Major Class Recommendation System based on Deep learning using Network Analysis (네트워크 분석을 활용한 딥러닝 기반 전공과목 추천 시스템)
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- Journal of Intelligence and Information Systems
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- v.27 no.3
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- pp.95-112
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- 2021
In university education, the choice of major class plays an important role in students' careers. However, in line with the changes in the industry, the fields of major subjects by department are diversifying and increasing in number in university education. As a result, students have difficulty to choose and take classes according to their career paths. In general, students choose classes based on experiences such as choices of peers or advice from seniors. This has the advantage of being able to take into account the general situation, but it does not reflect individual tendencies and considerations of existing courses, and has a problem that leads to information inequality that is shared only among specific students. In addition, as non-face-to-face classes have recently been conducted and exchanges between students have decreased, even experience-based decisions have not been made as well. Therefore, this study proposes a recommendation system model that can recommend college major classes suitable for individual characteristics based on data rather than experience. The recommendation system recommends information and content (music, movies, books, images, etc.) that a specific user may be interested in. It is already widely used in services where it is important to consider individual tendencies such as YouTube and Facebook, and you can experience it familiarly in providing personalized services in content services such as over-the-top media services (OTT). Classes are also a kind of content consumption in terms of selecting classes suitable for individuals from a set content list. However, unlike other content consumption, it is characterized by a large influence of selection results. For example, in the case of music and movies, it is usually consumed once and the time required to consume content is short. Therefore, the importance of each item is relatively low, and there is no deep concern in selecting. Major classes usually have a long consumption time because they have to be taken for one semester, and each item has a high importance and requires greater caution in choice because it affects many things such as career and graduation requirements depending on the composition of the selected classes. Depending on the unique characteristics of these major classes, the recommendation system in the education field supports decision-making that reflects individual characteristics that are meaningful and cannot be reflected in experience-based decision-making, even though it has a relatively small number of item ranges. This study aims to realize personalized education and enhance students' educational satisfaction by presenting a recommendation model for university major class. In the model study, class history data of undergraduate students at University from 2015 to 2017 were used, and students and their major names were used as metadata. The class history data is implicit feedback data that only indicates whether content is consumed, not reflecting preferences for classes. Therefore, when we derive embedding vectors that characterize students and classes, their expressive power is low. With these issues in mind, this study proposes a Net-NeuMF model that generates vectors of students, classes through network analysis and utilizes them as input values of the model. The model was based on the structure of NeuMF using one-hot vectors, a representative model using data with implicit feedback. The input vectors of the model are generated to represent the characteristic of students and classes through network analysis. To generate a vector representing a student, each student is set to a node and the edge is designed to connect with a weight if the two students take the same class. Similarly, to generate a vector representing the class, each class was set as a node, and the edge connected if any students had taken the classes in common. Thus, we utilize Node2Vec, a representation learning methodology that quantifies the characteristics of each node. For the evaluation of the model, we used four indicators that are mainly utilized by recommendation systems, and experiments were conducted on three different dimensions to analyze the impact of embedding dimensions on the model. The results show better performance on evaluation metrics regardless of dimension than when using one-hot vectors in existing NeuMF structures. Thus, this work contributes to a network of students (users) and classes (items) to increase expressiveness over existing one-hot embeddings, to match the characteristics of each structure that constitutes the model, and to show better performance on various kinds of evaluation metrics compared to existing methodologies.
The dispute involving the construction of the Tomb of Queen Sindeok (hereinafter "Jeongreung"), King Taejo's wife in Seoul, and the moving of that tomb, represents the most clearly demonstrated case for the collision of new and old ideologies between political powers in the early period of Joseon. Jeongreung, the tomb of Queen Sindeok from the Kang Clan, was built inside the capital fortress, but in 1409, King Taejong forced the tomb to be moved outside the capital, and the stone relics remaining at the original location were used to build the stone bridge, Gwangtong-gyo. In an unofficial story, King Taejong moved the tomb outside the capital and used the stone items there to make the Cheonggyecheon Gwang-gyo so that the people would step upon the area in order to curse Lady Kang. In the final year of King Taejo, Lady Kang and King Taejong were in a politically conflictual relationship, but they were close to being political partners until King Taejo became the king. Sillok records pertaining to the establishment of Jeongreung or Gwangtong-gyo in fact state things more plainly, indicating that the moving of Jeongreung was a result of following the sangeon (a written statement to the king) of Uijeongbu (the highest administrative agency in Joseon), which stated that having the tomb of a king or queen in the capital was inappropriate, and since it was close to the official quarter of envoys, it had to be moved. The assertion that it was aimed at degrading Jeongreung in order to repair Gwangtong-gyo thus does not reflect the factual relationship. This article presents the possibility that the use of stone items from Jeongreung to repair Gwangtong-gyo reflected an emerging need for efficient material procurement that accompanied a drastic increase in demand for materials required in civil works both in- and outside the capital. The cause for constructing Jeongreung within the capital and the cause of moving the tomb outside the capital would therefore be attributable to the heterogeneity of the ideological backgrounds of King Taejo and King Taejong. King Taejo was the ruler of the Confucius state, as he reigned through the Yeokseong Revolution, but he constructed the tomb and Hongcheon-sa, the temple in the capital for his wife Queen Sindeok. In this respect, it is considered that, with the power of Buddhism, there was an attempt to rally supporters and gather the force needed to establish the authority of Queen Sindeok. Yi Seong-gye, who was raised in the Dorugachi clan of Yuan, lived as a military man in the border area, and so he would not have had a high level of understanding in Confucian scholarship. Rather, he was a man of the old system with its 'Buddhist" tendency. On the other hand, King Taejong Yi Bang-won was an elite Confucian student who passed the national examination at the end of the Goryeo era, and he is also known to have held a profound understanding of Neo-Confucianism. To state it differently, it would be reasonable to say that the understanding of symbolic implications for the capital would be more profound in a Confucian state. Since the national system that was ruled by laws had been established following the Three-Kingdom era, the principle of burial outside of the capital that would have seen a grave constructed on the outskirts of the capital was not upheld, without exception. Jeongreung was built inside the capital due to the strong individual desire of King Taejo, but since he was a Confucian scholar prior to becoming king, it would not have been accepted as desirable. After taking the throne, King Taejong took the initiative to begin overhauling the capital in order to reflect his intent to clearly realize Confucian ideology emphasizing 'Yechi' ("ruling with good manners") with the scenic view of the Capital's Hanyang river. It would be reasonable to conclude accordingly that the moving of Jeongreung was undertaken in the context of such a historic background.
The intention of this study is to apprehend the con. tents and methods of herb remedies that are commonly conducted when there are health-problem cases of ENT, eyes, teeth and skin. Methods of this study are divided into two stages : 1) For a period of six months from December 1994 to June 1995, some 40 persons who are believed to be well versed with herb remedies have been randomly chosen, and we made a survey on herb remedies by symptoms: and 2) we have endeavored to make their grounds evident through the studies on literatures with the focus on the basic data collected. Their results are as follows: 1) When one feels a pain in ears, such herb remedies are employed as pouring the vapor into ears, which is made by steaming Alaska pollack, or as applying or wiping with the juices of radish or the ginkgo, or' alum. Applying the radish juice is effective for sterilization and fever removal: and applying the ginkgo juice is effective for cleanliness. But, plastering alum, sesame oil or castor oil, or pouring the vapor of Alaska pollack into ears are perhaps effective but do not have any pharmacologic grounds. 2) When one bleeds at the nose, such kinds of herb remedies are applied as stimulating nose or head with cold water, pressing nose or ridge of nose, or filling up nares with mashed mugworts. In addition, they have utilized garlic or leeks. Such methods as stimulating with cold water or just pressing nose and ridge of nose is based on reasonable grounds, i.e. vasoconstriction and vascular compression ; and applying mashed garlic on the sole of foot is good for the circulation of Qui ; and the use of mugworts and leeks is based upon the pharmacological function of hemostasis. 3) When one feels a sore throat such kinds of herb remedies are employed as gargling or rinsing throat with brine, drinking hot gruel or water, or drinking the juice of mugwort, radish, ginger or Chinese quince. Gargling with brine or drinking the juice of mugwort, radish or ginger is based upon the pharmacological function of pain alleviation, fever removal, and detoxication. 4) When a boil is formed in mouth, such herb remedies are applied as spreading honey, brine or alum water, and taking gall nut, Chinese matrimony vine, lotus root, etc, for drugs. Spreading honey, brine or water that is made by infusing gallnut, Chinese matrimony vine, lotus root is based upon such functions as hematosis, astriction, antibacterial, and antiphlogistic, Alum, eggplant and licorice are said to be effective, but their pharmacological effects have no grounds. 5) When one has conjunctivitis such herb remedies are commonly applied as irrigation with brine and dropping breast milk in eyes. Moreover, such other drugs are used as plantain. shepherd's purse, and purslane, etc. The use of brine, breast milk, plantain, shepherd's purse and purslane is based upon such functions as sterilization, antiphlogistic, disinfection and pain relieving. Eriocaulon sieboldianum, bean stem, bean pod and narcissus leaves are said to be effective, but their pharmacological action have no basis. When one has a stye, such herb remedies are applied as extracting eyelashes, stimulating by a massage of middle finger, third finger or big toe, as well as sear ing with a heated bamboo comb that is fine-toothed. Other than these, plantain and nightshade's nuts are used as drugs for it. Extracting eyelashes corresponds with exclusing suppurative node and draining the stye of pus ; and the use of plantain is based upon disinfection: and nightshade's nuts are said to be effective, however, their pharmacological action has no grounds. 6) For a treatment of toothache, such herb remedies are commonly employed as rinsing mouth with brine and holding cold water or gasoline in the mouth ; and as the drugs that are believed to be effective have been Welsh onion, ginger and castor-oil, plant, etc. The use of Welsh onion is based upon pain killing, antiinflammatory actions, and the use of ginger is based upon detoxication and disinfection ; and seeds of castor-oil plants are said to be effective, but they have no pharmacological basis. 7) When one has hives, such herb remedies are commonly applied as rubbing burned straw in affected parts, exposing to its smoke, rubbing with salt, sweeping down with a broom, and spreading and drinking boiled water of trifoliate orange. The use of cassia tora seeds, walnut, aloe and radish is said to be effective. The use of cassia tor a seeds has the functions of intestinal order, anti-paralysis, etc. The use of walnut has resulted in an increase of blood by invigorating spirits ; and the use of aloe is based upon disinfection, antibiotic, anti-salt, antihistamine and detoxication action. But, the effects of radish juice and straw's smoke have no pharmacological grounds. 8) When one gets a boil, such herb remedies are commonly used as applying a plaster, paste of flour mixed with yolk, soy sauce or honey, as well as spreading pounded elm tree. Other remedies that have been said to be effective are ; heating with mugwort, brine, wild rocambole, aloe, onion, squid's bone, etc. The use of mugwort is based upon pain killing, astringent antiinflammatory and tranquility. Wild rocambole is based upon the generation and maintenance functions of cell-joining textures ; elm tree upon antiphlogistic ; aloe upon fever removal and antiphlogistic ; onion on pain killing, fever removal, antiphlogistic and tranquility ; squid's bone on astriction: and brine or vinegar on sterilization. Pine resin and gardenia seed are said to be effective, but they have no pharmacological basis. 9) When one cuts his skin, such herb remedies are commonly employed as spreading mugwort's juice or squid's bone powder, or pressing the wounds. In addition, kalopanax, onion and fine soil are employed. The use of mugwort, kalopanax and squid's bone is based upon such functions as hemostasis, sedation, pain killing, antibacterial ; and fine soil is said to be effective, but it has no pharmacological basis. 10) When one suffers from whitlow, such herb remedies are commonly utilized as heating with boiled soy sauce, spreading soybean paste, or dipping into eggs, etc. Other drugs that have been employed are onion root, brine, eggplant, potato, loach, etc. The use of onion is based upon pain killing and antiphlogistic functions ; and that of brine upon antiphlogistic function. The use of soy sauce or soybean paste, fomentation, eggplant, potato and loach is said to be effective, but it has no pharmacblogic ground. 11) For the treatment of frostbite, such herb remedies are commonly used as dipping the affected part into frozen soybean sack, using boiled water of eggplant stem, garlic caulis, onion, hot pepper, caulis. Onion is based upon antiphlogistic and tranquility actions garlic upon disintection, metabolic exacerbation, tonic and aphrodisiac actions and the use of eggplant and hot pepper is based upon help blood circulation, dissolution and excretion of waste matters in vein. 12) For the treatment of burn, such herb remedies or drugs are commonly used as cleansing with Korean gin, spreading eggs, cleansing with cold water and soap water ; and as brine, cactus, moss, soybean paste, oil, etc. The cleansing with Korean gin, cold water, soap water, brine, vinegar is based upon cleaning and sterilizing functions ; and the use of cucumber is based upon nu. trition provision, and strengthening of resisting power by adjustment of metabolism. The use of potato, cactus, moss, oil and eggs is said to be effective, but their phamacological functions are not clarified. In view of the above results, we can realize that the drugs that have been employed in herb remedies are quite diverse. However, in regard to majority of herb remedies that have been employed by symptoms, the pharmacological functions of their drugs have not been clarified, and they are merely known as effective. Furthermore, they have not been recorded in the literature as yet ; and we confirm that there have been many herb remedies that were executed without the proper knowlege of their effects. It is now our view that the results of this survey may be utilized for consulting data in regard to the use of herb remedies.
Korea's first exploratory tuna fishing was done with a used longliner in 1957. Then the commercial fishing has been made steady headway since the 1960's and grown up to one of major tuna fishing countries in 1970's. The tuna fishing aimed primarily at acquiring foreign currency, then tuna was exported directly from the overseas fishing base. Tuna, however, has been gradually favored by Koreans as high-proteined foods according to the growth of GNP since the 1970's. In 1980, the canned tuna began to be produced and sold at home. And so the demand of raw tuna for cannaries has steeply increased not only for home but also for abroad, and stimulated the development of tuna purse seine fishery. The author carried out a study on the development of tuna purse seine fishery in Korea and countries concerned-the United States and Japan-because it is recognized to be significant for the further development of this fishery. Just as purse seining was originated in the United States, so tuna purse seining was also pioneered by Californian fishermen in the west coastal waters of the United States (Eastern Pacific Ocean). They started to produce the canned tuna in the early 1900's, and the demand for raw tuna began to be increased rapidly. In those days, tuna was mostly caught by pole-and-line, but the catch amount was far away from the demand. To satisfy this demand, they began to try out fishing tuna by the use of purse seine which had been born in the eastern waters in the 1820's and applied to catch white fishes in the western waters of the United States in those days. Even though their trial was technically successful through severe trial and error, a new problem was raised on the management of tuna resource and the preservation of porpoise which was occassionally caught with tuna. Then the Inter-American Tropical Tuna Commission (IATTC) was established by countries neighboring to the United States in 1950 and they set up the Commission's Yellowfin Regulatory Area (CYRA) and regulated the annual quota for yellowfin. Then, American owners tried to send their seiners to the Western African waters to expand the fishing ground in 1967 and to the Centeral-Western Pacfic in 1974, and the fishing ground was widely expanded. The number of the United States' purse seiners amounted to about 150 in 1980, but the enthusiasm was gradually cooled thereafter and the number of seiner was decreased to 67 in 1986. The landing of tuna by purse seiners in the United States after 1980 maintains 200 thousands M/T or so with a little increase despite the decreasing of domestic seiners. This shows that the landing by foreign seiners are increasing, compared with the landing by domestic seiners are decreasing. In Japan, even though purse seining was introduced in 1880, they had fished tuna by longline and pole-and -line until the tuna purse seining was introduced from the United States again. In the 1960's, Japanese tuna seiners made the exploratory fishing in the South-western Pacific and West African waters with a limited success. In 1971, the government-funded research center "JARMRAC" conducted the exploratory fishing which extended to the Central American waters, the Asia-Pacific Region and the South-western Pacific. It had also much difficulties, till they improved the fishing gear adaptable to the new fishing condition in the South-western Pacific. Japanese government has begun to licence 32 single seiners and 7 group seiners since 1980 and their standard has lasted up to now. The catch in the Pacific Islands Region amounted to 160 thousands M/T in 1986. Korea's tuna purse seine fishery was originated in 1971 by Jedong Industrial Co., Ltd. with three used tuna purse seiners purchased from the United States, and they began to fish in the Eastern Pacific, but failed owing to the superannuation of vessel and the infancy of fishing technique. The second challenge was done by Dongwon Industrial Co., Ltd. in 1979, with one used seiner purchased from the United States, and started to fish in the Eastern Pacific. Even though the first trial was almost unsuccessful but they could obtain the noticeable success by removing the vessel to the South-western Pacific in 1980. This success stimulated the Korean entherprisers to take part in this fishery, and the number of Korean tuna purse seiners has been increased rapidly in accordance with the increased demand for raw tuna. The number of vessels actually at work amounted to 36 in 1990 and they operate in the South-western Pacific. The annual catch of tuna by purse seiners amounted to 170 thousands M/T in 1990 and ranked to one of the major tuna purse seining countries in the world.