• Title/Summary/Keyword: '한 책'

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Incorporating Social Relationship discovered from User's Behavior into Collaborative Filtering (사용자 행동 기반의 사회적 관계를 결합한 사용자 협업적 여과 방법)

  • Thay, Setha;Ha, Inay;Jo, Geun-Sik
    • Journal of Intelligence and Information Systems
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    • v.19 no.2
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    • pp.1-20
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    • 2013
  • Nowadays, social network is a huge communication platform for providing people to connect with one another and to bring users together to share common interests, experiences, and their daily activities. Users spend hours per day in maintaining personal information and interacting with other people via posting, commenting, messaging, games, social events, and applications. Due to the growth of user's distributed information in social network, there is a great potential to utilize the social data to enhance the quality of recommender system. There are some researches focusing on social network analysis that investigate how social network can be used in recommendation domain. Among these researches, we are interested in taking advantages of the interaction between a user and others in social network that can be determined and known as social relationship. Furthermore, mostly user's decisions before purchasing some products depend on suggestion of people who have either the same preferences or closer relationship. For this reason, we believe that user's relationship in social network can provide an effective way to increase the quality in prediction user's interests of recommender system. Therefore, social relationship between users encountered from social network is a common factor to improve the way of predicting user's preferences in the conventional approach. Recommender system is dramatically increasing in popularity and currently being used by many e-commerce sites such as Amazon.com, Last.fm, eBay.com, etc. Collaborative filtering (CF) method is one of the essential and powerful techniques in recommender system for suggesting the appropriate items to user by learning user's preferences. CF method focuses on user data and generates automatic prediction about user's interests by gathering information from users who share similar background and preferences. Specifically, the intension of CF method is to find users who have similar preferences and to suggest target user items that were mostly preferred by those nearest neighbor users. There are two basic units that need to be considered by CF method, the user and the item. Each user needs to provide his rating value on items i.e. movies, products, books, etc to indicate their interests on those items. In addition, CF uses the user-rating matrix to find a group of users who have similar rating with target user. Then, it predicts unknown rating value for items that target user has not rated. Currently, CF has been successfully implemented in both information filtering and e-commerce applications. However, it remains some important challenges such as cold start, data sparsity, and scalability reflected on quality and accuracy of prediction. In order to overcome these challenges, many researchers have proposed various kinds of CF method such as hybrid CF, trust-based CF, social network-based CF, etc. In the purpose of improving the recommendation performance and prediction accuracy of standard CF, in this paper we propose a method which integrates traditional CF technique with social relationship between users discovered from user's behavior in social network i.e. Facebook. We identify user's relationship from behavior of user such as posts and comments interacted with friends in Facebook. We believe that social relationship implicitly inferred from user's behavior can be likely applied to compensate the limitation of conventional approach. Therefore, we extract posts and comments of each user by using Facebook Graph API and calculate feature score among each term to obtain feature vector for computing similarity of user. Then, we combine the result with similarity value computed using traditional CF technique. Finally, our system provides a list of recommended items according to neighbor users who have the biggest total similarity value to the target user. In order to verify and evaluate our proposed method we have performed an experiment on data collected from our Movies Rating System. Prediction accuracy evaluation is conducted to demonstrate how much our algorithm gives the correctness of recommendation to user in terms of MAE. Then, the evaluation of performance is made to show the effectiveness of our method in terms of precision, recall, and F1-measure. Evaluation on coverage is also included in our experiment to see the ability of generating recommendation. The experimental results show that our proposed method outperform and more accurate in suggesting items to users with better performance. The effectiveness of user's behavior in social network particularly shows the significant improvement by up to 6% on recommendation accuracy. Moreover, experiment of recommendation performance shows that incorporating social relationship observed from user's behavior into CF is beneficial and useful to generate recommendation with 7% improvement of performance compared with benchmark methods. Finally, we confirm that interaction between users in social network is able to enhance the accuracy and give better recommendation in conventional approach.

New Trends in the Production of One Hundred Fans Paintings in the Late Joseon Period: The One Hundred Fans Painting in the Museum am Rothenbaum Kulturen und Künste der Welt in Germany and Its Original Drawings at the National Museum of Korea (조선말기 백선도(百扇圖)의 새로운 제작경향 - 독일 로텐바움세계문화예술박물관 소장 <백선도(百扇圖)>와 국립중앙박물관 소장 <백선도(百扇圖) 초본(草本)>을 중심으로 -)

  • Kwon, Hyeeun
    • MISULJARYO - National Museum of Korea Art Journal
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    • v.96
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    • pp.239-260
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    • 2019
  • This paper examines the circulation and dissemination of painting during and after the nineteenth century through a case study on the One Hundred Fans paintings produced as decorative folding screens at the time. One Hundred Fans paintings refer to depictions of layers of fans in various shapes on which pictures of diverse themes are drawn. Fans and paintings on fans were depicted on paintings before the nineteenth century. However, it was in the nineteenth century that they began to be applied as subject matter for decorative paintings. Reflecting the trend of enjoying extravagant hobbies, fans and paintings on fans were mainly produced as folding screens. The folding screen of One Hundred Fans from the collection of the Museum am Rothenbaum Kulturen und Künste der Welt (hereafter Rothenbaum Museum) in Germany was first introduced to Korean in the exhibition The City in Art, Art in the City held at the National Museum of Korea in 2016. Each panel in this six-panel folding screen features more than five different fans painted with diverse topics. This folding screen is of particular significance since the National Museum of Korea holds the original drawings. In the nineteenth century, calligraphy and painting that had formerly been enjoyed by Joseon royal family members and the nobility in private spaces began to spread among common people and was distributed through markets. In accordance with the trend of adorning households, colorful decorative paintings were preferred, leading to the popularization of the production of One Hundred Fans folding screens with pictures in different shapes and themes. A majority of the Korean collection in the Rothenbaum Museum belonged to Heinrich Constantin Eduard Meyer(1841~1926), a German businessman who served as the Joseon consul general in Germany. From the late 1890s until 1905, Meyer traveled back and forth between Joseon and Germany and collected a wide range of Korean artifacts. After returning to Germany, he sequentially donated his collections, including One Hundred Fans, to the Rothenbaum Museum. Folding screens like One Hundred Fans with their fresh and decorative beauty may have attracted the attention of foreigners living in Joseon. The One Hundred Fans at the Rothenbaum Museum is an intriguing work in that during its treatment, a piece of paper with the inscription of the place name "Donghyeon" was found pasted upside down on the back of the second panel. Donghyeon was situated in between Euljiro 1-ga and Euljiro 2-ga in present-day Seoul. During the Joseon Dynasty, a domestic handicraft industry boomed in the area based on licensed shops and government offices, including the Dohwaseo (Royal Bureau of Painting), Hyeminseo (Royal Bureau of Public Dispensary), and Jangagwon (Royal Bureau of Music). In fact, in the early 1900s, shops selling calligraphy and painting existed in Donghyeon. Thus, it is very likely that the shops where Meyer purchased his collection of calligraphy and painting were located in Donghyeon. The six-panel folding screen One Hundred Fans in the collection of the Rothenbaum Museum is thought to have acquired its present form during a process of restoring Korean artifacts works in the 1980s. The original drawings of One Hundred Fans currently housed in the National Museum of Korea was acquired by the National Folk Museum of Korea between 1945 and 1950. Among the seven drawings of the painting, six indicate the order of their panels in the margins, which relates that the painting was originally an eight-panel folding screen. Each drawing shows more than five different fans. The details of these fans, including small decorations and patterns on the ribs, are realistically depicted. The names of the colors to be applied, including 'red ocher', 'red', 'ink', and 'blue', are written on most of the fans, while some are left empty or 'oil' is indicated on them. Ten fans have sketches of flowers, plants, and insects or historical figures. A comparison between these drawings and the folding screen of One Hundred Fans at the Rothenbaum Museum has revealed that their size and proportion are identical. This shows that the Rothenbaum Museum painting follows the directions set forth in the original drawings. The fans on the folding screen of One Hundred Fans at the Rothenbaum Museum are painted with images on diverse themes, including landscapes, narrative figures, birds and flowers, birds and animals, plants and insects, and fish and crabs. In particular, flowers and butterflies and fish and crabs were popular themes favored by nineteenth century Joseon painters. It is noteworthy that the folding screen One Hundred Fans at the Rothenbaum Museum includes several scenes recalling the typical painting style of Kim Hong-do, unlike other folding screens of One Hundred Fans or Various Paintings and Calligraphy. As a case in point, the theme of "Elegant Gathering in the Western Garden" is depicted in the Rothenbaum folding screen even though it is not commonly included in folding screens of One Hundred Fans or One Hundred Paintings due to spatial limitations. The scene of "Elegant Gathering in the Western Garden" in the Rothenbaum folding screen bears a resemblance to Kim Hong-do's folding screen of Elegant Gathering in the Western Garden at the National Museum of Korea in terms of its composition and style. Moreover, a few scenes on the Rothenbaum folding screen are similar to examples in the Painting Album of Byeongjin Year produced by Kim Hong-do in 1796. The painter who drew the fan paintings on the Rothenbaum folding screen is presumed to have been influenced by Kim Hong-do since the fan paintings of a landscape similar to Sainsam Rock, an Elegant Gathering in the Western Garden, and a Pair of Pheasants are all reminiscent of Kim's style. These paintings in the style of Kim Hong-do are reproduced on the fans left empty in the original drawings. The figure who produced both the original drawings and fan paintings appears to have been a professional painter influenced by Kim Hong-do. He might have appreciated Kim's Painting Album of Byeongjin Year or created duplicates of Painting Album of Byeongjin Year for circulation in the art market. We have so far identified about ten folding screens remaining with the One Hundred Fans. The composition of these folding screens are similar each other except for a slight difference in the number and proportion of the fans or reversed left and right sides of the fans. Such uniform composition can be also found in the paintings of scholar's accoutrements in the nineteenth century. This suggests that the increasing demand for calligraphy and painting in the nineteenth century led to the application of manuals for the mass production of decorative paintings. As the demand for colorful decorative folding screens with intricate designs increased from the nineteenth century, original drawings began to be used as models for producing various paintings. These were fully utilized when making large-scale folding screens with images such as Guo Ziyi's Enjoyment-of-Life Banquet, Banquet of the Queen Mother of the West, One Hundred Children, and the Sun, Cranes and Heavenly Peaches, all of which entailed complicated patterns. In fact, several designs repeatedly emerge in the extant folding screens, suggesting the use of original drawings as models. A tendency toward using original drawings as models for producing folding screens in large quantities in accordance with market demand is reflected in the production of the folding screens of One Hundred Fans filled with fans in different shapes and fan paintings on diverse themes. In the case of the folding screens of One Hundred Paintings, bordering frames are drawn first and then various paintings are executed inside the frames. In folding screens of One Hundred Fans, however, fans in diverse forms were drawn first. Accordingly, it must have been difficult to produce them in bulk. Existing examples are relatively fewer than other folding screens. As discussed above, the folding screen of One Hundred Fans at the Rothenbaum Museum and its original drawings at the National Museum of Korea aptly demonstrate the late Joseon painting trend of embracing and employing new painting styles. Further in-depth research into the Rothenbaum painting is required in that it is a rare example exhibiting the influence of Kim Hong-do compared to other paintings on the theme of One Hundred Fans whose composition and painting style are more similar to those found in the work of Bak Gi-jun.

Environmental Interpretation on soil mass movement spot and disaster dangerous site for precautionary measures -in Peong Chang Area- (산사태발생지(山沙汰發生地)와 피해위험지(被害危險地)의 환경학적(環境學的) 해석(解析)과 예방대책(豫防對策) -평창지구(平昌地區)를 중심(中心)으로-)

  • Ma, Sang Kyu
    • Journal of Korean Society of Forest Science
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    • v.45 no.1
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    • pp.11-25
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    • 1979
  • There was much mass movement at many different mountain side of Peong Chang area in Kwangwon province by the influence of heavy rainfall through August/4 5, 1979. This study have done with the fact observed through the field survey and the information of the former researchers. The results are as follows; 1. Heavy rainfall area with more than 200mm per day and more than 60mm per hour as maximum rainfall during past 6 years, are distributed in the western side of the connecting line through Hoeng Seong, Weonju, Yeongdong, Muju, Namweon and Suncheon, and of the southern sea side of KeongsangNam-do. The heavy rain fan reason in the above area seems to be influenced by the mouktam range and moving direction of depression. 2. Peak point of heavy rainfall distribution always happen during the night time and seems to cause directly mass movement and serious damage. 3. Soil mass movement in Peongchang break out from the course sandy loam soil of granite group and the clay soil of lime stone and shale. Earth have moved along the surface of both bedrock or also the hardpan in case of the lime stone area. 4. Infiltration seems to be rapid on the both bedrock soil, the former is by the soil texture and the latter is by the crumb structure, high humus content and dense root system in surface soil. 5. Topographic pattern of mass movement spot is mostly the concave slope at the valley head or at the upper part of middle slope which run-off can easily come together from the surrounding slope. Soil profile of mass movement spot has wet soil in the lime stone area and loose or deep soil in the granite area. 6. Dominant slope degree of the soil mass movement site has steep slope, mostly, more than 25 degree and slope position that start mass movement is mostly in the range of the middle slope line to ridge line. 7. Vegetation status of soil mass movement area are mostly fire field agriculture area, it's abandoned grass land, young plantation made on the fire field poor forest of the erosion control site and non forest land composed mainly grass and shrubs. Very rare earth sliding can be found in the big tree stands but mostly from the thin soil site on the un-weatherd bed rock. 8. Dangerous condition of soil mass movement and land sliding seems to be estimated by the several environmental factors, namely, vegetation cover, slope degree, slope shape and position, bed rock and soil profile characteristics etc. 9. House break down are mostly happen on the following site, namely, colluvial cone and fan, talus, foot area of concave slope and small terrace or colluvial soil between valley and at the small river side Dangerous house from mass movement could be interpreted by the aerial photo with reference of the surrounding site condition of house and village in the mountain area 10. As a counter plan for the prevention of mass movement damage the technics of it's risk diagnosis and the field survey should be done, and the mass movement control of prevention should be started with the goverment support as soon as possible. The precautionary measures of house and village protection from mass movement damage should be made and executed and considered the protecting forest making around the house and village. 11. Dangerous or safety of house and village from mass movement and flood damage will be indentified and informed to the village people of mountain area through the forest extension work. 12. Clear cutting activity on the steep granite site, fire field making on the steep slope, house or village construction on the dangerous site and fuel collection in the eroded forest or the steep forest land should be surely prohibited When making the management plan the mass movement, soil erosion and flood problem will be concidered and also included the prevention method of disaster.

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Changes in Agricultural Extension Services in Korea (한국농촌지도사업(韓國農村指導事業)의 변동(變動))

  • Fujita, Yasuki;Lee, Yong-Hwan;Kim, Sung-Soo
    • Journal of Agricultural Extension & Community Development
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    • v.7 no.1
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    • pp.155-166
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    • 2000
  • When the marcher visited Korea in fall 1994, he was shocked to see high rise apartment buildings around the capitol region including Seoul and Suwon, resulting from rising demand of housing because of urban migration followed by second and third industrial development. After 6 years in March 2000, the researcher witnessed more apartment buildings and vinyl house complexes, one of the evidences of continued economic progress in Korea. Korea had to receive the rescue finance from International Monetary Fund (IMF) because of financial crisis in 1997. However, the sign of recovery was seen in a year, and the growth rate of Gross Domestic Products (GDP) in 1999 recorded as high as 10.7 percent. During this period, the Korean government has been working on restructuring of banks, enterprises, labour and public sectors. The major directions of government were; localization, reducing administrative manpower, limiting agricultural budgets, privatization of public enterprises, integration of agricultural organization, and easing of various regulations. Thus, the power of central government shifted to local government resulting in a power increase for city mayors and county chiefs. Agricultural extension services was one of targets of government restructuring, transferred to local governments from central government. At the same time, the number of extension offices was reduced by 64 percent, extension personnel reduced by 24 percent, and extension budgets reduced. During the process of restructuring, the basic direction of extension services was set by central Rural Development Administration Personnel management, technology development and supports were transferred to provincial Rural Development Administrations, and operational responsibilities transferred to city/county governments. Agricultural extension services at the local levels changed the name to Agricultural Technology Extension Center, established under jurisdiction of city mayor or county chief. The function of technology development works were added, at the same time reducing the number of educators for agriculture and rural life. As a result of observations of rural areas and agricultural extension services at various levels, functional responsibilities of extension were not well recognized throughout the central, provincial, and local levels. Central agricultural extension services should be more concerned about effective rural development by monitoring provincial and local level extension activities more throughly. At county level extension services, it may be desirable to add a research function to reflect local agricultural technological needs. Sometimes, adding administrative tasks for extension educators may be helpful far farmers. However, tasks such as inspection and investigation should be avoided, since it may hinder the effectiveness of extension educational activities. It appeared that major contents of the agricultural extension service in Korea were focused on saving agricultural materials, developing new agricultural technology, enhancing agricultural export, increasing production and establishing market oriented farming. However these kinds of efforts may lead to non-sustainable agriculture. It would be better to put more emphasis on sustainable agriculture in the future. Agricultural extension methods in Korea may be better classified into two approaches or functions; consultation function for advanced farmers and technology transfer or educational function for small farmers. Advanced farmers were more interested in technology and management information, while small farmers were more concerned about information for farm management directions and timely diffusion of agricultural technology information. Agricultural extension service should put more emphasis on small farmer groups and active participation of farmers in these groups. Providing information and moderate advice in selecting alternatives should be the major activities for consultation for advanced farmers, while problem solving processes may be the major educational function for small farmers. Systems such as internet and e-mail should be utilized for functions of information exchange. These activities may not be an easy task for decreased numbers of extension educators along with increased administrative tasks. It may be difficult to practice a one-to-one approach However group guidance may improve the task to a certain degree.

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Analysis of Management Status and Optimum Production Scale of Quarrying Firms in Korea -Comparative Analysis of Aggregate and Building-Stone Quarrying Firms- (산지채석업체(山地採石業體)의 경영실태(經營實態) 및 적정규모설정(適正規模設定) -골재용(骨材用) 채석업체(採石業體)와 건축용(建築用) 채석업체(採石業體)의 비교(比較) 분석(分析)-)

  • Joung, Ha Hyeon;Cho, Eung Hyouk
    • Journal of Korean Society of Forest Science
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    • v.80 no.1
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    • pp.72-81
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    • 1991
  • This study was carried out to provide necessary information for improving quarrying industry management in Korea. The results of the study are summarized as follows : 1. In aggregate and building-stone quarrying firms the managers over 40 years of age are 97% and 89.1%, the ones above education level of high school are 90% and 85% and the ones not more than 10 years of quarrying experience are 70% and 52%, respectively. Accordingly it can be pointed out that most of the managers of two types of firms are relatively old, have high educational background, while quarrying experiences of building-stone firm managers are longer than that of aggregate firm managers. 2. Most of the management forms are social corporation(60%) for aggregate quarry firms and private management(76%) for building-stone firms. Average areas of permitted stone-pits of aggregate and building-stone quarries are about 2.86ha and 1.66ha respectively. That is, aggregate quarrying firms are carried on a larger scale than building-stone quarrying firms. 3. The yearly average product of aggregate quarrying firms has increased steadily from $88.961m^3$ in 1985 to $144.028m^3$ in 1988, while, in case of building-stone quarry firms, it has significantly increased from $4.155m^3$ to $19.462m^3$ from 1985 to 1987, but reduced to $13.400m^3$ in 1988. Unstable production activities of building-stone quarrying firms may require continuous government support. 4. Major cost items are equipment rental, depreciation, salaries, repair, maintenance for aggregate quarrying firms, and salaries, depreciation, fuel, tax for building-stone quarrying firms. The yearly average rate of return is about 9.7% for aggregate quarry firms and 2.6% for building-stone quarry firms. It can be pointed out that aggregate quarrying firms is better managed than building-stone quarrying firms. 5. The production elasticity of salary for aggregate quarrying firms is 0.495, that of employees is 0.559, and that of capital service is 0.513. The sum of the elasticities is 1.257>1. Fur building-stone quarrying firms, that of employees is 0.492, that of variable costs is 0.192, and that of capital service is 0.498. The sum of elasticities is 1.172>1, thus denotes the increasing returns to scale for both types quarrying firms. 6. The ratio of marginal value product to opportunity cost of empolyees is 2.54, that of variable costs is 3.62, and that of capital service is 1.45, in aggregate quarrying firms. That of employees is 2.47, that is variable costs was 2.34, and that of capital service is 19.67 in building-stone quarrying firms. Therefore the critical factors for more expansion of management scale in aggregate quarrying firms are variable cost and employees, and are capital service in building-stone quarry ing firms. 7. The break-even points of stone sales are about 0.587 billion won and 0.22 billion won in aggregate and building-stone quarrying firms respectively. The optimum sales Level for profit maximization are about 2.0 billion and 0.5 billion in aggregate and building-stone quarry firms respectively.

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Studies on the Varietal Difference in the Physiology of Ripening in Rice with Special Reference to Raising the Percentage of Ripened Grains (수도 등숙의 품종간차이와 그 향상에 관한 연구)

  • Su-Bong Ahn
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.14
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    • pp.1-40
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    • 1973
  • There is a general tendency to increase nitrogen level in rice production to insure an increased yield. On the other hand, percentage of ripened grains is getting decreased with such an increased fertilizer level. Decreasing of the percentage is one of the important yield limiting factors. Especially the newly developed rice variety, 'Tongil' is characterized by a relatively low percentage of ripened grains as compared with the other leading varieties. Therefore, these studies were aimed to finding out of some measures for the improvement of ripening in rice. The studies had been carried out in the field and in the phytotron during the period of three years from 1970 to 1972 at the Crop Experiment Station in Suwon. The results obtained from the experiments could be summarized as follows: 1. The spikelet of Tongil was longer in length, more narrow in width, thinner in thickness, smaller in the volume of grains and lighter in grain weight than those of Jinheung. The specific gravity of grain was closely correlated with grain weight and the relationship with thickness, width and length was getting smaller in Jinheung. On the other hand, Tongil showed a different pattern from Jinheung. The relationship of the specific gravity with grain weight was the greatest and followed by that with the width, thickness and length, in order. 2. The distribution of grain weight selected by specific gravity was different from one variety to another. Most of grains of Jinheung were distributed over the specific gravity of 1.12 with its peak at 1.18, but many of grains of Tongil were distributed below 1.12 with its peak at 1.16. The brown/rough rice ratio was sharply declined below the specific gravity of 1.06 in Jinheung, but that of Tongil was not declined from the 1.20 to the 0.96. Accordingly, it seemed to be unfair to make the specific gravity criterion for ripened grains at 1.06 in the Tongil variety. 3. The increasing tendency of grain weight after flowering was different depending on varieties. Generally speaking, rice varieties originated from cold area showed a slow grain weight increase while Tongil was rapid except at lower temperature in late ripening stage. 4. In the late-tillered culms or weak culms, the number of spikelets was small and the percentage of ripened grains was low. Tongil produced more late-tillered culms and had a longer flowering duration especially at lower temperature, resulting in a lower percentage of ripened grains. 5. The leaf blade of Tongil was short, broad and errect, having light receiving status for photosynthesis was better. The photosynthetic activity of Tongil per unit leaf area was higher than that of Jinheung at higher temperature, but lower at lower temperature. 6. Tongil was highly resistant to lodging because of short culm length, and thick lower-internodes. Before flowering, Tongil had a relatively higher amount of sugars, phosphate, silicate, calcium, manganese and magnesium. 7. The number of spikelets of Tongil was much more than that of Jinheung. The negative correlation was observed between the number of spikelets and percentage of ripened grains in Jinheung, but no correlation was found in Tongil grown at higher temperature. Therefore, grain yield was increased with increased number of spikelets in Tongil. Anthesis was not occurred below 21$^{\circ}C$ in Tongil, so sterile spikelets were increased at lower temperature during flowering stage. 8. The root distribution of Jinheung was deeper than that of Tongil. The root activity of Tongil evaluated by $\alpha$-naphthylamine oxidation method, was higher than that of Jinheung at higher temperature, but lower at lower temperature. It is seemed to be related with discoloration of leaf blades. 9. Tongil had a better light receiving status for photosynthesis and a better productive structure with balance between photosynthesis and respiration, so it is seemed that tongil has more ideal plant type for getting of a higher grain yield as compared with Jinheung. 10. Solar radiation during the 10 days before to 30 days after flowering seemed enough for ripening in suwon, but the air temperature dropped down below 22$^{\circ}C$ beyond August 25. Therefore, it was believed that air temperature is one of ripening limiting factors in this case. 11. The optimum temperature for ripening in Jinheung was relatively lower than that of Tongil requriing more than $25^{\circ}C$. Air temperature below 21$^{\circ}C$ was one of limiting factors for ripening in Tongil. 12. It seemed that Jinheung has relatively high photosensitivity and moderate thermosensitivity, while Tongil has a low photosensitivity, high thermosensitivity and longer basic vegetative phase. 13. Under a condition of higher nitrogen application at late growing stage, the grain yield of Jinheung was increased with improvement of percentage of ripened grains, while grain yield of Tongil decreased due to decreasing the number of spikelets although photosynthetic activity after flowering was. increased. 14. The grain yield of Jinheung was decreased slightly in the late transplanting culture since its photosynthetic activity was relatively high at lower temperature, but that of Tonil was decreased due to its inactive photosynthetic activity at lower temperature. The highest yield of Tongil was obtained in the early transplanting culture. 15. Tongil was adapted to a higher fertilizer and dense transplanting, and the percentage of ripened grains was improved by shortening of the flowering duration with increased number of seedlings per hill. 16. The percentage of vigorous tillers was increased with a denser transplanting and increasing in number of seedlings per hill. 17. The possibility to improve percentage of ripened grains was shown with phosphate application at lower temperature. The above mentioned results are again summarized below. The Japonica type leading varieties should be flowered before August 20 to insure a satisfactory ripening of grains. Nitrogen applied should not be more than 7.5kg/10a as the basal-dressing and the remained nitrogen should be applied at the later growing stage to increase their photosynthetic activity. The morphological and physiological characteristics of Tongil, a semi-dwarf, Indica $\times$ Japonica hybrid variety, are very different from those of other leading rice varieties, requring changes in seed selection by specific gravity method, in milling and in the cultural practices. Considering the peculiar distribution of grains selected by the method and the brown/rough rice ratio, the specific gravity criterion for seed selection should be changed from the currently employed 1.06 to about 0.96 for Tongil. In milling process, it would be advisable to bear in mind the specific traits of Tongil grain appearance. Tongil is a variety with many weak tillers and under lower temperature condition flowering is delayed. Such characteristics result in inactivation of roots and leaf blades which affects substantially lowering of the percentage of ripened grains due to increased unfertilized spikelets. In addition, Tongil is adapted well to higher nitrogen application. Therefore, it would be recommended to transplant Tongil variety earlier in season under the condition of higer nitrogen, phosphate and silicate. A dense planting-space with three vigorous seedlings per hill should be practiced in this case. In order to manifest fully the capability of Tongil, several aspects such as the varietal improvement, culural practices and milling process should be more intensively considered in the future.he future.

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