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Root Morphology of Norway Spruce (Picea abies [L.] Karst.) in the Differently Acidified Forest Soils (토양(土壤) 산성화(酸性化) 정도(程度)에 따른 독일가문비나무(Picea abies [L.] Karst.))

  • Lee, Do-Hyung
    • Journal of Korean Society of Forest Science
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    • v.89 no.5
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    • pp.677-684
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    • 2000
  • This study was conducted to investigate the relationship of development of root and soil condition and also to elucidate the difference between stands for mechanical and physical stability according to distribution of roots in the Norway Spruce (Picea abies [L.] Karst.) stands of 30 to 40 year of ages with different soil condition. In the root structure, remarkably different root pattern was shown among the three stands; Eberg$\ddot{o}$tzen stand showed large number f roots with much fine roots which deeply in vertical direction while Barbis stands had thicker root and small number of root than Eberg$\ddot{o}$tzen stand. The Weidenbrunnen stand showed differently half-vertical and plate root structure and the root developed not to be deeply compared to the other two stands. In the total number of root, Eberg$\ddot{o}$tzen stand had the most number of 74 and Barbis stand 33, Weidenbrunnen stand 57 respectively. Eberg$\ddot{o}$tzen stand had much more number of vertical root with 57 than the other two stand; Barbis 21 and Weidenbrunnen 36. In the total length of root, Weidenbrunnen stand showed to be longer than the other two stands and the length of horizontal root also showed longer. Regarding to the rates of horizontal root against vertical root, Eberg$\ddot{o}$tzen stand showed comparatively higher value as 1,2 than other two stands(0.5). In the total weight of root, Weidenbrunnen stand showed very high value compared with the other stands and ratio of vertical root against horizontal root was 0,16 which is very lower than the other two stands(0,4). The remarkable differences of root pattern of Norway spruce stands appeared in this study are through to be caused more by chemical property of soil such as acidity den the mechanical or physical factor of soil conditions.

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Review on the Justifiable Grounds for Withdrawal of Meaningless Life-sustaining Treatment -Based on a case of Supreme Court's Sentence No. 2009DA17417 (May 21, 2009)- (무의미한 연명치료 중단 등의 기준에 관한 재고 - 대법원 2009.5.21 선고 2009다17417사건 판결을 중심으로 -)

  • Moon, Seong-Jea
    • The Korean Society of Law and Medicine
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    • v.10 no.2
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    • pp.309-341
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    • 2009
  • According to a case of Supreme Court's Sentence No. 2009DA17417 (May 21, 2009), the Supreme Court judges that 'the right to life is the ultimate one of basic human rights stipulated in the Constitution, so it is required to very limitedly and conservatively determine whether to discontinue any medical practice on which patient's life depends directly.' In addition, the Supreme Court admits that 'only if a patient who comes to a fatal phase before death due to attack of any irreversible disease may execute his or her right of self-determination based on human respect and values and human right to pursue happiness, it is permissible to discontinue life-sustaining treatment for him or her, unless there is any special circumstance.' Furthermore, the Supreme Court finds that 'if a patient who is attacked by any irreversible disease informs medical personnel of his or her intention to agree on the refusal or discontinuance of life-sustaining treatment in advance of his or her potential irreversible loss of consciousness, it is justifiable that he or she already executes the right of self-determination according to prior medical instructions, unless there is any special circumstance where it is reasonably concluded that his or her physician is changed after prior medical instructions for him or her.' The Supreme Court also finds that 'if a patient remains at irreversible loss of consciousness without any prior medical instruction, he or she cannot express his or her intentions at all, so it is rational and complying with social norms to admit possibility of estimating his or her own intentions on withdrawal of life-sustaining treatment, provided that such a withdrawal of life-sustaining treatment meets his or her interests in view of his or her usual sense of values or beliefs and it is reasonably concluded that he or she could likely choose to discontinue life-sustaining treatment, even if he or she were given any chance to execute his or her right of self-determination.' This judgment is very significant in a sense that it suggests the reasonable orientation of solutions for issues posed concerning withdrawal of meaningless life-sustaining medical efforts. The issues concerning removal of medical instruments for meaningless life-sustaining treatment and discontinuance of such treatment in regard to medical treatment for terminal cases don't seem to be so much big deal when a patient has clear consciousness enough to express his or her intentions, but it counts that there is any issue regarding a patient who comes to irreversible loss of consciousness and cannot express his or her intentions. Therefore, it is required to develop an institutional instrument that allows relevant authority to estimate the scope of physician's medical duties for terminal patients as well as a patient's intentions to withdraw any meaningless treatment during his or her terminal phase involving loss of consciousness. However, Korean judicial authority has yet to clarify detailed cases where it is permissible to discontinue any life-sustaining treatment for a patient in accordance with his or her right of self-determination. In this context, it is inevitable and challenging to make better legislation to improve relevant systems concerning withdrawal of life-sustaining treatment. The State must assure the human basic rights for its citizens and needs to prepare a system to assure such basic rights through legislative efforts. In this sense, simply entrusting physician, patient or his or her family with any critical issue like the withdrawal of meaningless life-sustaining treatment, even without any reasonable standard established for such entrustment, means the neglect of official duties by the State. Nevertheless, this issue is not a matter that can be resolved simply by legislative efforts. In order for our society to accept judicial system for withdrawal of life-sustaining treatment, it is important to form a social consensus about this issue and also make proactive discussions on it from a variety of standpoints.

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Immunogenicity and Reactogenicity of Inactivated HM175 Strain Hepatitis A Vaccine in Healthy Korean Children (건강한 한국 소아에서 HM175주 A형 간염 불활화 백신의 면역원성 및 이상반응에 관한 연구)

  • Kim, Chang Hwi;Pyun, Bok Yang;Hong, Young Jin;Kang, Jin Han
    • Pediatric Infection and Vaccine
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    • v.7 no.1
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    • pp.120-128
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    • 2000
  • Purpose : Active immunization against hepatitis A with an inactivated vaccine reveals excellent immunogenicity, tolerability and protective efficacy. Inactivated hepatitis A vaccines have been selectively used since 1996 in Korea to prevent hepatitis A. This study was performed to assess the immunogenicity and reactogenicity after two doses of HM175 strain hepatitis A vaccine in healthy Korean children. Methods : 128 healthy children(M/F; 65/63) aged 1 to 15 years, who were seronegative for hepaitatis A, participated in this study. A alum-adsorbed vaccine containing 720 EL.U of antigen form HM175 hepatitis A strain per 0.5 mL dose was injected intramuscularly on the deltoid area. The second dose was given 6 months later, Anti-HAV antibodies were measured by ELISA before and 1 month after each vaccination to assess the immunogenicity. Any local and general adverse events were reported by patients parents with the prepared questionnaire after each vaccination. Results : 120 volunteers(M/F; 60/60) completed the whole series of the study. Seroconversion occurred in all cases after primary and booster vaccination. The mean anti-HAV antibody titer after primary vaccination was 389.2mIU/mL, and 3,609mIU/mL after booster vaccination. And levels of anti-HAV antibodies after booster immunization were significantly higher in female children. The most common local adverse event was soreness on the injection site, but it was mild and resolves within 3 days. Fever was not reported after booster vaccination. Conclusion : Based on these data, we conclude that the inactivated HM175 strain hepatitis A vaccine is highly immunogenic and tolerable in healthy Korean children.

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Distribution and Growth of Bacteria in the Hypertrophic Lake Shiwha (과영양성 시화호에서 박테리아의 분포 및 성장)

  • Choi, Dong-Han;Kang, Sulk-Won;Song, Ki-Don;Huh, Sung-Hoi;Cho, Byung-Cheol
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.2 no.2
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    • pp.92-100
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    • 1997
  • Distribution of bacterial abundance and production was investigated during October, 1995-August, 1996 in Lake Shiwha constructed artificially in 1994. Its water column was distinguished by two layers: the brackish surface layer with salinity ranged from 6 to 20‰ and the saline hypoxic/anoxic bottom layer with salinity of 17 to 27‰ Except for samples collected in March, 1996 (on average 13 ${\mu}g\;l^{-1}$), chlorophyll a concentration ranged from 27.6 to 249.5 ${\mu}g\;l^{-1}$ in the euphotic zone, indicating the hypertrophic condition of Lake Shiwha during most of the studied period. In this study, bacterial productions measured by $^3H$-thymidine incorporation method were similar to those by $^{14}C$-leucine incorporation method. In hypertrophic, surface waters of Lake Shiwha, bacterial abundance and production ranged from 1.4 to $19.5{\times}10^9\;cells\;l^{-1}$ and from 1.6 to $126.5{\times}10^7\;cells\;l^{-1}\;h^{-1}$ respectively; 2 to 4 fold and 2 to 30 fold higher than those in eutrophic coastal waters outside of Lake Shiwha, respectively. Turnover times of bacterial community in the surface layer of Lake Shiwha ranged from 0.2 to 8.9 day, indicating that bacteria in the lake seemed to adapt to the hypertrophic condition. In the hypoxic bottom layer, bacterial abundance and production was up to 3 fold and 20 fold lower than those in the surface layer, and showed slow bacterial growth. Significant correlations between the bacterial abundance, production, and community turnover time with water temperature indicate water temperature was the important factor controlling distribution and growth of bacteria. However, during summer season, bacterial production seemed to be regulated by supply of substrates.

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A Study on the Presence of Post-Miesianism and Its Future (Post-Miesianism의 실체와 미래에 대한 연구)

  • Lee, Sang-Jin
    • Journal of architectural history
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    • v.10 no.4 s.28
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    • pp.77-92
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    • 2001
  • 현대의 건축시기는 다원성의 시기 또는 복합성의 시기라고 불리운다. 모더니즘과 포스트모더니즘의 시기를 거치며 다양한 형태적 실험의 과정을 겪었고 수많은 이데올로기와 이론들로 무장된 논쟁의 역사도 갖게 되었다. 이러한 현대건축의 다양성은 건축디자인이라는 전문직의 사회에 기여하는 역할을 반추(反芻)함과 동시에 다변하는 인간사고의 역동성을 반영하고 있다. 건축관련 책자나 저널 등에서 흔히 발견할 수 있는 Neo-Classicism, Deconstructivism, Minimalism, High-Tech, New Moderns 등등의 건축양식들은 스타일을 지칭하는 언어라기보다는 건축적 사고를 지칭하는 언어라고 할 수 있다. 결국 건축디자인이라는 작업은 인간을 둘러 싼 건조환경의 생성에서 출발하는 것이므로 건축적 사고방식은 그 시기의 사회현상과 밀접한 관계를 맺게 된다. 20세기 말부터 불어닥친 디지털 문화의 사회변혁은 전 세계를 하나의 채널로 엮게 되었고, 이러한 영향들은 지역과 민족, 그리고 종교적인 요소들까지도 혼합하여 국경을 초월한 미래의 새로운 이상들을 꿈꾸게 되었다. 19세기 산업혁명과 함께 급속히 벨라진 인류문명의 진보는 필수적으로 세계화를 동반하는 것이고, 세계화와 지역성사이의 괴리를 통해 나타나는 문화적 비판과 충돌은 아직도 진행상태인 것이다. 세계화라는 통염은 문명의 보편성을 기반으로 하며 전통문화의 파괴가 뒤따를 수밖에 없는데, 현재와 같이 IT혁명을 통해 급속도로 빨라진 세계문화의 교류는 한 국가가 뿌리를 내리고 있는 문화적 유산이라는 토양을 포기하여야 할 단계에 와 있다고 논평할 정도이다. 여기서 건축은 문화적 상징으로 작용하게 되는데, 그것이 심미적이든 관습적이든 또는, 경제적이든 건축가는 해답의 제시라는 임무에 직면하게 된다. 20세기에 진행된 모더니즘의 건축은 구조와 공간에 대한 고전건축의 숙원을 고덕건축이 이룬 것처럼 15세기 르네상스 시대로부터 진행된 형태와 공간, 기능, 그리고 아름다움과 기술(technology) 또는 경제성 등에 대한 건축적 의문과 탐구를 일단락지었다고 할 수 있다. 이러한 모더니즘의 한복판에 Mies van der Rohe라는 거장이 깊은 발자국을 남기며 한 시대를 이루었고 그가 남긴 시대정신의 이념과 가치를 Miesianism이라고 부른다. 실용성과 도덕성을 근본으로 하는 Miesianism은 대중에 호소하는 미적 표현주의를 부정하고 지역정서를 중시하는 문맥적 접근방식을 경시함으로써 보편화라는 현상을 불러일으킨 국제주의 양식의 한 부류로 비판을 받아왔다. 즉, Miesianism의 단순하고 강렬한 외형적 요소는 그것이 내포하는 기술적 합리성이나 공간적 완결성을 무시한 채 전 세계에 영향을 미쳤고 동시에 지역적 저항을 받게 되었다. 시카고 및 전 세계의 Miesian들, 즉 Mies van der Rohe의 제자들이나 그로부터 영향을 받은 수많은 건축가들은 이러한 저항과 비판에 직면하게 되며 새로운 사고의 시대적 요구 앞에 고뇌하게 된다. 한국에서는 1978년 Mies van der Rohe의 제자인 김종성이 미국에서 서울로 돌아와 '서울건축컨설탄트'를 설립하며 본격적으로 Miesianism의 규범적 건축론을 설파하기 시작하였다. 이른바 시카고 국제주의학파의 건축전수라고 할 수 있는데 '서울건축컨설탄트'를 통하여 배출된 김종성의 제자들은 명쾌하고도 간결한 건축해법의 경험을 토대름대로의 정체성을 갖고자 노력하였으나 결국 다원적 가치를 요구하는 시대적 흐름 속에 혼란을 겪고 있는 것 또한 사실이다. 본 연구는 Miesianism의 기원을 밝히고 그것의 실수와 오류를 밝힘과 동시에 현대의 여러 가지 건축유형들과 비교하여 봄으로써 Post-Miesianism의 실체와 그 미래에 대하여 고찰하여 보고자 한다. 미스의 유산이라고 할 수 있는 Miesianism의 요체는 첫째, Schinkel로부터 이어받은 시대정신의 사명감, 둘째, Berlage가 전해준 전문가로서의 도덕성을 바탕으로 하여 이루어진 기술적 합리성의 실현, 그리고 마지막으로 그 당시의 추상예술에 대한 이해로써 받아들인 nee-Suprematism의 아방 가르데적인 자세라고 할 수 있다. 그러나 이것들을 전파하고 수용하는 과정에서 미스적인 단순하고 명쾌한 외관이 더욱 강한 인상을 남기게 되었고 또한 미스가 현대성의 본질이라고 믿는 기술의 전수는 모든 외관을 동일하게 만드는 International Style로서의 보편적 획일성을 초래하였다. Mies van der Rohe의 강력하고 규범적인 dogma는 그의 제자들에게는 강렬한 카리스마로 각인되었고, Mies가 원한 것이 아닐지라도 그들을 하나의 틀 속에 가두는 영향력을 행사하였다. 2세대이든 3세대이든 기술적 합리성과 추상적 단순미라는 믿음을 맹목적으로 추종할 때 그들은 Miesian으로 남아있게 되며, 거기서 벗어났을 때 non-Miesian, 또는 배신자로 취급하기까지 하였다. 이것은 미스의 제자들에게 강한 족쇄가 되어 형태적 또는 개념적 변화의 시도를 어렵게 하였고 시대적 요구에 부응하지 못한다는 평가에 이르게 되었다. 문화의 다양성과 역동성을 인정함과 동시에 Miesianism에 대한 새롭고 시대에 적합한 해석을 기대하게 되는데, 이러한 기대 속에서 우리는 Post-Miesianism이라는 새로운 유형을 엿볼 수 있게 된다. Post-Miesianism의 징후를 현대의 다양한 건축유형에서 발견할 수 있는데, High-Tech의 구축적이고 정밀한 건축 기술적 해법과 Minimalism의 반복성을 통한 추상미의 표현 등에서 뿐만이 아니라 Post-Modernism의 인간성의 추구나 문맥적 고려, 또는 해체주의의 형이상학적이고 아방가르데적인 실험주의 정신까지조차 Post-Miesianism이 공유할 수 있는 부분이 있다고 보여진다. 또한, 미스의 영향이 2세대, 3세대의 건축가들에게 미치면서 여러 방향으로 변질되어 가는 것을 우리는 발견할 수 있으며 그러한 시대성에 적응하는 시도들이야말로 새로운 미래를 향한 Post-Miesianism의 실체인 것이다. Mies가 말하였듯이 한 시대의 끝은 그 시대가 완전히 이해되었을 때이며, 모더니즘의 숙제는 아직 해결되지 않았으므로 Miesianism의 탐구는 Post-Miesianism이라는 새로운 주제로 계속될 것이다. 이를 통하여 21세기 디지털 문명의 시대 속에서 현대건축이 안을 수밖에 없는 보편성과 지역성의 충돌이라는 문제의 해결에 한 발걸음 다가갈 수 있기를 기대하여 본다.

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Development of Evaluation Method for Jointed Concrete Pavement with FWD and Finite Element Analysis (FWD와 유한요소해석을 이용한 줄눈콘크리트포장 평가법 개발)

  • Yun, Kyong-Ku;Lee, Joo-Hyung;Choi, Seong-Yong
    • International Journal of Highway Engineering
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    • v.1 no.1
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    • pp.107-119
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    • 1999
  • The joints in the jointed concrete pavement provide a control against transverse or longitudinal cracking at slab, which may be caused by temperature or moisture variation during or after hydration. Without control of cracking, random cracks cause more serious distresses and result in structural or functional failure of pavement system. However, joints nay cause distresses due to its inherent weakness in structural integrity. Thus, the evaluation at joint is very important. and the joint-related distresses should be evaluated reasonably for economic rehabilitation. The purpose of this paper was to develop an evaluation system at joints of jointed concrete pavement using finite element analysis program, ILLI-SLAB, and nondestructive testing device. FWD. To develop an evaluation system for JCP, a sensitivity analysis was performed using ILLI-SLAB program with a selected variables which might affect fairly to on the performance of transverse joints. The most significant variables were selected from precise analysis. An evaluation charts were made for jointed concrete pavement by adopting the field FWD data. It was concluded that the variables which most significantly affect to pavement deflections are the modulus of subgrade reaction(K) and the modulus of dowel/concrete interaction(G), and limiting criteria on the performance of joints at JCP are 300pci. 500,000 lb/in. respectively. Using these variables and FWD test, a charts of load transfer ratio versus surface deflection at joints were made in order to evaluate the performance of JCP. Practically, Chungbu highway was evaluated by these evaluation charts and FWD field data for jointed concrete pavement. For Chungbu highway, only one joint showed smaller value than limiting criterion of the modulus of dowel/concrete interaction(G). The rest joints showed larger values than limiting criteria of the modulus of subgrade reaction(K) and the modulus of dowel/concrete interaction(G).

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Clinical Experiences of redo-CABG (관상동맥우회 재수술의 임상적 고찰)

  • Lim, Sang-Hyun;Kwak, Young-Tae;Lee, Sak;Chang, Byung-Chul;Kang, Meyun-Shick;Cho, Bum-Koo;Yoo, Kyung-Jong
    • Journal of Chest Surgery
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    • v.35 no.11
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    • pp.779-784
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    • 2002
  • Recently, the number of coronary artery bypass surgery(CABG) is increasing according to the increasing incidence of coronary artery disease. However, CABG is not a definite corrective surgery; therefore, in some patients, redo-CABG may be required. We retrospectively reviewed our redo-CABG experiences to help future redo-CABG. Material and Method: From January 1991 to April 2001, 14 cases of redo-CABG were performed in Yonsei Cardiovascular Center(M:F=12:2) and mean age was 61,7 $\pm$ 7.1(47-72) years. Mean time from 1st. CABG to redo-CABG was 121.9 $\pm$ 50.5(6.1-179.6) months. Thirteen cases were conventional on-pump CABG and one case was off-pump CABG. In two patients, mitral valve re-replacement and mitral valve repair were performed each. All redo-CABG were performed through mid-sternotomy. During redo-CABG, left internal mammary artery and saphenous vein grafts were used in 6 patients, left internal mammary artery and left radial artery grafts were used in 2 patients, left internal mammary artery and gastroepiploic artery were used in one patient and only greater saphenous veins were used in 5 cases(In one case, cephalic vein was also used). The number of mean distal anastomosis was 2.1 $\pm$ 0.9(1-4). Result: There were no operative death and no perioperative myocardial infarctions and cerebrovascular accidents or other heart related complications. Mean follow up duration was 40.1 $\pm$ 38.6(1.1-118.5) months. During follow up period, angina was re-developed in one patient 13 months after operation. Two patients died of end-stage renal failure 14.8 months and 116.3 months after redo-CABG, respectively. During follow up period, coronary angiography was performed in 3 patients, and all grafts were patent. At last follow up, mean Canadian class was 1.3. Kaplan-Meier survival at 9 years was 90.0 $\pm$ 9.5% and event free survival at 9 years was 71.4 $\pm$ 6.9%. Conclusion: After redo-CABG, all patients improved their angina symptom and daily activity. And long-term survival after redo-CABG was excellent. Therefore, if patients have indications for redo-CABG, thenredo-CABG must be strongly recommended and performed.

Early and Mid-Term Results of MIDCAB (최소 침습적 관상 동맥 우회술의 중단기 성적)

  • 손호성;방영호;황진욱;민병주;조양현;박성민;이성호;김광택;선경
    • Journal of Chest Surgery
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    • v.37 no.10
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    • pp.827-832
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    • 2004
  • Background: The significance of MIDCAB is emerging topics recently as OPCAB is going to be universalized, and long-term outcome of bypass graft surgery was proved to be more excellent than balloon dilation or stent insertion. We report our MIDCAB results in 73 patients in the last three years. Material and Method: Retrospective analysis of medical records was done from November 1, 2000 through November 31, 2003. There were 47 males and 26 females ranging in age from 31 years to 79 years (average $61.3\pm9.8$ years). Observation periods after operative procedures were 10 to 1238 days (average $763\pm319.8$ days). Left longitudinal parasternal incision as a standard procedure was done to approach the heart after dissection of the left internal thoracic artery by partial or total resection of 3rd to 5th ribs. Result: Of those patients, 46 patients were transferred to ICU after extubation at operation room and 58 patients were extubated within 3 hours after operation. Average ICU staying periods was $26.8\pm11.5$ hours. Follow-up angiography during admission was done in 36 patients and showed 100% patency. Only one patient died on the 10$^{th}$ post operative day because of sudden CVA. Complications included wound problems in 4 patients, and constructing pericardial window using thoracoscopy due to continuous pericardial effusion in 1. Permanent pacemaker was inserted in one patient owing to sick sinus syndrome. In one patient with recurrence of angina 8 months after operation, stenosis at anastomic site was found and improved with balloon dilatation. Conclusion: We were satisfied with our results of MIDCAB in single and multi-vessel coronary artery disease. These results have made the cardiologists tried to operate positively and we expect widening operative indications including hybrid revascularization.

Changes in Subjective Symptom, Tear Film Stabilization and Blinking Rates when Wearing RGP Lenses with Different Polishing Conditions for Certain Period of Time (연마상태가 다른 RGP렌즈의 일정기간 착용 시 렌즈착용자의 자각적 증상, 눈물막 안정 및 순목횟수 변화)

  • Park, Mijung;Kim, Hyo Gyum;Bae, Jun Seob;Park, Jung Ju;Kim, So Ra
    • Journal of Korean Ophthalmic Optics Society
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    • v.19 no.1
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    • pp.31-42
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    • 2014
  • Purpose: The present study was conducted to investigate the effect of the physical properties of RGP lens induced by lens polishing on the actual wearer's subjective comfort, the tear film break-up time and the blinking rate as a follow-up study that revealed the relationship between the lens physical properties during lens manufacturing and lens wearer's factors. Methods: RGP lenses made from the three different polishing conditions (25, 50 and 100 seconds) were applied on 28 eyes of 17 subjects, aged 20 to 29 years, without any known disease and surgical history in the eyes. While the subjects were asked to wear the RGP lenses longer than a week, the questionnaire for the comfortability was administered everyday. Subjective and objective tear break-up time and blinking rate of the wearers were further measured. Results: The wearer's subjective comfortability showed some difference in the type of discomfort and satisfaction score according to the polishing status when wearing RGP lenses made from different polishing conditions longer than a week, and a bigger difference in satisfaction score induced by polishing condition was especially shown in experienced RGP lens wearer rather than un-experienced wearer. In the case of RGP lens wearer compared with the ones without the wearing experience, as the wearing time increased subjective and objective tear break-up time were increased and the blinking rate was decreased. However, subjective and objective tear break-up time were tended to decrease with even longer wearing time when wearing the RGP lens made from the polishment for 100 seconds. Conclusions: These results confirmed that the optimization of physical properties of the lens may not give the same effect on the wearer's subjective and objective symptoms and other factors when actual wearing. From the results, it can suggest that the success rate of RGP lens wear may be changed by physiological factors such as the stabilization of wearer's tear film, comfortability and lens wearing experience when wearing RGP lens based on 'The manufacturing standard for soft contact lens/hard contact lens' provided by Korea Food and Drug Administration.

Economic Welfare Study on Seasonal and Time Period Electricity Pricing (계시별 전력가격에 대한 경제적 후생 연구)

  • Yoo, Young-Hoon;Kim, SungSoo
    • Environmental and Resource Economics Review
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    • v.14 no.2
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    • pp.519-547
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    • 2005
  • The aim of this study is to analysis how economic welfare lost happens within the present korea seasonal and time period electricity pricing system and find out reasonable electricity price system acceptable during the transitional period of korea electricity industry restructuring To analyze economic welfare lost in the electricity industry, in advance seasonal and time periodic 9 demand curves(summer, spring &fall, winter/peak-load time, middle-load time, low-load time) and one market supply curve are made and then using these demand and supply curve, seasonal and time periodic market equilibrium prices is calculated. Finally, comparing these market equilibrium prices with present regulated classified seasonal and time periodic prices, the whole economic welfare lost in the electricity industry is calculated. The result of this study shows that in 2002, the total economic welfare lost in electricity industry is 137,770 million Won and under present price system, the worst welfare lost is happening seasonally in spring & fall, time periodically in the middle-load time. Specifically analyzing the characteristics of welfare lost, especially on the industry customers and service customers which are applied in seasonal and time periodic pricing, for the industry customers, the welfare lost calculated in this class occupies 51% of the total welfare lost in the whole electricity industry and the worst welfare lost is happening seasonally in spring & fall, time periodically in the middle-load time. For service customers, the welfare lost calculated in this class occupies 13% of the total welfare lost in the whole electricity industry and the worst welfare lost is happening seasonally in summer, time periodically in the peak time Finally, this study was made based on the year of 2002 and KEPCO has practiced two times of rate change until now. The result of rate change was positively analyzed in the direction of economic welfare improvement(welfare improvement achieved by 16.3% compared to 2002 result).

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