• Korean System Dynamics Review
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• v.14 no.2
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• pp.5-30
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• 2013

The concept of resilience in complex and adaptive socio-economic systems, has been a buzz word in international societies and academies related to policy makers for sustainable development since some years ago. This paper deals with an application of the resilient concept, which has been told since the last some decades in the field of ecology and applied system sciences, to social science especially in system dynamics. First the author introduces the concept of equilibrium stability and resilience in simple dynamic models, and moreover provides the behavioral characteristics and examples of system resilience in terms of system dynamics. The concept of resilience in structural perspectives are also discussed with the topics of panarchy and adaptive renewal cycles, etc.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.527-528
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• 2011

송전선로에서 발생하는 고장의 대부분은 낙뢰에 의한 상-대지간 섬락이나 외물접촉, 혹은 애자련의 오손에 의한 절연파괴 등이 대부분이다. 그리고 대분의 고장은 큰 고장전류를 흘리게 되어 보호계전기가 동작하여 고장구간을 신속하게 분리하게 된다. 그러나, 본 고장사례는 매우 희귀한 고장 사례로서, 고저항 아크 지락에 의하여 발생하는 과도회복전압(TRV: Transient Recovery Voltage)이 애자련에 섬락을 일으킨 경우이다. 본 연구에서는 EMTP (Electro-Magnetic Transient Program)를 이용하여 고저항 지락시 아크의 단속에 의하여 과도회복전압이 발생할 가능성이 있음을 보였으며, 고장기록장치(Fault Recorder)에 나타난 파형 기록과의 유사성을 확인하였다. 또한, 고저항 지락에 의하여 직류분이 초기에 방전됨으로써 고장전류 파형에 직류분 오프셋이 나타나지 않게 됨을 밝혔다.

• Journal of the Korean Society for Precision Engineering
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• v.21 no.6
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• pp.22-27
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• 2004

특성에 대한 많은 연구가 진행되었고, 새로운 나노 소자로서의 가능성을 보여왔다. CNT의 전기적 성질은 직경과 chirality 의 함수로서 금속 혹은 반도체 성질을 주기적으로 가지며, 이론적 연구에 의하면 단일구역의 CNT 는 1/3 이 금속성, 나머지는 밴드갭이 수 ㎷ 로 아주 작고, 나노튜브의 직경에 반비례하는 반도체 성질을 나타낸다.(중략)

• Clinics in Shoulder and Elbow
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• v.14 no.1
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• pp.105-110
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• 2011

Purpose: The purpose of this article is to identify and understand the complications of RTSA and to review the current methods of preventing and treating this malady. Materials and Methods: Previous constrained prostheses (ball-and-socket or reverse ball-and-socket designs) have failed because their center of rotation remained lateral to the scapula, which has limited of the motion of the prostheses and produced excessive torque on the glenoid component, and this leads to early loosening. The Grammont reverse prosthesis imposes a new biomechanical environment for the deltoid muscle to act, thus allowing it to compensate for the deficient rotator cuff muscles. Results: The clinical experience does live up to the lofty biomechanical concept and expectations: the reverse prosthesis restores active elevation above $90^{\circ}$ in patients with a cuff-deficient shoulder. However, external rotation often remains limited and particularly in patients with an absent or fat-infiltrated teres minor. Internal rotation is also rarely restored after a reverse prosthesis. Failure to restore sufficient tension in the deltoid may result in prosthetic instability. Conclusion: Finally, surgeons must be aware that the results are less predictable and the complication/revision rates are higher in revision surgery than that in the first surgery. A standardized monitoring tool that has clear definitions and assessment instructions is surely needed to document and then prevent complications after revision surgery.

• The Korean Journal of Nuclear Medicine
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• v.37 no.4
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• pp.245-253
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• 2003

Puorpose: The purpose of this study was to evaluate the usefulness of $^{99m}Tc$ DMSA scintigraphy on the dignosis of a renal scar in children with urinary tract infections. Materials and Methods: Eighty three patients were included in this study, who were diagnosed as the urinary tract infection on the basis of symptom, urinalysis and urine culture. $^{99m}Tc$ DMSA scintigraphy and voiding cystoureterography were peformed within 7days before the treatment in all patients. We classified the scintigraphic findings as follow s : 1 ; a large hypoactive upper or lower pole. 2 ; a small hypoactive area. 3 ; single defect resulting in localized deformity of the outlines. 4 ; deformed outlines in a small or normal sized kidney. 5 ; multiple defects. 6 ; diffuse hypoactive kidney without regional impairment. Follow-up scintigraphy was done at least 6 months after the initial study. When the abnormality on the initial scintigraphy was not completely resolved on the follow-up scan, the lesion was defined as containing a scar. Results: One hundred and fifteen renal units of 166 units(69.3%) showed abnormal findings on the DMSA scintigraphy. 65 units(56.5%) was diagnosed as containing renal scars on follow-up scintigraphies. Incidences of renal scar among renal units showing pattern 3, 4 and 5 on the initial scan was 75%, 78% and 78%, respectively. Whereas many of renal units showing 1, 2 and 6 pattern were recovered(65%, 76%, 50%). Sensitivity, specificity and accuracy of pattern-based DMSA scintigraphic findings on the diagnosis of renal scar was 76.9%, 85.1% and 81.9%, respectively. VUR was significantly associated with the renal scar when the initial DMSA shows unrecoverable findings(pattern 3, 4, 5). Odds ratio of the renal scar in a kidney showing unrecoverable initial scintigraphic findings was 19.1. Odds ratio in a kidney with mild or moderate-to-severe VUR was 3.5 and 14.4 respectively. Conclusion: In the urinary tract infection, renal scar was significantly developed in a kidney showing unrecoverable findings on the initial DMSA scan and VUR on voiding cystoureterography.

• Korean Journal of Heritage: History & Science
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• v.50 no.2
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• pp.62-79
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• 2017

The principle of repairing the architectural heritage in China was first presented by Liangsicheng of Society for Research in Chinese Architecture in the 1930s, and it was stated as "Restoration of Historic Condition or Preservation of Existing Condition" in 1961 in the "Provisional Regulations on the Protection and Management of Cultural Relics" after various repair experiences under the social and political background of the 1950s. Restoration of historic condition generally means restoration to original shape, and because architectural heritage was often repaired based on similar principle in Korea and Japan in the early and mid 20th century, it can be said that the restoration of historic condition was a universal and leading principle in this period in Northeast Asia. In China, however, the preservation of existing condition is equally specified along with the restoration of historic condition. When considering the leading trend of the time, it seems to be rather unexpected, which leads to questions about the formation process and meaning. The research on Liangsicheng, which first suggested the principle of repair, is very important, but there is a lack of three-dimensional analysis of his principles compared with active research on international principles in China. In order to understand the process of formation and its meaning of the principle of repair in China, we first need to analyze the principle proposed by Liangsicheng, and it is necessary to comprehensively examine how the principle have changed under the social background surrounding architectural heritage conservation after the founding of the People's Republic of China(PRC). In this paper, we first show that Liangsicheng has proposed a principle of restoration of historic condition with important values in the originality, and at the same time he opened the possibility of preservation of existing condition for the result of value judgment or realistic reason. In addition, we examine the process of equalizing preservation of existing condition with a restoration of historic condition as a realistic principle due to the influence of Soviet architectural heritage conservation system and Chinese economic development oriented policy after the founding of PRC.

• Journal of Dental Rehabilitation and Applied Science
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• v.32 no.2
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• pp.123-129
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• 2016

Whereas a somatic pain notifies tissue damage, a neuropathic pain presents disorder of the nerve itself. The causes of neuropathic pains are trauma, infection, chronic irritation by adjacent tissue and so on. The iatrogenic trauma or infection also causes traumatic neuropathy, which may exert a bad influence on doctor-patient relationship. Some of related dental treatments are implantation (directly or indirectly through heating), root canal treatment, teeth extraction, block anesthesia, mandibular surgery. If inappropriate management is performed after nerve trauma, there will be many chances to develop chronic neuropathy for the patient. It is important that the sign of nerve trauma have to be caught by the practitioner as soon as possible and treated properly.

• Journal of Chest Surgery
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• v.32 no.5
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• pp.422-427
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• 1999

Background: Tachycardia induced heart failure model would be the model of choice for the dilated cardiomyopathy. This more closely resembles the clinical syndrome and does not require major surgical trauma, myocardial ischemia and pharmacological or toxic depression of cardiac function. When heart failure is progressive, application of new surgical procedures to the faling heart is highly risky. It has been shown that recovery trajectory from heart failure is a new method in decreasing animal mortality. The purpose is to establish the control datas for recovery trajectory in the canine heart failure model. Material and Method: 21 mongrel dogs were studied at 4 stages(baseline, at the heart failure, 4 and 8 weeks after recovery). Heart failure was induced during 4 weeks of continuous rapid pacing using a pacemaker. Eight weeks of trajectory of recovery period was allowed. Indices of left ventricular function and dimension were measured every 2 weeks and the hemodynamics were measured by use of Swan-Ganz catheterization and thermodilution method every 4 weeks. Values were expressed as mean${\pm}$standard deviation. Result: 4(20%) dogs died due to heart failure. Left ventricular end-diastolic volume at the 4 stages were 40.8${\pm}$7.4, 82.1${\pm}$21.1, 59.9${\pm}$7.7 and 46.5${\pm}$6.5ml. Left ventricular end-systolic volume showed the same trend. Ejection fractions were 50.6${\pm}$4.1, 17.5${\pm}$5.8, 36.3${\pm}$7.3, and 41.5${\pm}$2.4%. Blood pressure and heart rate showed no significant changes. Pressures of central vein, right ventricle, pulmonary artery, and pulmonary capillary wedge showed significant increase during the heart failure period, normalizing at the end of recovery period. Stroke volumes were 21.5${\pm}$8.2, 12.3${\pm}$3.5, 17.9${\pm}$4.6, and 15.5${\pm}$3.4ml. Blood norepinephrine level was 133.3${\pm}$60.0pg/dL at the baseline and 479.4${\pm}$327.3pg/dL at the heart failure stage(p=0.008). Conclusion: Development of tachycardia induced heart failure model is of high priority due to ready availability and reasonable amenability to measurements. Recovery trajectory after cessation of tachycardia showed reduction of cardiac dilatation and heart function. Application of new surgical procedures during the recovery period could decrease animal mortality.

• Korean Chemical Engineering Research
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• v.48 no.6
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• pp.700-703
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• 2010

In this study, plant extracts including Eucommia ulmoides Oliv. and Phellodendron amurense were studied to test possible application for cosmetics and skin related medicine. Anti-oxidation effect of plant extracts was measured by DPPH free radical scavenging activity and it was insignificant at low concentration, however, it was as good as vitamin C, excellent anti-oxidation agent, at $1000{\mu}g/ml$. Anti-bacterial effect was tested by disc diffusion method, and plant extracts showed mild anti-bacterial effect for normal skin flora, Staphylococcus epidermidis while it indicated strong anti-bacterial effect for acne inducing Propionibacterium acne. Therefore it had powerful potential for anti-acne material because of selectivity. Anti-atopic dermatitis effect was tested by hairless mouse and plant extracts recovered damaged skin to near normal condition after 14 days of treatment. IgE concentration in treated mouse was decreased 16% compared with control. From the research, plant extracts indicated strong anti-acne and anti-atopic dermatitis effect, and showed strong potential for cosmetics and skin related medicine.

• Journal of the Korean Society for Marine Environment & Energy
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• v.6 no.2
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• pp.16-27
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• 2003

For the last decade, some 400 small and large oil spill accidents have occurred every year. Such accident blow a serious damage to the marine resource and ecosystem, which can't be estimated in terms of economic and environmental losses. The physical/chemical methods used currently may be effective at the initial stage of accidents, but they can't serve to remove the spilled oil completely. Moreover, the dispersant may lead to a secondary contamination detrimental to the lives inhabiting wet lands, beaches and tidal zone. Thus, a new decomposing technology Is required for the environmentally sensitive areas. Bioremediation is the active use of biological techniques to mitigate the consequences of a spill using biological processes and refers both of stimulation of pollutant biodegradation and/or to enhance ecosystem recovery Bioremediation is an economically attractive method for the clean-up of oil-contaminated area. Bioremediation has been demonstrated to be an effective oil spill countermeasure for use in cobble, sand beach, salt marsh, and mud flat environment.