초기 개체군 밀도가 포식자-피식자 생태계 안정성에 미치는 영향

조정희,이상희,Cho, Jung-Hee,Lee, Sang-Hee 한국시뮬레이션학회 2013 한국시뮬레이션학회 논문지 Vol.22 No.3

생태계는 다양한 환경 내에 다양한 생물종이 서로 상호작용하고 있는 복잡계이다. 이들 상호작용은 계층적 먹이그물 구조를 이루고 있는데, 많은 경우, 포식자-피식자-식물의 관계를 보여준다. 포식자-피식자 경쟁관계는 시공간적으로 일어나는 현상이기 때문에, 초기시점에서의 개체들 분포와 밀도가 어떠한가는 매우 중요한 정보를 담고 있다. 본 연구에서는, 이들 세 단계 계층구조의 생태계를 간단한 격자 모델로 구성하고 이 모델을 사용하여 각 종의 초기 개체군 밀도가 변함에 따라 생태계 안정성이 어떻게 변하는지를 연구하였다. 격자공간은 $L{\times}L$ 크기의 L(=100) 사각격자로 구성되었다. 식물의 초기 밀도는 0.2로 고정하였다. 시뮬레이션 결과는, 포식자의 밀도가 0.4이하, 피식자의 밀도가 0.5이하일 때 두 종이 공존하는 것을 보여 주었으며, 포식자 밀도가 0.5이상, 피식자 밀도가 0.6 이상의 조건에서는 두 종이 멸종하는 것을 보여 주었다. 공존과 멸종의 두 상태가 접하는 영역의 조건에서는 확률적으로 공존하기도하고 멸종하기도 하는 비선형성이 강한 행동을 보여 주었다. 본 연구를 통해 초기종의 밀도가 생태계 안정성에 매우 중요한 역할을 한다는 것을 알 수 있었다. The ecosystem is the complex system consisting of various biotic and abiotic factors and the factors interact with each other in the hierarchical predator-prey relationship. Since the competitive relation spatiotemporally occurs, the initial state of population density and species distribution are likely to play an important role in the stability of the ecosystem. In the present study, we constructed a lattice model to simulate the three-trophic ecosystem (predatorprey- plant) and using the model, explored how the ecosystem stability is affected by the initial density. The size of lattice space was $L{\times}L$, (L=100) with periodic boundary condition. The initial density of the plant was arbitrarily set as the value of 0.2. The simulation result showed that predator and prey coexist when the density of predator is less than or equal to 0.4 and the density of prey is less than or equal to 0.5. On the other hand, when the predator density is more than or equal to 0.5 and the density of prey is more than or equal to 0.6, both of predator and prey were extinct. In addition, we found that the strong nonlinearity in the interaction between species was observed in the border area between the coexistence and extinction in the species density space.

호흡에 따른 간장용적의 변화와 정상조직손상확율에 미치는 영향에 관한 연구

조정희,김주호,이석,박재일,Cho Jung Hee,Kim Joo Ho,Lee Suk,Park Je Il 대한방사선치료학회 2001 大韓放射線治療技術學會誌 Vol.13 No.1

Purpose: The aim of this study is to investigate geometrical and volumetrical changes of liver due to breathing and its impact to NTCP. In order to attain better treatment results it should be considered deliberately during planning session. Mehtods and Materials : Seven patients were examined in this study who have done TACE for accurate tumor margin drawing. After contrast media injection, C-T scan data were obtained in supine position during breathing free, inhalation and exhalation, respectively. For all patients C-T scan were done with same scanning parameters- 5 mm index, 5 mm thickness and pitch 1. Based on C-T data we have measured differences of each variables between breathing status such as changes of total and remained liver volumes, GTV, beam path length and superior to inferior shift. NTCP were calculated using Lyman's effective volume DVH reduction scheme and for this NTCP calculation, the V50 was computed from DVH and each m, n value were referred from Burmans data. Results : The measured total tilter volume and the remained liver volume changed between inspiration and expiration about $1.2-7.7\%(mean+2.7\%)$ and $2.5-13.23\%(mean=5.8\%)$ respectively, and these results were statistically significant(p>0.1). The GTV difference in each patient varied widely from $1.17\%\;to\;30.69\%$, but this result was not statistically significant. Depending on the breathing status, the beam path length was changed from 0.5 cm to 1.1 cm with the average of 0.7 cm, and it was statistically significant(p=0.006). The measured superior to inferior shifts were ranged from 0.5 cm to 3.74 cm. The NTCPs were changed relatively small in each patient, but the variation was large between the patients. The mean NTCP difference was $10.5\%$, with the variation ranged from $7\%\;to\;23.5\%$. Conclusion : Variations of liver volume and of beam path length were changed significantly depending on the breathing statues and the range of variation itself was very different between the patients. Since this variance could seriously affect the clinical outcomes of radiation treatments, the breathing of patients need to be accounted when a final treatment planning is derided.

막분리 기술을 이용한 액체염료 제조에 관한 연구

조정희,이정학 ( Jung Hee Cho,Chung Hak Lee ) 한국공업화학회 1992 공업화학 Vol.3 No.2

염료속에 함유된 무기염(NaCl, Na_2SO_4)의 선택적 제거를 위해 역확산과 역삼투를 결합한 방법과 nanofiltration(NF)을 각각 이용하였다. 역확산에 의한 염의 제거율은 염의 종류에 따라 1회(one pass)에 1∼30%를 나타냈으며 염과 염료의 분리비는 10∼500의 매우 큰 값을 갖는 반면 염료의 손실율은 0.3% 이하 였다. 염료용액을 순환시킬수록 음이온인 Cl^- 이온의 제거율이 증가하고 양이온인 Na^+ 이온의 제거율이 감소하는 도난투석현상이 관찰되었다. 또한 공급용액의 유속이 염의 제거에 미치는 영향을 살펴보았다. 역확산에 의해 염이 제거된 염료를 평판형 역삼투막을 사용하여 농축하였으며 Cl^- 이온의 배제율을 solution-diffusion 모델식에 적용하였다. 2회의 Diafiltration(DF)을 수행한 NF에서도 역확산에서와 마찬가지로 도난투석에 의해 Cl^- 이온의 배제율 감소와 음배제율을 관찰하였다. 특히 두번째 DF에서 도난투석의 효과는 더욱 크게 나타났다. Studies were carried out on the selective removal of inorganic salts such as NaCl and Na_2SO_4 from dye solution, using counter diffusion-reverse osmosis and nanofiltration, respectively. For the dye solution used in the experiments, 1 to 30% of salts were removed by counter diffusion while the loss of dye molecules was less than 0.3%. The separation factors by one pass operation were 10-500 according to ionic species. In five successive operations, removals of anion(Cl^-) increased but those of cation(Na^+) decreased due to the Donnan effect. Effects of feed flow rate on removal efficiencies of various ions were also observed at constant flow rate of stripping water. Reverse osmosis of desalted dye solution by counter diffusion was conducted to prepare highly concentrated liquid dyes. The rejection efficiency of dye molecules was greater than 99%. For the rejection efficiency of chloride ion, experimental values were compared with theoretical ones based on solution-diffusion model. Two stage diafiltration was performed in nanofiltration. The rejection efficiency of chloride ion was continuously decreased due to the Donnan dialysis and even negative rejection was observed. The Donnan effect was more pronounced in the second diafiltration.

상아질 표면처리가 글라스 아이오노머 시멘트의 변연누출에 미치는 영향에 관한 연구

조정희,홍찬의,신동훈,Cho, Jung-Hee,Hong, Chan-Ui,Shin, Dong-Hoon 대한치과보존학회 1992 Restorative Dentistry & Endodontics Vol.17 No.1

The purpose of this study was to evaluate the effect of the dentin pretreatment on the marginal leakage of a glassionomer cement. 1n this study, 60 molars with sound and healthy crown portion were used. The dentin surface of these teeth were exposed and polished with 600 grit silicon carbide paper. Square - shaped cavities were prepared on the flattened dentin surfaces and these were divided into 4 groups according to the dentin pretreatment procedures. Group I : Dentin pretreatment with distilled water as a control group. Group II : Dentin pretreatment with 5% sodium hypochlorite solution. Group III : Dentin pretreatment with Ketac conditioner. Group IV : Dentin pretreatment with 40% polyacrylic acid. The degrees of dye penetration in the cavity walls were assessed using a stereoscope at ${\times}40$ magnification according to the maximum dye penetration. The results were analyzed by using Mann - Whitney U test. The results were as follows : 1. All groups showed varying depth of dye penetration. 2. Distilled water group showed the most severe marginal leakage when compared with the other groups(P<0.05). 3. 40% polyacrylic acid group showed the least amount of marginal leakage compared with the other groups (P<0.05). 4. There were significant differences between Goup I(distilled water) and Group IV (40% polyacrylic acid)(P<0.05), but there were no significant differences among Group I(distilled water), Group II(sodium hypochlorite), Group III(Ketac conditioner) (P>0.05).

노인의 건강관심도와 심뇌혈관질환에 대한 지식 및 건강증진행위와의 관계

조정희,Cho, Jung Hee 한국가정간호학회 2021 가정간호학회지 Vol.28 No.2

Purpose: The purpose of this study was to find out the relationship between health concern, knowledge of cardio-cerebrovascular disease, and health-promoting behaviors among the elderly in the community. Method: The subjects of the study were 142 senior citizens aged 65 years or older in Cheongju-si, Chungcheong-do. Data were collected using structured questionnaires that included questions on the general characteristics, health concerns, knowledge of cardio-cerebrovascular disease, and health-promoting behaviors. The collected data were analyzed by the statistical program SPSS 20.0. The frequencies, percentages, averages, and standard deviations of the collected data were analyzed using a t-test, ANOVA, Mann Whitney U test, and Pearson's correlation coefficient, basing on the purpose of the study. The Scheffe test was carried out as a posteriori test. Result: The elderly were found to have a high health concern, but their knowledge of cardio-cerebrovascular disease was low, and their health-promoting behaviors were above the intermediate level. There was a significant positive correlation between each variable, which means that the higher the health concern was, the more knowledge an individual had of cardio-cerebrovascular disease, and the more health-promoting behaviors one had. Conclusion: This suggests that the elderly in the community should be encouraged to engage in the actions that promote their health by raising their level of health concern and awareness of diseases through health education, basing on their individual characteristics.

호흡에 따른 간장용적의 변화와 정상조직 손상확율에 미치는 영향에 관한 연구

조정희,김주호,이석,박재일,Cho Jung Hee,Kim Joo Ho,Lee Suk,Park Jae Il 대한방사선사협회 2001 대한방사선사협회지 Vol.27 No.2

Ⅰ. Purpose : The aim of this study is to investigate geometrical and volumetrical changes of liver due to breathing and its impact to NTCP. In order to attain better treatment results it should be considered deliberately during planning session. Ⅱ. Method

환경요인과 대서양 청어자원량과의 관계

조정희,Cho, Jung-Hee,Gates, John M. 한국환경경제학회 2001 자원·환경경제연구 Vol.10 No.4

대서양 청어는 바닷가재 어업에 있어 주요 미끼로서 사용되어지고 있고 해양 생태계내에서 다른 어류들의 먹이로서 중요한 위치를 차지하고 있다. 그러나 해양생태계의 환경적인 요소, 즉 해수면 온도, 플랑크톤량, 서식지 해저퇴적물 상태에 따라 자원이 민감하게 영향을 받는다. 특히 미성어의 단계에서는 낮은 해수 온도에 대해 영향을 받기가 쉽다. 이 연구에서는 인공위성을 이용하여 측정된 해수면 온도와 2년생 가입자원의 상관관계를 분석하였다. 해수면 온도의 측정지역은 대서양 청어의 산란지역으로 한정하였다. 연구 결과 상관계수는 0.69로 나타났고 이는 어업자원의 변동성을 설명함에 있어 환경적인 요인이 중요하게 고려되어야 한다는 것을 의미한다.

EPID의 적정관리 도구로서의 유용성에 관한 연구

조정희,방동완,윤성익,박재일,Cho Jung Hee,Bang Dong Wan,Yoon Seong Ik,Park Jae Il 대한방사선치료학회 1999 大韓放射線治療技術學會誌 Vol.11 No.1

Purpose : The aim of this study is to conform the possibility of the liquid type EPID as a QC tools to clinical indication and of replacement of the film dosimetry. Aditional aim is to describe a procedure for the use of a EPID as a physics calibration tool in the measurements of radiation beam parameters which are typically carried out with film. Method & Materials : In this study we used the Clinac 2100c/d with EPID. This system contains 65536 liquid-filled ion chambers arranged in a $256{\times}256$ matrix and the imaging area is $32.5{\times}32.5cm$ with liquid layer thickness of 1mm. The EPID was tested for different field sizes under typical clinical conditions and pixel values were calibrated against dose by producing images using various thickness of lead attenuators(lead step wedge) using 6 & 10MV x-ray. We placed various thickness of lead on the table of linear accelerator and set the portal vision an SDD of 100cm. To acquire portal image we change the field size and energy, and we recorded the average pixel value in a $3{\times}3$ pixel region of interest(ROI) at field center was recorded. The pixel values were also measured for different field sizes in order to evaluate the dependence of pixel value on x-ray energy spectrum and various scatter components. Result : The EPID, as a whole, was useful as a QA tool and dosimetry device. In mechanical check, cross-hair centering was well matched and the error was less than ?2mm and light/radiation field coincidence was less than 1mm also. In portal dosimetry the wider the field size the the higher the pixel value and as the lead thickness increase, the pixel value was exponentially decreased. Conclusions : The EPID was very suitable for QA tools and it can be used to measure exit dose during patients treatment with reasonable accuracy. But when indicate the EPID to clincal study deep consideration required

1980년대 서사극의 현실반영성 연구

조정희(Cho, jung-hee) 부경대학교 인문사회과학연구소 2010 인문사회과학연구 Vol.11 No.1

한국 희곡의 현대성은 1960년대를 중심으로 그 양상이 크게 달라진다. 계속 변화하는 시대가 예술에 대해서도 새로운 요구를 하고 있었고 그것을 표상하기 위해서는 재현양식도 변해야 했다. 시대적 상황과 그 사회 현실에 알맞은 연극이 생산되어야한다는 것은 이 시기 극작가들에게는 중요한 문제였다. 1960년대 이근삼을 필두로 시작된 새로운 연극의 창작은 그 중심에 서사극 이론이 자리 잡고 있다. 서사극은 당시 변화된 시대상과 연극 양식을 수용하기에 알맞은 방법으로 많은 극작가들에게 지속적으로 영향을 주었다. 서사극은 불합리하고 위협적인 세계에 살고 있는 인간의 실존적 문제와 사회의 모순 부조리를 위트 있게 그려낸다. 관객들은 이러한 모순과 부조리에 웃음으로 반응함으로서 현재의 문제를 인식하고 공감한다. 서사극에 영향을 받은 현대 연극은 단지 보는 연극에서 그치지 않고 그 감흥을 자신의 의식으로 끌어들여와 숨겨진 도덕적 사회적 문제를 재인식하게끔 한다. 그러나 반공이 국시였던 1960 년대는 현실에 대한 비판을 직접적으로 드러낼 수 없었기 때문에 극작가들은 서사극의 이념적 성격을 그대로 수용하기 보다는 형식적 측면만 수용하였다. 그리고 서시극의 수용과 창작은 굴절과 변이의 과정을 거쳐 1970년대를 지나 1980년대에 이르러 ‘한국적인 서사극’으로 변용된다. 1980년대 활발한 활동을 한 이강백 이현화 황석영은 이러한 서사극적 이념에 동의하면서 한국적 상황과 현실에 소홀하지 않았다. 이강백은 70년대의 비유극에서 출발하여 80 년대 복잡한 시대상황과 사건에 대해 현실적 소재를 선택하여 서사극적 역량을 보여 주었다 이현화는 70년대 작품에서 보여준 개인의 실존문제와 은닉된 권력과 폭력성에서 벗어나 진실된 역사의 자리매김 사회개혁의 의지가 표현된 서사극으로 80 년대 사회상을 표현하였다. 그리고 황석영은 1970년대 중반 이 후 「장길산」의 연재를 제외하고 희곡만 집필한 것을 상기해 본다면 그의 관심은 역사적 혼란기 속에 숨겨진 진실된 우리의 모습이었다. 그는 시대적 모순을 알리고 분단시대의 상황과 비극을 알리기 위해 서사극적 기법을 수용하여 관객들에게 감동을 선사하였다. 서사극은 서구의 연극 이론이지만 한국의 현실에 알맞게 변용되어 재현되었다. 서사극은 현대연극에 중요한 사상적 기반이 되었다 그러므로 서시극의 이념성을 온전히 수용한 1980년대 희곡을 통해서 현대극이 갖는 의미를 밝힘으로써 일단의 연극적 경향을 이해할 수 있으리라 생각한다. 1960s, Korea society have experienced not only a Modernization but also a Variation in various field of Politics, Economy and Society etc. Likewise Drama is required new style to adapt to period change is showed a different features of Realism in past generations. Like this, modernism of Drama is a reformed the aspect from a reference point in 1960s. This is the reason why we have resolved. a new Drama creation in external element. This prepare for escape opportunity from the closing as stimulate to work field frank with the Epic Drama and absurdity Drama of the Western style. The creation of new style of play is Epic Drama theory which start with Lee keun-sam. Epic Drama theory is firm of innovation purpose of socialism for society organization due to take a criticism by practical behavior. Like this, Epic Drama of Brecht is accepted of theory of Frisch, Durrenmatt accede to theory of Brecht due to the political doctrine. Finally, Korea play is influenced by Brecht, is accepted of an analysis for play than the theoretical and technical point of view of Epic Drama. However, Epic Drama have an effect on the many dramatist of our changing phases of the times of the proper way to accept a style of play 1T0m 1960s Epic Drama, in a different way realism, clarify a social contradiction, irregularities and existential issues. A spectator feel sympathy for current situation exactly as against social contradiction, irregularities. They have a new understanding of the hidden social and moral issues, which not only watching the play but also self-consciousness. However, korean Epic Drama is displayed in the different aspect, Drama of the Western style, as accepted of the Epic Dramatic ideology. This is, a spectator feel sympathy for a player which present a drama as listen to the appealing inside voice. Because of their true picture of reality is similar to the picture of that player, they cannot neglect despair. Furthermore, korean Epic Drama is important purpose of social reform than our life in the present. These attitude of mind make a korean Epic Drama as accept theory of Epic Drama. Therefore, the paper presents Epic Drama reappear in different Drama of the Western style: nevertheless Epic Drama contribute development of the korea modern drama. The paper presents Lee Kang-Back, Lee Hyun-hwa, Hwang Suk-Young pursue simultaneity ofDrama feel sympathy for reality of the 1980s. Social issue and reality is writing material at that time use a techniques of Epic Drama. They want to arouse sympathy through an our image for time for living at day's. Like Epic Drama of Brecht, they focus on our image for live in comfortable circumstances. Similarity, it is be expressed a same point of view at construction of a sentence: a pain in a petit bourgeois use a narrator, the same sense of continuity between past and present which dramatize a events of history: with a song of anger and hopelessness Through a Drama, they confirmed our life as show the present conditions dramatically. The character of Korea Epic Drama is expressed in different Epic Drama of Brecht their point of view revealed with contemporary writers in 1980s.

액티브 네트워크 환경에서 실행 코드 교체를 위한 효율적인 캐싱 기법

조정희(Jung-Hee Cho),김동혁(Dong-Hyuk Kim),장창복(Chang-Bok Jang),조성훈(Sung-Hoon Cho),최의인(Eui-In Choi) 한국멀티미디어학회 2004 한국멀티미디어학회 학술발표논문집 Vol.2004 No.1