• Title/Summary/Keyword: History taking

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A Study of the Change of Breast Uptake in Menstrual Cycle on $^{18}F$-FDG PET/CT (월경 주기에 따른 $^{18}F$-FDG PET/CT에서의 유방 섭취 변화에 관한 고찰)

  • Park, Min-Soo;Park, Hoon-Hee;Kim, Jung-Yul;Lim, Han-Sang;Kim, Jae-Sam;Lee, Chang-Ho
    • The Korean Journal of Nuclear Medicine Technology
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    • v.15 no.1
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    • pp.39-44
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    • 2011
  • Purpose: $^{18}F$-FDG PET/CT has been known a useful modality to diagnose high-glucose-using cells such as cancer cells by glucose metabolism of FDG. Mainly, FDG takes on cancer and inflammatory cells; However, There have been FDG uptakes on normal tissues by individual physiological characteristics, occasionally. Especially, in fertile females, unusual FDG uptake of breast changes as the menstrual cycle, and disturb diagnosis. Therefore, the study aimed to evaluate the change of breast FDG uptake in menstrual cycle on $^{18}F$-FDG PET/CT. Materials and Methods: 160 females ($34{\pm}3.5$ years old) who do not undergo a gynecologic anamnesis and have regular menstrual cycle over the previous 6 months were examined, from March 2009 to February 2010. They were divided 4 groups (each 40 patients) as flow phase, proliferative phase, ovulatory phase and secretory phase using Pregnancy Calculator 0.14. and history taking. Discovery Ste (GE Healthcare, Milwaukee, Mi, USA) was used as PET/CT. We analyzed SUVs on accumulated region on breast, and 3 nuclear medicine specialists did the Blind test. Results: SUVs on the Breast were flow phase ($1.64{\pm}0.25$), proliferative phase ($0.93{\pm}0.28$), ovulatory phase ($1.66{\pm}0.26$) and secretory phase ($1.77{\pm}0.28$). It showed high uptake value in secretory, flow phase and ovulatory phase (p<0.05). In gross analysis, the accumulation of breast was divided into 3 grades as comparing with lung and liver. The breast's uptake was equal to lung (Grade I); between lung and liver (Grade II); equal to or greater than liver (Grade III). The results showed high uptake value in secretory, flow phase and ovulatory phase (p<0.05). Conclusion: In fertile females, FDG uptake of breast changed as menstrual cycle, and it available to diagnose breast disease. Therefore, we consider reducing false-negative finding of breast disease, by doing examination on appropriate period through history taking about individual menstrual cycle.

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A Brief Study on the characteristics of Image-Meaning theory focused on image in the early days of the Joseon Dynasty and SongMing period (송명역학과 조선전기역학의 상수위주적 상의관의 특징)

  • YOON, SEOKMIN
    • The Journal of Korean Philosophical History
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    • no.43
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    • pp.267-293
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    • 2014
  • This paper is aimed at analyzing the characteristics of Image-Meaning theory focused on image in the early days of the Joseon Dynasty and SongMing period. Zhouyi' theory in the early days of the Joseon Dynasty was constructed on the basis of Zhouyi' theory of SongMing period. The characteristics of Image-Meaning theory in the early days of the Joseon Dynasty can be explained largely by two routes. One is the perspective of critical succession on Zhouyi'theory of focusing on meaning that led Chengyi(程?) and Yangwanli(楊萬裏). As the representative of this route, Gwongeun and Toegye not only asserted Image-meaning theory focused on meaning, but also developed a perspective of taking all the image and meaning. The other is the active succession and creative transformation about Image-Meaning theory of Tushuxue that led Chentuan(陳?) and Shaoyong(邵雍). As the representative of that route, Yulgok and Yeohun explained the schematic diagram of the universe of the universe by using methodology of Tushuxue. Furthermore, they actively succeed Shaoyong' Zhouyi theory to expand Image-Meaning theory focused on number. In addition, Cho, Haoyi(曺好益)described the propositions - "meaning is not out of image area, image equipped with meaning all, then there is no law of limitation in image adopted theory. Those propositions are opposed to Chengyi(程?) and Zhuxi(朱熹)' ZhouYi' theory.

The Theory of Chen tuan's Internal Alchemy and Intermixture of Taoism, Buddhism and Neo-Confucianism (진단의 내단이론과 삼교회통론)

  • Kim, Kyeong-Soo
    • The Journal of Korean Philosophical History
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    • no.31
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    • pp.53-86
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    • 2011
  • Taoism exercised its influence and has made much progress apparently under the aegis of the Tang dynasty. But since the external alchemy, a traditional way of eternal life that they have pursued, met the limitation, they were placed in a situation where they needed to seek a new discipline. From this period to the early North Song dynasty, three religions have established the unique theoretical systems of their own theory of ascetic practices. They showed their own unique formats as follows. Neo-Confucianism established the theory of moral training, Buddhism did the theory of ascetic practices and Taoism had theory of discipline. By this time, a person who claimed the Intermixture of Three Religions composed the new system of theory of ascetic practice by taking advantage of other religions and putting them into his own view. Chen tuan established the theory of internal alchemy of Taoism and was the most influential figure in the world of thought since North Song dynasty. He clearly declared that he accepted the merits of other religions in his theory. He added I Ching of Confucianism in I Ching of secret of Taoism to stop the logical gaps during the process of disciplines in Taoism and took ascetic practices on mind of Buddhism into his system while he sought a way to integrate the dual structure of body and mind. The theory of Chen tuan's internal alchemy was training schema with stages of 'YeonJeongHwaGi', 'YeonGiHwaSin', and 'YeonSinHwanHeo' based on the concepts of vital, energy and spirit. The internal alchemy practice that Chen tuan was saying started from the practice of Zen to keep the mind calm with the basis of fundamental principles of interpretation of book of change according to Taoism. When a person reached the state to be in concert with all changes at the end of the silence and be full of wisdoms, he finally returned to the state of BokGwiMuGeuk by taking the flow of subtle mind and transforming it into energy. He expressed this process by drawing 'MuGeukDo'. Oriental philosophy categorized human into 'phenomenal existence' and 'original existence'. The logic of theory of ascetic practice has been established from these 'category of existence'. It would be determined whether it will return to 'original existence' or be stepped up from 'phenomenal existence' according to how the concept of 'self' or 'I' was made. Chen tuan who established the theory of internal alchemy in Taoism has established the unique theory of internal alchemy discipline and system of intermixture of three religions in this aspect. Today is called 'era of self-loss' or 'era of incurable diseases' caused by environmental pollution. It's still meaningful to review the theory of discipline of Chen tuan's connecting the body and the soul to heal the self, and keep life healthy and pursue the new way of discipline based on it.

Life History of Bothriocephalus opsariichthydis(Cestoda ; Pseudophyllidea) Parasitic in Common Carp, Cyprinus carpio (Linne) (잉어에 기생한 촌충, Bothriocephalus opsariichthydis의 생활사에 관한 연구)

  • KIM Jong-Yeon;CHUN Seh-Kyu;KIM Young-Gill;PARK Sung Woo
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.19 no.2
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    • pp.155-168
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    • 1986
  • In Korea, lots of Israeli carp (Cyprinus carpio) are cultured by means of net cages in dams and lakes, but many carp have been subjected to heavy infestation of the cestoid, Bothriocephalus opsariichthydis. Nevertheless the parasitic state and life history of the cestoid are not yet reported. This reason led the author to study the parasitic state and life history of B. opsariichthydis parasitized in the carp in order to take effective control measures against its damage. Israeli carp were sampled from two fish farms, in Taech'on and Kyongch'on. After dissection of the specimens, the cestoid were obtained and the parasitic rates were examined. After taking the eggs from adult worms, the development of the eggs were observed. Coracidia were exposed to four kinds of crustaceans in order to investigate the infection rate and development of the larva. Finally, tile development of the larva in the final host was investigated. The fully mature eggs were in the cleavage stage, when they are released, and the size ranged 47.5 to 55.0 $(50.9){\times}30.0$ to 32.5 (31.1) um, in the state of under-developed coracidia and blastomeres. The parasitic rate of the cestoid in Israeli carp from Taechon was $55.5\%$ in 1984 and $21.6\%$ in 1985, that from Kyongchon was $64.7\%$ in 1984, and color carp from Kusan was $14.9\%$ in 1984. The eggs were hatched to coracidia within 48 hours under 26 to $28^{\circ}C$. The cestoid showed a strong affinity to Thermocyclops hyalinus and Paracyclops fimbriatus and the infection rates were $93.5\%$ and $75.5\%$, respectively. At 14 days after the infection to Thermocyclops hyalinus and Paracyclops fimbriatus, the larvae of the cestoid grew into fully developed procercoids; 207 to $226 (214){\times}90$ to 102 (94) um in size. Sixty days after carp have ingested the Thermocyclops hyalinus infected with the fully developed procercoids, the larvae of the cestoid matured into adult worms in the intestines of the carp.

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Context Prediction Using Right and Wrong Patterns to Improve Sequential Matching Performance for More Accurate Dynamic Context-Aware Recommendation (보다 정확한 동적 상황인식 추천을 위해 정확 및 오류 패턴을 활용하여 순차적 매칭 성능이 개선된 상황 예측 방법)

  • Kwon, Oh-Byung
    • Asia pacific journal of information systems
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    • v.19 no.3
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    • pp.51-67
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    • 2009
  • Developing an agile recommender system for nomadic users has been regarded as a promising application in mobile and ubiquitous settings. To increase the quality of personalized recommendation in terms of accuracy and elapsed time, estimating future context of the user in a correct way is highly crucial. Traditionally, time series analysis and Makovian process have been adopted for such forecasting. However, these methods are not adequate in predicting context data, only because most of context data are represented as nominal scale. To resolve these limitations, the alignment-prediction algorithm has been suggested for context prediction, especially for future context from the low-level context. Recently, an ontological approach has been proposed for guided context prediction without context history. However, due to variety of context information, acquiring sufficient context prediction knowledge a priori is not easy in most of service domains. Hence, the purpose of this paper is to propose a novel context prediction methodology, which does not require a priori knowledge, and to increase accuracy and decrease elapsed time for service response. To do so, we have newly developed pattern-based context prediction approach. First of ail, a set of individual rules is derived from each context attribute using context history. Then a pattern consisted of results from reasoning individual rules, is developed for pattern learning. If at least one context property matches, say R, then regard the pattern as right. If the pattern is new, add right pattern, set the value of mismatched properties = 0, freq = 1 and w(R, 1). Otherwise, increase the frequency of the matched right pattern by 1 and then set w(R,freq). After finishing training, if the frequency is greater than a threshold value, then save the right pattern in knowledge base. On the other hand, if at least one context property matches, say W, then regard the pattern as wrong. If the pattern is new, modify the result into wrong answer, add right pattern, and set frequency to 1 and w(W, 1). Or, increase the matched wrong pattern's frequency by 1 and then set w(W, freq). After finishing training, if the frequency value is greater than a threshold level, then save the wrong pattern on the knowledge basis. Then, context prediction is performed with combinatorial rules as follows: first, identify current context. Second, find matched patterns from right patterns. If there is no pattern matched, then find a matching pattern from wrong patterns. If a matching pattern is not found, then choose one context property whose predictability is higher than that of any other properties. To show the feasibility of the methodology proposed in this paper, we collected actual context history from the travelers who had visited the largest amusement park in Korea. As a result, 400 context records were collected in 2009. Then we randomly selected 70% of the records as training data. The rest were selected as testing data. To examine the performance of the methodology, prediction accuracy and elapsed time were chosen as measures. We compared the performance with case-based reasoning and voting methods. Through a simulation test, we conclude that our methodology is clearly better than CBR and voting methods in terms of accuracy and elapsed time. This shows that the methodology is relatively valid and scalable. As a second round of the experiment, we compared a full model to a partial model. A full model indicates that right and wrong patterns are used for reasoning the future context. On the other hand, a partial model means that the reasoning is performed only with right patterns, which is generally adopted in the legacy alignment-prediction method. It turned out that a full model is better than a partial model in terms of the accuracy while partial model is better when considering elapsed time. As a last experiment, we took into our consideration potential privacy problems that might arise among the users. To mediate such concern, we excluded such context properties as date of tour and user profiles such as gender and age. The outcome shows that preserving privacy is endurable. Contributions of this paper are as follows: First, academically, we have improved sequential matching methods to predict accuracy and service time by considering individual rules of each context property and learning from wrong patterns. Second, the proposed method is found to be quite effective for privacy preserving applications, which are frequently required by B2C context-aware services; the privacy preserving system applying the proposed method successfully can also decrease elapsed time. Hence, the method is very practical in establishing privacy preserving context-aware services. Our future research issues taking into account some limitations in this paper can be summarized as follows. First, user acceptance or usability will be tested with actual users in order to prove the value of the prototype system. Second, we will apply the proposed method to more general application domains as this paper focused on tourism in amusement park.

A Documentational Study on the Development of Chi-Kung-Hak (기공학(氣功學) 발달(發達)에 관한 문헌적(文獻的) 연구(硏究))

  • Kim, Woo Ho;Hong, Won Sik
    • Journal of Korean Medical classics
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    • v.4
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    • pp.19-73
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    • 1990
  • Today, many people are more interested in preventing the disease than curing it. Chi-Kung (氣功) is the way of Life-Cultivation (養生法) peculiar to the orient, it is reported in china that Chi-Kung has an excellent curative value not only in curing the disease but also in preventing it. But the full-scale study of Chi-Kung is not be made up to now in Korea, so I studied the developmental history of chinese Chi-Kung through the oriental medical books. From this study, I reached the following conclusions ; 1. Chi-Kung is naturally derived from the self-preservation instinct to adapt oneself to circumstances of the nature, but in the investigation from the documentational records, it is originated in the treatment method of the Sam-Huang-O-Jae (三皇五帝 )period to cure the abnormal circulation of the vital force and blood caused by damp (濕). 2. As the principle and the method of the Life-Cultivation of the Chun-chu-Jeon-Kook (春秋戰國) periods were recorded in Huang-Jae-Nai-Gyung (黃帝內徑) detailly and the remedy examples by ancient Chi-Kung such as Tao-Yin (導引), Haeng-Chi (行氣) were presented, we considered that theoretical basis of the development of Life-cultivation and Chi-Kung study was furnished in that period. 3. A famous doctor, Hwa-Ta (華陀) lived in Han dynasty, researched the theory and practice of Tao-Yin transmitted from the former generations, as that result, he formed a kind of medical gymnastics what is called O-Keum-Hi (五禽戱). It is considered that 'O-Keum-Hi' is a Tao-Yin method developed more practically and systemetically than the Tao-Yin appeared in the 'Jang-Ja' (莊子) or 'Hoy-Nam-Ja' (淮南子). 4. In Wui-Jin-Nambook Jo (魏晋南北朝) periods, the contents of Chi-Kung were more abundant under the influence of Buddhism (佛敎) and Taoism (道敎). Galhong (葛洪), the author of 'Po-Bak-Ja' (抱朴子) arranged the ancient Chi-Kung method systematically first of all, Tao-Goeng-Gyung (陶宏景), the author of 'Yang-Seong-Yeun-Myung-Rok' (養性延命錄) recorded the 'Yook-Ja-Geul' (六字訣) first time. 5. There is a new development of Chi-Kung therapy in Soo-Tang-Odae (隋唐五代) pefiods, especially So-Won-Bang (巢元方), the author of 'Jey-Byung-Won-Hwu-Ron' (諸病源候論) collected aimost all of the Chi-Kung method, for curing the disease formed before soo (隋) period. From that fact, we supposed that Chi-Kung was utilized more widely in curing the disease. 6. 'So-Ju-Cheon-Hwa-Hu-Peob' (小周天火候法) was adopted as the best orthodox approach under the influence of Nae-Tan-Taoist (道敎內丹學派) in Song-Keum-Won (宋金元) periods, especially in the song dynasty, 'Pal-Dan-Geum' (八段錦) was appeared and assignment of six-Chi (六氣) for bowel and viscera in the 'Yook-Ja-Geul' (六字訣) was decided firmly, that is to say Lung-Si (肺-呬), Heart-Kha (心-呵), Spleen-Hoa (脾-呼), Liver-Hoe (肝-噓), Kidneychui (賢-吹), Three-Burner-shi (三焦-嘻). 7. In Myung-Cheong (明淸) periods, The general practitioner applied the principle of 'Byun-Jeng-Ron-Chi' (辨證論治) to the Chi-Kung field, and after Myeong dynasty the style of doing 'Yook-Ja-Gyel' (六字訣) was developed to the moving style. 8. Today, in china, the study on the Chi-Kung is being progressed constantly under the positive assistance of government, Chi-Kung-Hak (氣功學) has taking its place as a branch of study step by step. It is considered that the establishment of Chi-Kung-Hak Classroom (氣功學教室) and Medical Chi-Kung Center (氣功療法室) for special and systematic research are needed, at the same time the settlement of institutional system for training the Chi-Kung technician (氣功師) is also needed.

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The Memorial Park Planning of 5·18 Historic Sites - For Gwangju Hospital of Korea Army and 505 Security Forces - (5·18 사적지 기념공원화 계획 - 국군광주병원과 505보안부대 옛터를 대상으로 -)

  • Lee, Jeong-Hee;Yun, Young-Jo
    • Journal of the Korean Institute of Landscape Architecture
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    • v.47 no.5
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    • pp.14-27
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    • 2019
  • This study presents a plan for a memorial park that respects the characteristics based on the historical facts for the concept of space of the Gwangju Hospital of Korea Army and the location of the 505 Security Forces, which were designated as historic sites after the 5-18 Democratization Movement. The Gwangju Metropolitan City as it is the location of the 5-18 historic sites, is taking part in the 5-18 Memorial Project, and plans to establish a city park recognizing the historic site of the 5-18 Democratization Movement, which has been preserved only as a memory space to this point. The park is promoting a phased development plan. This study suggests that the 5-18 historic sites can be modernized and that social consensus can establish the framework of the step-by-step planning and composition process to ensure the plans for the space heals wounds while preserving the history. In this paper, we propose a solution to a problem. We solve the approach for space utilization through an analysis of precedent research and planning cases related to park planning at historical sites. In addition to exploring the value of the site, we also describe the space utilization strategy that covers the historical characteristics and facts while maintaining the concept of park planning. As a result of the research, the historic site of the Gwangju Hospital of Korea Army is planned as a park of historical memory and healing in order to solve the problems left behind by the 5-18 Democratization Movement. The historic site of the 505 Security Forces was selected as an area for historical experiences and a place for learning that can be sympathized with by future generations of children and adolescents in terms of expanding and sustaining the memory of the 5-18 Democratization Movement. In the planning stage, the historical sites suggested the direction of space utilization for representation as did the social consensus of citizens, related groups, and specialists. Through this study, we will contribute to construction of a memorial park containing historical values in from 5-18 historic sites. It is meaningful to suggest a direction that can revitalize the life of the city as well as its citizen and can share with the history with future generations beyond being a place to heal wounds and keep alive the memory of the past.

The Critic on Mohism in the History of Korean Thoughts Centered on the Theory of Rejecting Heterodoxy (한국사상사에서의 묵가(墨家) 비판 - 벽리단론(闢異端論)의 전개 양상을 중심으로 -)

  • Yun, Muhak
    • The Journal of Korean Philosophical History
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    • no.29
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    • pp.89-123
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    • 2010
  • As above, as theoretical basis of critiques against School of Mohism, the researcher summarized the positions of the elder Confucian scholars including Meng Zi. In the body of text, taking it as promises, the researcher examined the critiques against Mo Tzu and School of Mohism as well focusing on the aspects and development of the theory of rejecting heterodoxy which had been introduced and strongly argued from the end of Goryeo kingdom to the late Joseon period. The summary of the body of this text is as follows: In the old literatures prior to Goryeo Kingdom, the researcher couldn't find any cases that either the School of Mohism or Mo Tzu including the Hundred Schools of Thought had been rejected explicitly. Having reached the end of Goryeo and the beginning of Joseon period, Meng Zi's viewpoints on the theory of rejecting heterodoxy had begun to emerge and come into play with the progress of accepting Neo-Confucianism, and, these critiques against Yang Zhu and Mo Tzu being given, the scholar-literati circle had started rejecting Buddhism and Lao Tzu. Basically the contents of the critiques against the School of Mohism in the early period of Joseon were in succession to Meng Zi's theory of rejecting heterodoxy and the views and thoughts of the elder Confucian scholars including Han Yu rather than any specific critiques against Mo Tzu' ideology itself. Until entering the middle of Joseon period, the critiques against the School of Mohism had been used as a tool to promote Confucianism in an affirmative manner, while arguing strongly against the viewpoint of Han Yu in the first place. Particularly, not only the original text of the Mo Tzu's writings were directly quoted, although it was partial, but also the contents of the critiques against the School of Mohism had been developed and stretched to the extent of their entire ideological system. Having approached to the late period of Joseon, the critiques against the School of Mohism had begun to be linked to those critiques against the study of state examination or of sentence patterns including Catholic Church, furthermore the critics raised their harsh tones against the irregularities of the society at large like the issue of corruptions of the government officials of those days instead, although they still had firmly stood on the ground of the theory of rejecting heterodoxy. Those scholars that belonged to the School of Practical Learning, in particular, said in justification of the School of Mohism arguing that the major ideologies of Mo Zi had usefulness in the real world, also they even evaluated that Meng Zi ' critiques against the School of Mohism were immoderate. To sum up, characteristics of scholars in the Joseon period to understand and critique the School of Mohism are that ideologies of Mo Tzu were mostly used as a tool for the sake of critiques against heresies in other sectors of society based mainly on Meng Zi's theory of rejecting heterodoxy, rather than opposing views against the ideologies or philosophies of the School of Mohism itself. Meanwhile, however, on the plus side, the critics praised Mo Tzu's individual efforts in order to put his ideology of peace into practice apart from the ideological system of the School of Mohism. Also, having reached the late period of Joseon, the researcher was able to have discovered the fact that the writings of Mo Tzu had been used as historical materials in order to ascertain historical truths of Confucian Scriptures, rather not having it regarded as an ideology text.

The Study of Korean-style Leadership (The Great Cause?Oriented and Confidence-Oriented Leadership) (대의와 신뢰 중시의 한국형 리더십 연구)

  • Park, sang ree
    • The Journal of Korean Philosophical History
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    • no.23
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    • pp.99-128
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    • 2008
  • This research analyzes some Korean historical figures and presents the core values of their leaderships so that we can bring up the theory of leadership which would be compatible with the current circumstances around Korea. Through this work, we expected that we would not only find out typical examples among historical leaders but also reaffirm our identities in our history. As a result of the research, it was possible to classify some figures in history into several patterns and discover their archetypal qualities. Those qualities were 'transform(實事)', 'challenge(決死)', 'energize(風流)', 'create(創案)', and 'envision(開新)' respectively. Among the qualities, this research concentrated on the quality of 'challenge', exclusively 'death-defying spirit'. This spirit is the one with which historical leaders could sacrifice their lives for their great causes. This research selected twelve figures as incarnations of death-defying spirit, who are Gyebaek(階伯), Ganggamchan(姜邯贊), Euljimundeok(乙支文德), Choeyoung(崔瑩),ChungMongju(鄭夢周), Seongsammun (成三問), Yisunsin(李舜臣), Gwakjaewoo(郭再祐), Choeikhyeon(崔益鉉), Anjunggeun(安重根), Yunbonggil(尹奉吉), Yijun(李儁). Through analyzing their core values and abilities and categorizing some historical cases into four spheres such as a private sphere, relations sphere, a community sphere, and a society sphere, we came to find a certain element in common among those figures. It was that they eventually took the lead by showing the goal and the ideal to their people at all times. Moreover, their goals were always not only obvious but also unwavering. In the second chapter, I described the core value in a private sphere, so called '志靑靑'. It implies that a leader should set his ultimate goal and then try to attain it with an unyielding will. Obvious self-confidence and unfailing self-creed are core values in a private sphere. In the third chapter, I described the core value in a relative sphere, the relationship between one and others. It is '守信結義'. It indicates that a leader should win confidence from others by discharging his duties in the relation with others. Confidence is the highest leveled affection to others. Thus, mutual reliance should be based on truthful sincerity and affection toward others. Stubbornness and strictness are needed not to be prompted by pity simultaneously. In the fourth chapter, I described the core value in a community sphere. It is '丹心合力'. For this value, what are required to a leader are both his community spirit and his loyalty to one's community. Moreover, the strong sense of responsibility and the attitude of taking an initiative among others are also required. Thus, it can be said that the great power to conduct the community is so called fine teamwork. What's more, the attitude of the leader can exert a great influence on his community. In the fifth chapter, I described the core value of death defying spirit in the society sphere. This value might be more definite and explicit than other ones described above. A leader should prepare willingly for one's death to fulfill his great duties. 'What to do' is more important for a leader than 'how to do'. That is to say, a leader should always do righteous things. Efficiency is nothing but one of his interests. A leader must be the one who behaves himself always according to righteousness. Unless a leader's behaviors are based on righteousness, it is absolutely impossible that a leader exerts his leadership toward people very efficiently. Thus, it can be said that a true leader is the one not only who is of morality and but also who tries to fulfill his duties.

Effect of Ultraviolet-B Radiation Acclimation to Fresh Water Daphnia magna Simultaneously Exposed to Several Heavy Metals and UV-B Radiation (담수 물벼룩 Daphnia magna의 자외선 B 적응이 자외선과 중금속의 동시노출에 따른 독성반응에 미치는 영향)

  • Kim, Jung-Kon;Lee, Min-Jung;Oh, So-Rin;Choi, Kyung-Ho
    • Journal of Environmental Health Sciences
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    • v.33 no.2 s.95
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    • pp.123-131
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    • 2007
  • Many environmental contaminants including several metals, polycyclic aromatic hydrocarbons, and pharmaceuticals, have been identified to be phototoxic in the water environment. Concerns regarding photo-enhancement of toxicity of several environmental contaminants have been increasing because of the increased level of ultraviolet irradiation on the earth surface. However, there exist arguments that there might be certain defense mechanisms taking place in the aquatic ecosystem, which may include behavioral characteristics or genetic acclimation. This study was conducted to understand the potential responses of aquatic receptors to several phototoxic metals in the real environment, where long-term acclimation of such organisms to low dose UV-B may take place. For this purpose, water flea Daphnia magna was acclimated to environmentally relevant dose of UV-B (12 to $18uW/cm^2$) for >11 generations. The differences in developmental and life history characteristics, and toxicity responses were evaluated. Acclimation did not affect the daphnids' growth, longevity, and reproduction characteristics such as time to first brood, and brood size: After 21 d, survival of D. magna was not influenced by UV-B acclimation. When the number of young per female was compared. the daphnids acclimated for 11 generations tend to produce less number of neonates than the un-acclimated individuals but with no statistical significance (p>0.05). Four metals that were reported to be phototoxic elsewhere were employed in this evaluation, that include As, Cd. Cu, and Ni. UV-B level being applied in acclimation did increase the toxicity of Cd and Cu, significantly (p<0.05). However, the toxicities of As and Ni were not affected by irradiation of UV-B. Phototoxic responses were evaluated between the acclimated and the un-acclimated daphnids. For Cu, UV-B acclimation led to reduction of the photo-induced toxicity $(p\approx0.1)$ in daphnids. Non-acclimated Daphnia were affected by 50% at 4.18 ug/l Cu. but UV-B acclimated individuals exhibited $EC_{50}$ of 5.89 ug/l. With Cd, UV-B acclimation appeared to increase phototoxicity (p>0.05). With As and Ni, UV-B acclimation did not influence photo-induced toxicity. This observation may be in part explained by the type of reactive oxygen species that were generated by each metal. Similar to UV-B light, Cu is known to generate superoxide anion by acting as redox cycling toxicant. This is one of the first studies that employed_laboratory based UV-B acclimated test species for photoenhanced toxicity evaluation.