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A STUDY ON THE IONOSPHERE AND THERMOSPHERE INTERACTION BASED ON NCAR-TIEGCM: DEPENDENCE OF THE INTERPLANETARY MAGNETIC FIELD (IMF) ON THE MOMENTUM FORCING IN THE HIGH-LATITUDE LOWER THERMOSPHERE (NCAR-TIEGCM을 이용한 이온권과 열권의 상호작용 연구: 행성간 자기장(IMF)에 따른 고위도 하부 열권의 운동량 강제에 대한 연구)

  • Kwak, Young-Sil;Richmond, Arthur D.;Ahn, Byung-Ho;Won, Young-In
    • Journal of Astronomy and Space Sciences
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    • v.22 no.2
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    • pp.147-174
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    • 2005
  • To understand the physical processes that control the high-latitude lower thermospheric dynamics, we quantify the forces that are mainly responsible for maintaining the high-latitude lower thermospheric wind system with the aid of the National Center for Atmospheric Research Thermosphere-Ionosphere Electrodynamics General Circulation Model (NCAR-TIEGCM). Momentum forcing is statistically analyzed in magnetic coordinates, and its behavior with respect to the magnitude and orientation of the interplanetary magnetic field (IMF) is further examined. By subtracting the values with zero IMF from those with non-zero IMF, we obtained the difference winds and forces in the high-latitude 1ower thermosphere(<180 km). They show a simple structure over the polar cap and auroral regions for positive($B_y$ > 0.8|$\overline{B}_z$ |) or negative($B_y$ < -0.8|$\overline{B}_z$|) IMF-$\overline{B}_y$ conditions, with maximum values appearing around -80$^{\circ}$ magnetic latitude. Difference winds and difference forces for negative and positive $\overline{B}_y$ have an opposite sign and similar strength each other. For positive($B_z$ > 0.3125|$\overline{B}_y$|) or negative($B_z$ < -0.3125|$\overline{B}_y$|) IMF-$\overline{B}_z$ conditions the difference winds and difference forces are noted to subauroral latitudes. Difference winds and difference forces for negative $\overline{B}_z$ have an opposite sign to positive $\overline{B}_z$ condition. Those for negative $\overline{B}_z$ are stronger than those for positive indicating that negative $\overline{B}_z$ has a stronger effect on the winds and momentum forces than does positive $\overline{B}_z$ At higher altitudes(>125 km) the primary forces that determine the variations of tile neutral winds are the pressure gradient, Coriolis and rotational Pedersen ion drag forces; however, at various locations and times significant contributions can be made by the horizontal advection force. On the other hand, at lower altitudes(108-125 km) the pressure gradient, Coriolis and non-rotational Hall ion drag forces determine the variations of the neutral winds. At lower altitudes(<108 km) it tends to generate a geostrophic motion with the balance between the pressure gradient and Coriolis forces. The northward component of IMF By-dependent average momentum forces act more significantly on the neutral motion except for the ion drag. At lower altitudes(108-425 km) for negative IMF-$\overline{B}_y$ condition the ion drag force tends to generate a warm clockwise circulation with downward vertical motion associated with the adiabatic compress heating in the polar cap region. For positive IMF-$\overline{B}_y$ condition it tends to generate a cold anticlockwise circulation with upward vertical motion associated with the adiabatic expansion cooling in the polar cap region. For negative IMF-$\overline{B}_z$ the ion drag force tends to generate a cold anticlockwise circulation with upward vertical motion in the dawn sector. For positive IMF-$\overline{B}_z$ it tends to generate a warm clockwise circulation with downward vertical motion in the dawn sector.

A student on the Nursing Needs and Satisfaction of Primipara During the Early Postpartum Period (산욕기 초산모의 간호요구와 만족도에 관한 연구)

  • Chun, Young-Ja
    • Women's Health Nursing
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    • v.3 no.1
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    • pp.5-27
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    • 1997
  • This study was carried out to identify the difference between nursing needs and levels of satisfaction of primiparae during the early postpartum period. The goal of the study was to obtain data needed to develope maternal education programs and to improve the nursing quality for primipara. The subjects were 111 primiparae who had normal delivery at 2 general hospitals in the Seoul area. The data was gathered using an 81 items questionnaire which was developed by the researcher from Nov. 30, 1995 to Feb. 5, 1996. Results found are as follows : 1. The characteristics of subjects : The majority of subjects were aged 26-30yrs(60.4%), high school graduated(49.5%), jobless(52.3%), had no religion(49.5%), no antenatal(74.5%), and postnatal education on self and infant care(55.9%). A large proportion of primiparae intended to feed breast milk(49.5%) but in fact only 7.2% fed breast milk while in the hospital. Many subjects perceived that they had reasonable self confidence about self care(46.8%), and infant care(36%). 2. The level of nursing needs of overall nursing care was relatively high(Mn 3.98) but the level of satisfaction was of average level(Mn 3.09). Therefore, difference between the level of nursing needs and satisfaction was significant(p=0.0001). 3. The nursing needs by category of nursing care the highest need was on the education of infant care(4.29), the lowest was on physical care(3.80). The level of satisfaction was higher on environmental care(3.40) and physical care(3.32). But the category that showed the lowest satisfaction was education of infant care(2.67). Hence, difference of categories between the level of nursing needs and satisfaction was significant(p=0.0001). 4. Among items of physical care, observation of primiparas' conditions(4.21), accurate medication and treatment(4.18), care of breast engorgement(4.07) and control of postpartal hemorrage(4.01) showed high nursing needs. On the other hand, only the level of satisfaction was higher on accurate medication and treatment(3.82). The rest of items revealed only average level of satisfactions. Difference of items between the level of nursing needs and satisfaction was significant(p=0.0001) except items of dietary care. 5. Among items of psychological care, 8 items of nursing needs were high(3.72-4.29), expecially detailed explanation on which mothers want to know(4.29), treatment and nursing care they receive(4.23), kind and faithful care(4.22), early contacts with their baby(4.20), and adequate draping during the care and treatment(4.18). Among items of psychological care higher satisfactions were shown on items of kind and faithful care(3.80), personal treatment(3.70), and detailed explanation to mothers, but the least satisfied items was early contact with baby(2.13). Difference between the level of nursing needs and satisfaction was significant(p=0.0001). 6. Among items of environmental care, the highest level of need and satisfaction was on the items of neat bedding and pajamas(3.54). The difference was significant (p=0.0001). 7. Among the items of educational needs on self care, all of 22 items revealed higher educational needs(3.50-4.33) but the levels of satisfaction varied with a range of 2.63-3.42. Among the items the satisfactions were high on items of breast care including massages(3.42), perineal care(3.36) and expression of breast milk(3.32). Less satisfied items were drugs not be taken by breast milk feeder(2.63), maintenance of breast figure(2.76) and postpartum exercise(2.80) and so on. The difference was significant(p=0.0001). maintain 8. Among the items of educational needs on infant care, 19 items revealed higher educational needs(3.28-4.54). And the highest need were on the 3 items of normal growth and development of infant, safety and emergency care, symptoms of sick(4.45) and the meaning of crying of the baby(4.52). The level of satisfaction among items of education of infant care ranged from 2.47 to 3.16. Most satisfied items were buriping(3.16), bathing(3.11) and diapering(3.09). The items of which the mother's needs were high revealed the lowest satisfaction level. The difference was significant (p=0.0001). 9. Relationship between nursing needs and levels of satisfaction among primiparae of different characteristics were as follows : 1) Nursing needs of physical and psychological areas were significantly different among different age levels but no relationship was found on other categories regardless of the level of satisfaction. 2) With regard to different levels of education, some relationship was found in nursing needs of psychological area(p=0.007), educational needs on infant care(p=0.04) and environmental care(p=0.01). Also, the difference of satisfaction level was significant. 3) Working mothers had higher nursing needs and were more satisfied on items of physical care(p=0.05), education on self care and infant care. Difference were significant between nursing needs and level of satisfaction. 4) With regards to different religion a moderate relation was found between nursing needs of environmental care infant care education but no relationship was found on levels of satisfaction. 5) With regards to antenatal education, the mothers who have had no antenatal education revealed higher nursing needs on physical care but those who had antenatal education were more satisfied with education on self care and infant care. The difference was significant. (p=0.0001). 6) With regards to postpartum education, the mothers who have had some sort of postpartum education revealed higher nursing needs on physical and self care. And they were more satisfied with nursing of every category except infant care than mothers who had not any postpartum education. Differences was significant between the nursing needs and levels of satisfaction.(p=0.0001). 7) With regards to breast feeding experience during the hospitalization, those who had no experience of breast feeding revealed higher nursing needs on physical care in contrast to breast feeders, who had higher educational needs on infant care. And breast feeder were more satisfied with all categories. Differences was significant(p=0.0001). 8) With regards to perception of self confidence on self care and infant care, no relationship was found on nursing needs and level of satisfaction in every category of nursing.

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Current feeding practices and maternal nutritional knowledge on complementary feeding in Korea (이유기 보충식 현황과 어머니 인식 조사)

  • Yom, Hye Won;Seo, Jeong Wan;Park, Hyesook;Choi, Kwang Hae;Chang, Ju Young;Ryoo, Eell;Yang, Hye Ran;Kim, Jae Young;Seo, Ji Hyun;Kim, Yong Joo;Moon, Kyung Rye;Kang, Ki Soo;Park, Kie Young;Lee, Seong Soo;Shim, Jeong Ok
    • Clinical and Experimental Pediatrics
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    • v.52 no.10
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    • pp.1090-1102
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    • 2009
  • Purpose:To evaluate current feeding practices and maternal nutritional knowledge on complementary feeding. Methods:Mothers of babies aged 9-15 months who visited pediatric clinics of 14 general hospitals between September and December 2008 were asked to fill questionnaires. Data from 1,078 questionnaires were analyzed. Results:Complementary food was introduced at 4-7 months in 89% of babies. Home-made rice gruel was the first complementary food in 93% cases. Spoons were used for initial feeding in 97% cases. At 6-7 months, <50% of babies were fed meat (beef, 43%). Less than 12-month-old babies were fed salty foods such as salted laver (35%) or bean-paste soup (51%) and cow's milk (11%). The following were the maternal sources of information on complementary feeding: books/magazines (58%), friends (30%), internet web sites (29%), relatives (14%), and hospitals (4%). Compared to the 1993 survey, the incidence of complementary food introduction before 4 months (0.4% vs. 21%) and initial use of commercial food (7% vs. 39%) had decreased. Moreover, spoons were increasingly used for initial feeding (97% vs. 57%). The average maternal nutritional knowledge score was 7.5/10. Less percentage of mothers agreed with the following suggestions: bottle formula weaning before 15-18 months (68%), no commercial baby drinks as complementary food (67%), considering formula (or cow's milk) better than soy milk (65%), and feeding minced meat from 6-7 months (57%). Conclusion:Complementary feeding practices have considerably improved since the last decade. Pediatricians should advise timely introduction of appropriate complementary foods and monitor diverse information sources on complementary feeding.

Nutrition Survey in Koje Island (거제도(巨濟島) 주민(住民)의 영양실태조사(營養實態調査))

  • Oh, Seoung-Ho;Chang, Soo-Kyung;Park, Michael Myung-Yun
    • Journal of Nutrition and Health
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    • v.10 no.4
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    • pp.43-58
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    • 1977
  • Kojedo is the second largest island in Korea and a total population of 115,500 is living on the island of 394.69 sq. km. Under the direction of three nutrition professors, nutrition surveys in two villages in Kojedo, namely Siljun Ri in Hachung Myon and Soowol Ri in Shinhyun Myon, were carried by 30 college senior students majoring in nutrition from August to 20 August 1977. From a total of 176 households of the two villages, 67 households were randomly selected and 390 family members of the households were subjcets of the nutrition surveys. The precise weighing method was used in evaluating the kinds of foods and nutrient intakes of the subjects for three consecutive days. Thirty-seven pre-school children aged between 3 to 6 years and 27 fertile women were examined for biochemical findings and physical status. The main purposes of the surveys are to provide baseline data on nutrition in Kojedo Island for the Kojedo Community Development Project and to compare the nutritional status of the villages of Siljun Ri and Soowol Ri. Siljun Ri is located in the pilot project area of the Koiedo Community Health Project sponsored since December 1970 by the Christian Medical Commission of the World Council of Churches. While Soowol Ri is a control village for comparison. The results obtained are summarized as follows: Food Intake The average food intake per person per day in Siljun Ri, 1064 grams (91.7% in vegetable foods and 7.6% in animal foods) was 90 grams more than that of Soowol Ri, 974 grams (92.8% in vegetable foods and 5.9% in animal foods). However, the food intake per pre-school child in Siljun Ri, 485 grams (92.6% from vegetable foods and 6.4% from animal foods) was 21 grams lower than that of the Soowol Ri, 506 grams (88.5% from vegetable foods and 6.5% from animal foods). The average intake of beans was 16 grams(1.5% out of the total food intake) in Siljun Ri and 21 grams(2.2% of the total food intake)in Soowol Ri. The villagers should be guided for more consumption of soybeans to improve the quality of protein intake from vegetable foods. Nutrient Intake The adult intake in Siljun Ri and Soowol Ri were 2,529 kcal and 2,511 kcal respectively. The average energy intake of pre-school childen in Siljun Ri was 948 kcal and that for adult and 1,500 kcal for childen aged between 4 to 6 years-given by the Korea FAO Association, the diets in both villages were not adequate. Average daily protein intake of the subjected adult in Siljun Ri was 78.4 grams and that of Soowol Ri was 76.2 grams, while pre-school children took 30.7 grams in the former village and 31.7 grams in the latter village per child per day. The protein intake in both villages were lower than the recommended allowances, 80 grams for adult and 45 grams for $4{\sim}6$ years childen, and animal protein intake of the all subjects was very much lower than the RDA. The main charecter of the diet has been found low in quality of protein and high in carbohydrate. The calcium intakes of the pre-school children in both villages, 251.9 milligrams in Siljun Ri and 218.8 milligrams in Soowol Ri, were very much lower than the recommended allowance of 500 milligrams per day. It is apparent that the diet for children should be supplemented with calcium. Among the vitamin group, the daily average intakes of vitamin A and $B_{2}$(thiamine), $B_{2}$(riboflavin), C(ascorbic acid), and niacin were not adequate for the children in both villages. Especially the intake of riboflavin, 0.4 milligrams in both village children, was much lower than the RDA, 0.9 milligrams per day. Physical Characteristics Average height, weight, chest and head circumference of the pre-school children in both villages were similar to those of the Korean standard given by the Korean Paediatrics Association except that the average height of pre-school boys in Siljun Ri was 8 cm higher than the Korean standard of 105 cm. The mean values of upper arm circumference and skinfold thickness of pre-school boys in both villages were the same, 15.4 cm for upper arm circumference and 6.8 mm for skinfold thickness, but the mean values of those of the girls in Siljun Ri were higher than those of pre-school grils in Soowol Ri. Biochemical Findings Avera ge hemogobin value of boys and girls in both villages was the same, 11.1 grams per 100 ml of blood. The incidence of anemia (Hb value below 11g/100ml) was similar in both viltagesr 36.4% for boys and 50% for girls in Siljun Ri and 37.5% for boys and 50% for girls in Soowol Ri. Average hemoglobin values of fertile women were 10.7g% in Siljun Ri and 10.8% in Soowor Ri. The incidences of anemia(Hb valre brlow 12g/100ml) were 100% in Siljun Ri and 86.7% in Soowol Ri. The anemia of these subjects may be caused mainty low intake of good quality protein and iron intake from vegetable food. Recommendation In general, the nutritional status of a community health pilot village is not higher than that of control village due to the lack of nutrition improvement guldance services. Nutrition education should be delivered to the villagers as a main part of the health education artivities. The emphasis should be on building better health through bttter food habits and better food production as well as on preventing malnutrition and diseasrs. It can be an invaluable part of community developnent. Since nutrition is considered to be at least one-half of MCH care, no village or home visits should be made without careful provision for teaching and demoastrating something simple and practical on nutrition. The nurse, midwife, and village health worker should be the chief promoters of nutrition.

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Studies on the Assumption of the Locations and Formational Characteristics in Yigye-gugok, Mt. Bukhansan (북한산 이계구곡(耳溪九曲)의 위치비정과 집경(集景) 특성)

  • Jung, Woo-Jin;Rho, Jae-Hyun;Lee, Hee-Young
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.35 no.3
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    • pp.41-66
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    • 2017
  • The purpose of this research is to empirically trace the junctures of Yigye-gugok managed by Gwan-am Hong Gyeong-mo, a grandson of Yigye Hong Yang-ho who originally designed Yigye-gugok, while reviewing the features of the forms and patterns of gugok. The results of the research are as follows. 1. Ui-dong was part of the domain of the capital during the Chosun dynasty, which also is located in the city of Seoul as a matter of administrative zone. Likewisely, Yigye-gugok is taken as a special meaning for it was one and only gugok. Starting with Mangyeong Waterfall as the $1^{st}$ gok, Yigye follows through the $2^{nd}$ gok of Jeokchwibyeong Rock, the $3^{rd}$ gok of Chanunbong Peak, the $4^{th}$ gok of Jinuigang Rock, the $5^{th}$ gok of Okkyeongdae Rock, the $6^{th}$ gok of Wolyeongdam Pond, the $7^{th}$ gok of Tagyeongam Rock, the $8^{th}$ gok of Myeongoktan Stream, and the $9^{th}$ gok of Jaeganjeong Pavilion. Of these, Mangyeong Waterfall, Chanunbong Peak, and Okkyeongdae Rock are distinct for their locations in as much as their features, while estimated locations for Jinuigang Rock, Wolyeongdam Pond, Myeongoktan Stream, and Jaeganjeong Pavilion were discovered. However, Jeokchwibyeong Rock and Tagyeongam Rock demonstrated multiple locations in close resemblance to documentary literatures within secretive proximity, whereas geography, scenery, and sighted objects were considered to evaluate the 1st estimated location. Through these endeavored, it was possible to identify the shipping routes and structures for the total distance of 2.1km running from the $1^{st}$ gok to the $9^{th}$ gok, which nears Gwanam's description of 5ri(里), or approximately 1.96km for gugok. 2. Set towards the end of the $18^{th}$ century, Yigye-gugok originated from a series of work shaping the space of Hong Yang-ho's tomb into a space for the family. Comparing Yigye-gugok to other gugoks, numerous differences are apparent from beyond the rather more general format such as adjoining the $8^{th}$ gok while paving through the lower directions from the upper directions of the water. This gives rises to the interpretation such that Yigye-gugok was positioned to separate the doman of the family from those of the other families in power, thereby taking over Ui-dong. Yet, the aspect of the possession of the space lends itself to the determination that the location positioned at the $8^{th}$ gok above Mangyeongpok Waterfall representing Wooyi-dong was a consequence of the centrifugal space creation efforts. 3. While writings and poetic works were manufactured in such large quantities in Yigye-gugok whose products of setters and managers seemed intended towards gugok-do and letters carved on the rocks among others, there is yet a tremendous lack of visual media in the same respect. 'Yigye-gugok Daejacheop' Specimens of Handwriting offers the traces of Gwanam's attempts to engrave gakja at the food of Yigye-gugok. This research was able to ascertain that 'Yigye-gugok Daejacheop' Specimens of Handwriting was a product of Hong Yang-ho's collections maintained under the auspices of the National Central Museum, which are renowned for Song Shi-yeol's penmanship.

A Conceptual Review of the Transaction Costs within a Distribution Channel (유통경로내의 거래비용에 대한 개념적 고찰)

  • Kwon, Young-Sik;Mun, Jang-Sil
    • Journal of Distribution Science
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    • v.10 no.2
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    • pp.29-41
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    • 2012
  • This paper undertakes a conceptual review of transaction cost to broaden the understanding of the transaction cost analysis (TCA) approach. More than 40 years have passed since Coase's fundamental insight that transaction, coordination, and contracting costs must be considered explicitly in explaining the extent of vertical integration. Coase (1937) forced economists to identify previously neglected constraints on the trading process to foster efficient intrafirm, rather than interfirm, transactions. The transaction cost approach to economic organization study regards transactions as the basic units of analysis and holds that understanding transaction cost economy is central to organizational study. The approach applies to determining efficient boundaries, as between firms and markets, and to internal transaction organization, including employment relations design. TCA, developed principally by Oliver Williamson (1975,1979,1981a) blends institutional economics, organizational theory, and contract law. Further progress in transaction costs research awaits the identification of critical dimensions in which transaction costs differ and an examination of the economizing properties of alternative institutional modes for organizing transactions. The crucial investment distinction is: To what degree are transaction-specific (non-marketable) expenses incurred? Unspecialized items pose few hazards, since buyers can turn toalternative sources, and suppliers can sell output intended for one order to other buyers. Non-marketability problems arise when specific parties' identities have important cost-bearing consequences. Transactions of this kind are labeled idiosyncratic. The summarized results of the review are as follows. First, firms' distribution decisions often prompt examination of the make-or-buy question: Should a marketing activity be performed within the organization by company employees or contracted to an external agent? Second, manufacturers introducing an industrial product to a foreign market face a difficult decision. Should the product be marketed primarily by captive agents (the company sales force and distribution division) or independent intermediaries (outside sales agents and distribution)? Third, the authors develop a theoretical extension to the basic transaction cost model by combining insights from various theories with the TCA approach. Fourth, other such extensions are likely required for the general model to be applied to different channel situations. It is naive to assume the basic model appliesacross markedly different channel contexts without modifications and extensions. Although this study contributes to scholastic research, it is limited by several factors. First, the theoretical perspective of TCA has attracted considerable recent interest in the area of marketing channels. The analysis aims to match the properties of efficient governance structures with the attributes of the transaction. Second, empirical evidence about TCA's basic propositions is sketchy. Apart from Anderson's (1985) study of the vertical integration of the selling function and John's (1984) study of opportunism by franchised dealers, virtually no marketing studies involving the constructs implicated in the analysis have been reported. We hope, therefore, that further research will clarify distinctions between the different aspects of specific assets. Another important line of future research is the integration of efficiency-oriented TCA with organizational approaches that emphasize specific assets' conceptual definition and industry structure. Finally, research of transaction costs, uncertainty, opportunism, and switching costs is critical to future study.

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Improved Social Network Analysis Method in SNS (SNS에서의 개선된 소셜 네트워크 분석 방법)

  • Sohn, Jong-Soo;Cho, Soo-Whan;Kwon, Kyung-Lag;Chung, In-Jeong
    • Journal of Intelligence and Information Systems
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    • v.18 no.4
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    • pp.117-127
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    • 2012
  • Due to the recent expansion of the Web 2.0 -based services, along with the widespread of smartphones, online social network services are being popularized among users. Online social network services are the online community services which enable users to communicate each other, share information and expand human relationships. In the social network services, each relation between users is represented by a graph consisting of nodes and links. As the users of online social network services are increasing rapidly, the SNS are actively utilized in enterprise marketing, analysis of social phenomenon and so on. Social Network Analysis (SNA) is the systematic way to analyze social relationships among the members of the social network using the network theory. In general social network theory consists of nodes and arcs, and it is often depicted in a social network diagram. In a social network diagram, nodes represent individual actors within the network and arcs represent relationships between the nodes. With SNA, we can measure relationships among the people such as degree of intimacy, intensity of connection and classification of the groups. Ever since Social Networking Services (SNS) have drawn increasing attention from millions of users, numerous researches have made to analyze their user relationships and messages. There are typical representative SNA methods: degree centrality, betweenness centrality and closeness centrality. In the degree of centrality analysis, the shortest path between nodes is not considered. However, it is used as a crucial factor in betweenness centrality, closeness centrality and other SNA methods. In previous researches in SNA, the computation time was not too expensive since the size of social network was small. Unfortunately, most SNA methods require significant time to process relevant data, and it makes difficult to apply the ever increasing SNS data in social network studies. For instance, if the number of nodes in online social network is n, the maximum number of link in social network is n(n-1)/2. It means that it is too expensive to analyze the social network, for example, if the number of nodes is 10,000 the number of links is 49,995,000. Therefore, we propose a heuristic-based method for finding the shortest path among users in the SNS user graph. Through the shortest path finding method, we will show how efficient our proposed approach may be by conducting betweenness centrality analysis and closeness centrality analysis, both of which are widely used in social network studies. Moreover, we devised an enhanced method with addition of best-first-search method and preprocessing step for the reduction of computation time and rapid search of the shortest paths in a huge size of online social network. Best-first-search method finds the shortest path heuristically, which generalizes human experiences. As large number of links is shared by only a few nodes in online social networks, most nods have relatively few connections. As a result, a node with multiple connections functions as a hub node. When searching for a particular node, looking for users with numerous links instead of searching all users indiscriminately has a better chance of finding the desired node more quickly. In this paper, we employ the degree of user node vn as heuristic evaluation function in a graph G = (N, E), where N is a set of vertices, and E is a set of links between two different nodes. As the heuristic evaluation function is used, the worst case could happen when the target node is situated in the bottom of skewed tree. In order to remove such a target node, the preprocessing step is conducted. Next, we find the shortest path between two nodes in social network efficiently and then analyze the social network. For the verification of the proposed method, we crawled 160,000 people from online and then constructed social network. Then we compared with previous methods, which are best-first-search and breath-first-search, in time for searching and analyzing. The suggested method takes 240 seconds to search nodes where breath-first-search based method takes 1,781 seconds (7.4 times faster). Moreover, for social network analysis, the suggested method is 6.8 times and 1.8 times faster than betweenness centrality analysis and closeness centrality analysis, respectively. The proposed method in this paper shows the possibility to analyze a large size of social network with the better performance in time. As a result, our method would improve the efficiency of social network analysis, making it particularly useful in studying social trends or phenomena.

Smart Store in Smart City: The Development of Smart Trade Area Analysis System Based on Consumer Sentiments (Smart Store in Smart City: 소비자 감성기반 상권분석 시스템 개발)

  • Yoo, In-Jin;Seo, Bong-Goon;Park, Do-Hyung
    • Journal of Intelligence and Information Systems
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    • v.24 no.1
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    • pp.25-52
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    • 2018
  • This study performs social network analysis based on consumer sentiment related to a location in Seoul using data reflecting consumers' web search activities and emotional evaluations associated with commerce. The study focuses on large commercial districts in Seoul. In addition, to consider their various aspects, social network indexes were combined with the trading area's public data to verify factors affecting the area's sales. According to R square's change, We can see that the model has a little high R square value even though it includes only the district's public data represented by static data. However, the present study confirmed that the R square of the model combined with the network index derived from the social network analysis was even improved much more. A regression analysis of the trading area's public data showed that the five factors of 'number of market district,' 'residential area per person,' 'satisfaction of residential environment,' 'rate of change of trade,' and 'survival rate over 3 years' among twenty two variables. The study confirmed a significant influence on the sales of the trading area. According to the results, 'residential area per person' has the highest standardized beta value. Therefore, 'residential area per person' has the strongest influence on commercial sales. In addition, 'residential area per person,' 'number of market district,' and 'survival rate over 3 years' were found to have positive effects on the sales of all trading area. Thus, as the number of market districts in the trading area increases, residential area per person increases, and as the survival rate over 3 years of each store in the trading area increases, sales increase. On the other hand, 'satisfaction of residential environment' and 'rate of change of trade' were found to have a negative effect on sales. In the case of 'satisfaction of residential environment,' sales increase when the satisfaction level is low. Therefore, as consumer dissatisfaction with the residential environment increases, sales increase. The 'rate of change of trade' shows that sales increase with the decreasing acceleration of transaction frequency. According to the social network analysis, of the 25 regional trading areas in Seoul, Yangcheon-gu has the highest degree of connection. In other words, it has common sentiments with many other trading areas. On the other hand, Nowon-gu and Jungrang-gu have the lowest degree of connection. In other words, they have relatively distinct sentiments from other trading areas. The social network indexes used in the combination model are 'density of ego network,' 'degree centrality,' 'closeness centrality,' 'betweenness centrality,' and 'eigenvector centrality.' The combined model analysis confirmed that the degree centrality and eigenvector centrality of the social network index have a significant influence on sales and the highest influence in the model. 'Degree centrality' has a negative effect on the sales of the districts. This implies that sales decrease when holding various sentiments of other trading area, which conflicts with general social myths. However, this result can be interpreted to mean that if a trading area has low 'degree centrality,' it delivers unique and special sentiments to consumers. The findings of this study can also be interpreted to mean that sales can be increased if the trading area increases consumer recognition by forming a unique sentiment and city atmosphere that distinguish it from other trading areas. On the other hand, 'eigenvector centrality' has the greatest effect on sales in the combined model. In addition, the results confirmed a positive effect on sales. This finding shows that sales increase when a trading area is connected to others with stronger centrality than when it has common sentiments with others. This study can be used as an empirical basis for establishing and implementing a city and trading area strategy plan considering consumers' desired sentiments. In addition, we expect to provide entrepreneurs and potential entrepreneurs entering the trading area with sentiments possessed by those in the trading area and directions into the trading area considering the district-sentiment structure.

A Study on Market Expansion Strategy via Two-Stage Customer Pre-segmentation Based on Customer Innovativeness and Value Orientation (고객혁신성과 가치지향성 기반의 2단계 사전 고객세분화를 통한 시장 확산 전략)

  • Heo, Tae-Young;Yoo, Young-Sang;Kim, Young-Myoung
    • Journal of Korea Technology Innovation Society
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    • v.10 no.1
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    • pp.73-97
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    • 2007
  • R&D into future technologies should be conducted in conjunction with technological innovation strategies that are linked to corporate survival within a framework of information and knowledge-based competitiveness. As such, future technology strategies should be ensured through open R&D organizations. The development of future technologies should not be conducted simply on the basis of future forecasts, but should take into account customer needs in advance and reflect them in the development of the future technologies or services. This research aims to select as segmentation variables the customers' attitude towards accepting future telecommunication technologies and their value orientation in their everyday life, as these factors wilt have the greatest effect on the demand for future telecommunication services and thus segment the future telecom service market. Likewise, such research seeks to segment the market from the stage of technology R&D activities and employ the results to formulate technology development strategies. Based on the customer attitude towards accepting new technologies, two groups were induced, and a hierarchical customer segmentation model was provided to conduct secondary segmentation of the two groups on the basis of their respective customer value orientation. A survey was conducted in June 2006 on 800 consumers aged 15 to 69, residing in Seoul and five other major South Korean cities, through one-on-one interviews. The samples were divided into two sub-groups according to their level of acceptance of new technology; a sub-group demonstrating a high level of technology acceptance (39.4%) and another sub-group with a comparatively lower level of technology acceptance (60.6%). These two sub-groups were further divided each into 5 smaller sub-groups (10 total smaller sub-groups) through two rounds of segmentation. The ten sub-groups were then analyzed in their detailed characteristics, including general demographic characteristics, usage patterns in existing telecom services such as mobile service, broadband internet and wireless internet and the status of ownership of a computing or information device and the desire or intention to purchase one. Through these steps, we were able to statistically prove that each of these 10 sub-groups responded to telecom services as independent markets. We found that each segmented group responds as an independent individual market. Through correspondence analysis, the target segmentation groups were positioned in such a way as to facilitate the entry of future telecommunication services into the market, as well as their diffusion and transferability.

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Individualized Determination of Lower Margin in Pelvic Radiation Field after Low Anterior Resection for Rectal Cancer Resulted in Equivalent Local Control and Radiation Volume Reduction Compared with Traditional Method (하전방 절제술을 시행한 직장암 환자에서 방사선조사 영역 하연의 개별화)

  • Park Suk Won;Ahn Yong Chan;Huh Seung Jae;Chun Ho Kyung;Kang Won Ki;Kim Dae Yong;Lim Do Hoon;Noh Young Ju;Lee Jung Eun
    • Radiation Oncology Journal
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    • v.18 no.3
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    • pp.194-199
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    • 2000
  • Purpose : Then determining the lower margin of post-operative pelvic radiation therapy field according to the traditional method (recommended by Gunderson), the organs located in the low pelvic cavity and the perineum are vulnerable to unnecessary radiation. This study evaluated the effect of individualized determination of the lower margin at 2 cm to 3 cm below the anastomotic site on the failure patterns. Materials and Methods . Authors included ぉ patients with modified Astler-Coiler (MAC) stages from B2 through C3, who received low anterior resection and post-operative pelvic radiation therapy from Sept. 1994 to May 1998 at Samsung Medical Center, Sungkyunkwan University. The numbers of male and female patients were 44 and 44, and the median age was 57 years (range: 32-81 years). Three field technique (posterior-anterior and bilateral portals) by 6, 10, 15 MV X-rays was used to deliver 4,500 cGy to the whole pelvis followed by Sn cGy's small field boost to the tumor bed over 5.5 weeks. Sixteen patients received radiation therapy by traditional field margin determination, and the lower margin was set either at the low margin of the obturator foramen or at 2 cm to 3 cm below the anastomotic site, whichever is lower. In 72 patients, the lower margin was set at 2 cm to 3 cm below the anastomotic site, irrespectively of the obturator foramen, by which the reduction of radiation volume was possible in 55 patients ($76\%$). Authors evaluated and compared survival, local control, and disease-free survival rates of these two groups. Results : The median follow-up period was 27 months (range : 7-58 months). MAC stages B2 in 32($36\%$), B3 in 2 ($2\%$), Cl in 2 ($2\%$), C2 in 50 ($57\%$), and C3 in 2 ($2\%$) Patients, respectively. The entire patients' overall survival rates at 2 and 4 years were $94\%$ and $68\%$, respectively, and disease-free survival rates at 2 and 4 years were $86\%$ and $58\%$, respectively. The first failure sites were local only in 4, distant only in 14, and combined local and distant in 1 patient, respectively. There was no significant difference with respect to local control and disease-free survival rates ( p=0.42, p=0.68) between two groups of different lower margin determination policies. Conclusion : The new concept in the individualized determination of the lower margin depending on the anastomotic site has led to the equivalent local control and disease-free survival rates, and is expected to contribute to the reduction of unnecessary radiation-related morbidity by reduction of radiation volume, compared with the traditional method of lower margin determination.

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