural property protection policy in Korea actually protect cultural resources? What about the marginalised cultures of rural villages and their material culture? Will they all disappear? And because these cultural resources are relatively modern, are we neglecting their safeguarding because they are not old enough?  In this article, I examine the current status and characteristics of material culture that have been found through studies of residents living in the rural villages of the Wanju area, and consider how they acquire value as heritage. In particular, I seek to find a connection between tangible and intangible cultural heritage through links between various cultural resources. Fieldwork and interviews with the villagers enable them to uncover the history of villages and their residents, and to curate their own experiences and settings, an important way to facilitate an integrated approach to identifying material culture in rural areas and rescuing these undervalued cultural resources.



Introduction

This study discusses the preservation and protection of the value of living heritage found in rural villages. In the past, some researchers of rural society have studied this culture by focusing on ways of living or patterns of behaviour transmitted from the older generation (Jae-yul Choi:  1986). Others have seen it as a result of accommodation to the natural environment of surrounding areas which includes economy, lifestyle, speech patterns, ways of thinking and values, historical artefacts and historical sites (Sang-bong Im, Hwa-gyeong Kim: 2006). Although both characterisations are centred on culture, previous studies tended to emphasise the cultural totality, abstract pattern, and remoteness in history of rural society. However, I decided to investigate rural culture from the perspective that living heritage, comprising material and non-material cultures, provides concrete, diverse and rich evidence of rural culture.

Therefore, cultural resources are here defined as material and non-material data relating to people's lifestyles. The institutional protection systems in Korea do not recognise these as belonging to the category of folk cultural properties so they cannot be registered as such because they do not meet the necessary criteria, such as scarcity, artistry, or acknowledgement by academia. However, these cultural resources show us how times have changed since the era of Japanese colonial rule and liberation in the late Joseon period.

At present, the villages’ living heritage formed of rural traditions and material culture is only recognised as a resource for local development through tourism promotion, exhibitions and so on. However, the value of rural traditions and material culture is more important than ever. There is great interest in preserving and exhibiting these in museums of various types. One of the factors that triggered a change in the perception of the values and importance of living heritage is the new cultural property policy of central government and the municipalities.

The recognition of cultural resources has extended from the traditional to the modern, and the range of items deemed worthy of preservation has expanded from the property of famous people to those items owned by ordinary people. A typical example is the registered cultural property system of the Cultural Heritage Administration, which was created to preserve modern cultural resources and future heritage systems designated by several municipalities.

At the same time, various national and private museums are expanding their activities to identify and value the heritage of recent times, and are introducing material culture from the country and the regions to ordinary citizens. Museums can conduct research which deals with general subjects including the humanities, society, culture and the arts, and human values. Cultural resources are not handled in any one type of museum. As of January 2018, there are 873 museums in Korea, 225 of which have exhibited artefacts related to material culture. They range from folk museums, history museums, agricultural museums and museums of daily life, to university museums, eco-museums, and museums of women’s history.

There are differences in the degree to which value is ascribed to material culture in museums, in how collections are interpreted and in how exhibitions are conceptualised, designed and developed. However, a lack of fieldwork in preparing content for exhibitions is becoming an unfortunate trend. There is also a lot of interest in purchasing artefacts from dealers who acquire items without recording the details of their history and provenance. This study therefore starts with the following questions. Does the museum and cultural property protection policy actually protect living cultural assets and cultural resources? What about the marginalised cultures of the rural villages and their material culture? Will they all disappear? And because these cultural materials are relatively modern, are we neglecting their preservation because we don’t regard them as old enough?

Ultimately, these questions are linked to the challenge of recognising the importance of the living heritage of farming villages. In this article, I examine the current status and characteristics of living heritage that has been identified through surveys of residents in rural areas.  In particular, I seek to re-create the connection between tangible and intangible heritage by finding links between various types of cultural resources.



The status of living heritage in rural villages

The project team of which the researcher was a member, carried out a survey of 170 villages between September 2018 and January 2019 in six towns in Wanju-gun County: Unjeong-myeon, Hwasan-myeon, Gyeongcheon-myeon, Bibong-myeon, Gosan-myeon, and Dongsang-myeon.  Wanju-gun County is a mountainous area with a relatively small amount of cultivable land; its main agricultural products are rice, beans and barley.

The six areas studied belong to the mountainous part of Wanju-gun County, and produce persimmon, jujube, chestnut and soybean. The research started with us contacting the heads of the villages where the survey was to be conducted. Cultural materials were then collected during interviews with the residents. Researchers visited the homes of those villagers who had been recommended to them and carried out field investigations. In the process, we learned that there are people in the villages still using old items alongside modern ones. Most of the residents are very elderly, so we can confirm that this material culture is in imminent danger of disappearing from use.

We followed certain procedures to investigate, record, and preserve selected artefacts. First, we tried to gather basic information about the item: location, the name and address of the owner and manager, etc.. Secondly, we created data fields to describe the artefacts - type, name, quantity, manufacturer, date, use, material, structure, and form of the materials. Thirdly, we processed the data – recording the process of an artefact’s creation, its state of repair, preservation status and historical background. We considered the meaning of the objects in the life of their owners and how that meaning may have changed over time.

Various kinds of farm equipment and household utensils produced or kept in villages by individual residents or village units were documented, and many of the artefacts are similar. The case of a 'knife for dried persimmon', for example, is related to the unique activity of a specific region. The area is known for producing the bulk of Korean dried persimmon. This type of knife, or gotgamkal , is a tool used to cut off the hardened ends of the fruit and to peel the persimmon. The handle is made of wood, and the blade is often cut from the end of a sickle, and the knives are usually made by the blacksmith, or at home by villagers.

The sizes and shapes of the blades vary according to the size of the persimmons produced in the area. Duri persimmons are native to the village we surveyed, so the knife blades had to be small enough to deal with them (Plate 1).

Information about the buildings used for the traditional process of storing ginger and about the iron sheds used for animals is also significant because these buildings no longer exist. The ginger storage buildings were built to store ginger for several months, and it had to be kept at a temperature below 15 degrees. In the village we studied the ginger storage house was called a xiangul . Most village houses used to be heated by the on-dol method in which heat is conveyed upwards from the lower part of the house, so many villagers dug under their own floors to store ginger, sweet potatoes and radishes. Nowadays the building of mechanical low temperature warehouses has caused these practices to all but disappear, but there are still a few houses that have ginger stores.

Other aspects of living heritage are related to women's work, such as the dotu-mari and badi(traditional weaving tools), spinning wheels, sewing machines, laundry bats, brass drums, millstones, brass irons, mortars and various kitchen utensils, as well as hemp, ramie and silk clothing. Data related to wedding ceremonies such as gifts, honseoji (wedding vows) and sajudanja (a ceremonial document recording details of the bridegroom’s birth - hour, date, month and year) were also discovered. These artefacts are not only related to gender, but they also demonstrate the differences in the class or wealth of families. Some poorer informants said that they did not bring anything when they got married, or that they only brought a few sanitary items, while there were others from wealthy families who made long bridal lists. Under Confucianism, this was a formality which all honourable families had to follow.

Several elderly women had still kept their wedding clothes and wedding vows very carefully. The honseoji (wedding vow) took the form of a letter sent from the groom's house to the bride's home. The wedding vow pictured was written by Jae-deok Kim (Gwangsan Kim), the father of Myeong-hyeon Kim, and it was sent to Goheung Yu's house on October 28, 1959 (Plate 2). The following is a summary of the contents:

It is a very cold season. Hope all is well. Please excuse my eldest son, Myeong-hyeon Lee who has already grown up, but has yet to come into his full potential. It is the honour of my family to have your precious daughter a friend of my child. Therefore, I will do my best in all my heart, that the ritual between the two will be blessed. [my translation]
For centuries, brides have stored their wedding vows in a chest and cherished them for the rest of their lives. Their final step was to put their wedding bow on top of their wedding ritual box. Yeong-sun Yu (80 years old) of Seokjang village still cherishes the wedding vow written by her father-in-law, and kept for the last 60 years in the same chest. Collections of prizes, such as the Grand Prize for women issued by the Saemaul Undong (New Community Movement) office were also found. The Saemaul Undong movement in rural areas emphasised the importance of the roles of the village leader and the president of the women's association. In the 1970s, village leaders played an important role in managing the ‘family registration’ of the village. From 1983 to 1987, the Saemaul Farm Journal , an almanac written by the leaders, was used to accurately describe the temperature, weather, and the rainfall of each day. The record shows, for example, that the Bibong-myeon area has been engaged in watermelon farming since the 1980s when this crop became popular. Various types of greenhouses were also introduced at this time. Musical instruments ( Jing, Kkoengwari, Janggu, Sogo etc.), funeral money collecting boxes and yoryeong, yeonja banga , and muk-ju (items related to religious practices) were also discovered. A yo-ryeong , a bell which makes a high-pitched noise when shaken, was used by the village community to mourn the dead ( sangyeo-bangwul ), but is rarely used now.

An exceptionally long rosary (240cms) was also found. A sacred object, comprising a string of beads with a cross dangling from one end, was used by Catholics when praying, enabling the user to keep count of the number of times they repeat their prayers. The rosary was used not only within the family, but also when the inhabitants of the village gathered together to pray. Catholicism came to the Korean Peninsula in the late Joseon Dynasty, and arrived in the villages around 1839 after the persecution of Gihae , as many worshippers from Chungcheong province settled there.

Finally, there are artefacts left over from the war in rural villages, such as grenade rings, land mines, rain jacket string and stores of ammunition. There is a flagpole in the village of Yongbok, built by Gi-soon Lee (89 years old) 5 years ago, using parts taken from grenades. He still proudly flies the South Korean flag on this flagpole. Gi-soon Lee took part in the Korean War and fought in many battles in Wanju-gun county and because of his wartime experiences he has many items from that time. The memory of the war in the village is an important part of his identity.

The abundance of living heritage that can be found in the villages shows how agriculture has changed in rural areas due to modernisation, filial piety, rural leadership and the Saemaul movement, as well as to changes in the village community and its lifestyle.  It is therefore necessary to analyse why these cultural materials still remain in these houses as they do.



Finding values through the curatorship of villagers

The villagers have their own stories about the times through which they have lived. Their relationships with their parents, their spouses, their children and their neighbours create unique personal stories, and because they are genuine stories, it is critically important to record and preserve them.  The use of cultural heritage should be preceded by rigorous research into the experiences and memories of the individual holders of specific artefacts, so that the saying, to re-discover the value of cultural heritage is to find new value in it becomes true (Plate 3).

The profound truth about many aspects of living heritage is that most of it is short-lived or lost due to rapid social change.  Since the 2000s, there has been a sudden rise in the number of modern houses being built in rural areas, and as a result there are many cases of artefacts being thrown away or sold off to junkyards and dealers. Even where artefacts survive, it is nearly impossible to know the full story of an item without speaking to the original owner. In order to appreciate the cultural values of these artefacts, it is pertinent to exhibit them, while rigorously researching the entire life of the village. In addition, it is also important that village residents come to realise the value of their own collections through this process.

Whenever a survey was conducted at a house that contained such artefacts, a list was made of the materials left in the house. The location of the artefacts in rooms, on floors, in kitchens, warehouses, and so on was also documented, as was the use of tools whether for agriculture, food preparation and shelter, or for ceremonial artefacts and their significance. The research captured a picture of life in that particular home, and recorded the history of the occupants, including how things differed for a woman before and after her marriage, or before and after the remodelling of the house, and of who was part of the household - parents, siblings and so on.

This survey method provided an interview environment which resonated with informants’ memories about their objects, enabling them to give informed responses to basic questions and revealing specific details about them, like how they were acquired and how they were used in the recent past. In addition, the informant’s appreciation, thoughts or opinions of the artefact was important, often revealing new facts about the owner, family members or other villagers.

Enabling the villagers to curate their own history allowed us to examine items and identify what they represented in terms of traditional knowledge and practice. For example, the jak-du , was a tool used by Bang-rye Kwon (84 years old) to chop up ‘rice straw’ in order to feed the cows or build clay walls (Plate 4). Cattle-raising was common just 20 years ago - people who spent their childhoods in rural areas will remember cows pulling carriages or ploughing rice paddies. But as cattle-raising disappeared, so too did the jak-du . These days, cows are fed with long rice straw, but in the past, people cut the straw into shorter lengths using the jakdu because it was more convenient to boil up shortened straws with food waste. There are various reasons for the change. Firstly, cattle are less important today as ploughing and harrowing have become mechanised. Secondly, the practice of keeping cattle in or near the house was dirty and smelly and has become less acceptable as attitudes to hygiene have changed. Thirdly, modern boilers are now used for heating, so the traditional stoves which used cow pats for fuel are no longer needed. Also, it used to be children who looked after the cattle, but these days children go to the city for their education so there is no one now to take care of the cows. Since the early 2000s jak-du have disappeared as they are no longer needed. Through researching the living heritage of rural villages, we can see how various aspects of modernisation make this a complex sociocultural study.

Various women’s hand-made items survive. The possessions of Yeong-Sun Yu (80 years old), Chunchak Yi (81 years old) and Bo-im Han (86 years old) respectively, living in three remote villages, include clothes made before their marriages as well as various other handicrafts and tools. Weaving was one of the main domestic tasks women performed in traditional societies. All the processes from spinning threads such as hemp, silk, ramie, and cotton to using a loom ( gilssam ) to weave these into fabrics were an important part of daily life (Plates 6 and 7).

Koreans have always had a fondness for being clean, and their towels are perfect examples of it. These include everything from facial towels, head towels, neck towels, foot towels, and hair towels, to towels specifically used for sweating, cleansing, bathing, wiping, and scrubbing. Yeong-sun Yu made various clothes and towels to take with her when she was married in Bibong village, her hometown. She embroidered cross-stitch flowers, grass, and pheasants on cotton cloth (Plate 5). An old woman recollected that in her youth all the women of the same age in the village got together to do crossstitch. The items show not only the status of Yeong-sun Yu’s family, but also relate to the women's subculture related to bride's wedding lists at that time.

After the liberation in 1945, the silk industry was in gradual decline, yet some wealthy families in rural areas could still afford to make and use it for everyday clothes. On the other hand, imported threads and fabrics were being introduced into the villages. We learnt that in the 1950s and 1960s cotton clothing was often used as casual wear.

Hemp pants were one of the items Chun-chak Yi (81 years old) was given when she married at the age of 20 in Bongdong (Plate 8). Yi was from the Jeon-un Yi lineage, the eldest daughter of nine children, and her mother-in-law cared deeply about her bride’s wedding list. Even after the marriage, she often received clothes from her in-laws. The main feature of pants made of hemp is that the fabric ‘breathes’, making it suitable for hot summers; the pants keep the wearer cool and they are easy to wash. According to Yi, she wore the clothes on her bride’s wedding list for a couple of years and has kept them folded away ever since. Traditional Korean hemp pants worn by women are a good example of how fashion has changed.

Embroidery has long been a way of expressing Korean artistry. Bo-im Han’s (86 years old) embroidery work reveals the remarkable changes that took place in Korean embroidery after the liberation in 1945. In particular, new industrially-produced materials like acrylic, polyester and woollen threads started to be used (Sun-young Lee: 1991).  The work depicting the letter keumsu gangsan was made in 1949 by Bo-im Han, and it is meaningful because she embroidered it for her honsu or bride’s wedding list (Plate 9).

The yogang or Korean chamberpot is also important. It was one of the most common artefacts found in the survey. A yogang is a small night stool that can be placed in any of the rooms in the house. Plate 10 shows a chamberpot or bowl used by the parents of Jung-sul Park (71 years old). A few years ago there was a fire in the house and a lot was lost. Fortunately for Park, the family yogang was recovered; Park was quoted as saying ‘I am very glad.’ A yogang was a necessity in the Korean hanok (traditional house) because the toilet was often separate from the house so it was awkward to go to the toilet at night.

As a result, all households had some sort of yogang placed in each room. Park, our informant, said that he purchased some of his elderly parents’ yogangs in the market around 1920, during a very cold winter. The yogang has become one of his treasures as it reminds him of taking care of his parents who are now deceased. He remembers his father saying he should have bought alcohol with the money he spent on them! These days, his yogang , which was once cleaned daily to go in his parents' room, sits in plain view reminding him of his past.

A yogang was widely considered a necessity for all classes, and was one of the most common items on a bride’s wedding list. They were sometimes made of brass or other metals. Before her marriage, Yong-ja Eom (71 years old) of Hwa-jung village, claims that she was so poor that she was only able to bring two items from her wedding list; a yogang and a washing bowl. Also, when the palanquin was used as the main means of transportation, it was said there was always a yogang in the palanquin ( gama ). It was mainly used by upper class women. These gama yogang were quite small, about the size of a man’s fist.

Many artefacts are both tangible heritage in that they are real objects, and intangible heritage because of the stories related to them. It is a vast field. Through the above-mentioned fieldwork, it can be seen that intangible cultural heritage values can be identified directly by the residents themselves as they 'curate' their own stories about their lives and their possessions.



The tangible and intangible cultural heritage of rural life

In recent years, exhibitions have changed from being artefact-oriented to containing stories related to intangible cultural heritage. The Arirang and Blue Jeans exhibitions held by the National Folk Museum in recent years are good examples of exhibitions which explain peoples’ diverse life stories and their memories regarding their treasured artefacts. Similarly, the 70 stories of the 70th Anniversary of Liberation exhibition held at the National Museum gave a number of individual perspectives on the liberation struggle. The people living in the Dongjin River area had their life stories featured in an exhibition, running through the millennium, which was similar to this study. However, we approached our study as a way of revealing the original stories told by the villagers rather than as an interpretation or assessment by outside researchers. We recognised the integrated value of artefacts such as the jak-du , the yogang , and other hand-made items discovered in rural village areas. The reason for choosing these items is that they all belong to a common theme of arts and crafts as well as to a sub-category of intangible cultural heritage, because they have meanings which can be explained by ontological analysis.

Ontology indicates the relationships surrounding a subject. It should be noted that ontological evidence is only reliable when an expert confirms the relativity of the terminologies concerned.  Since ontological analysis is not the study of similar terms, but of the relationship of objects and stories and ideas, it requires professional insights to ensure accuracy (Han-hee Hahm et al. , 2018).

An ontological analysis of the jak-du, yogang and other handicrafts is presented above in Figure 1. The jak- du takes a different form in each household because its owner makes it for himself after purchasing the blade from a blacksmith. The yogang can be aesthetically pleasing, made from materials such as brass, bronze, bamboo, pottery or wood. Home-made handicrafts and the tools used to make them are also valuable artefacts - including looms and spinning wheels.

On the other hand, the characteristics of the living space (called jeongju gonggan - settlement space) can be well expressed by tangible objects, like the jak-du(straw cutter) and the yogang (chamber pot). The straw cutter is closely related to the use of on-dol , a system for both heating and cooking in traditional houses. The traditional night stool was also essential when the toilet was located outdoors and away from the main house. The following sentences may explain these sentiments. ‘A child hurt his foot while using the straw cutter to feed the cows while his parents were busy in the fields.’ ‘Children were worried that their parents would go to the bathroom in the dark cold winter night, so they bought a night stool for them.’ ‘A woman who got married longed for her parents and sewed clothes for them with the hemp fabric that they had given her as a wedding gift.’ These examples are all related to the Korean concept of filial piety.

The 2019 Filial Piety Culture Education Programmes of the Daejeon Hyo Culture Promotion Agency include traditional etiquette, the tea experience, the yangban(noblemen class) experience, table manners, and education in filial piety. Among other things, making hanbok (traditional dress), tea drinking and table manners were also frequently dealt with. As seen from the previous examples, artefacts such as straw cutters, night chamber pots and hemp clothes also have important intangible attributes in which social customs, morality, and consciousness are explicit.

The common value shared by the yogang and handicraft items is that they were all on wedding lists. The bride’s wedding lists detailed the things that would prepare the new couple for life after marriage, though the lists differed depending on the class and social status of the individual. In addition, women’s handicrafts also provided data showing the economic and social changes of modern times. We have learnt how women from the upper class attended 'bridal classes' in the 1940s and 1950s with their peers before marriage, and how traditional embroidery and sewing techniques have changed since imported thread and fabrics were introduced into rural villages. These tangible items allow us to connect with the intangible cultural heritage they represent. Intangible cultural heritage can thus be embodied in tangible objects. When objects are collected and displayed with their stories in a museum, the traditional tangible and living intangible heritage can provide a place of nostalgia for the old and a place of education for the young.



Conclusion

In the case of living heritage, its transmission is often disconnected; the need to protect such data should therefore always be kept in mind. In particular, in the case of data closely related to daily or domestic life, the method of intergenerational transfer must be transformed into a method of participation that enables more human interaction. In order to do this, local museums must preserve memories of the local lifestyle and its surrounding culture.

Museums collect artefacts in various ways. Acquired artefacts are preserved in warehouses with the appropriate storage environment, and are used as source data for developing plans for an exhibition. In other words, when planning a specific exhibition, the museum staff will review its collection of artefacts. However, while national museums have hundreds of artefacts; smaller museums may have very few items in their collections. Museum exhibitions can be broadly divided into permanent exhibitions, temporary exhibitions, exhibitions of collections, etc. As can be seen from the testimony of a museum official (47 years old) that the utilisation rate of artefacts in museums is 10 percent in the case of non-national museums , artefacts may have to be found by borrowing from private owners or other museums and institutions (personal interview: January 3, 2019). Preparing for such exhibitions would require academic research rather than fieldwork. Due to limited finances, manpower and preparation time, it is inevitable that for most small museums, content will be developed from existing documentation and by borrowing objects from other institutions as well as through personal networking with colleagues and collectors.

In most cases, there is not sufficient information about the artefacts in storage or documentation about their accessibility. In fact, not many records of artefacts, whether ancient or modern, in a museum provide detailed information. To provide sufficient data about artefacts, the ideal is to carry out fieldwork and collect cultural materials and information simultaneously. Fieldwork among the older rural villagers, while they are still alive, is critically important so that they can describe past events and their daily lives, or important recent changes to the village. This matters because there are still many significant artefacts in these rural villages which only the older residents can describe.

In addition, the collection of data in this way means that the residents rather than just being the subject, become the curators of their own heritage, and can tell us about the history of the village as well as about their personal histories and their social relationships. By having professional researchers do fieldwork to gather data about cultural heritage, we can identify the values of both tangible and intangible heritage. This method pays attention to the actual 'story' of the tangible material, and makes it meaningful in ways not covered by existing evaluations of tangible cultural property.

Those artefacts exhibited in relation to the intangible cultural heritage in Korea have been related to the daily life of their owners, tools used by the craftsmen who make traditional crafts, or the accessories used for ceremonies. However, as has been demonstrated through the above-mentioned examples, other types of material culture contain intangible cultural heritage values   because of the intrinsic value of knowledge about the traditional ways of life and culture of people in the past.

Surveying rural villages, we noticed that the villagers wanted the history of their villages written up in book form. However, this has not yet happened because in-depth research and analysis of the cultural resources of actual village residents has been minimal. Korea needs to think seriously about the implications of rapid modernisation and industrialisation, because local traditions, memories and material culture related to rural village culture are rapidly changing and disappearing.

Cultural artefacts are different from existing heritage surveys in that they require us to obtain interview data directly from their owners. Oral documentation helps convey the owners’ emotions and moods associated with the artefact which helps maximise our understanding. This helps protect cultural heritage by making the local people realise their own memories and items are valuable. Listening to stories about the artefacts owned by the old people of the villages in the course of conducting the surveys developed into an opportunity for the residents to value their cultural heritage anew.

In this way, we can raise awareness about the importance of cultural materials in remote rural areas. In the future, field researchers should actively survey cultural artefacts kept by villagers and explore their intrinsic intangible cultural heritage value. For this purpose, this article presents an ontological analysis of the cultural artefacts of Wanju-gun. They are the cultural outcome of technology, knowledge, values, symbolic systems, and the social interaction of people in everyday life. A museum which was able to present both the tangible and intangible heritage would be invaluable.

The time has come for museums to pursue quality of information rather than quantity of objects. Through research and survey, exhibition and public exposure, museums must discover the key values of people’s material culture and recognise its importance. ‘Rare intrinsic value or artistry’ are the qualities required for an item to meet the criteria for ‘cultural property’ in Korea, but as has been shown here, other qualities are important too.

The range of artefacts to be found in the villages may be limited, many of the items may look the same or have been used in similar ways. However, there are stories relating to many of these items and it is the stories that distinguish them and make them important. These artefacts are often undervalued; we need to find ways of recognising them as cultural property.



Acknowledgement

This work was supported by the Ministry of Education of the Republic of Korea and the National Research Foundation of Korea (NRF-2017S1A5B8057729)