• Korean Journal of Animal Reproduction
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• v.26 no.2
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• pp.173-182
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• 2002

The mechanisms underlying of the visual assessment and resulting in optimum embryonic development following in vitro maturation, fertilization, and culture are unclear, It was known that in vitro produced embryos show more frequent occurrence of fragmentation, which resulted in poor developmental potential and decreased implantation rate. The objective of this study was to investigate the apoptotic rates in bovine blastocyst derived from in vitro fertilization (IVF) and nuclear transfer (NT). In addition, the expression levels of Bcl-2 and Bax gene were investigated in the blastocyst to confirm their potential roles in the regulation of apoptosis during preimplantation embryonic development. Analysis of apoptosis was carried out by using terminal deoxynucleotidyl transferase mediate dUTP nick end labeling (TUNEL) method. The levels of Bcl-2 and Bax gene in the blastocyst derived from IVF and NT were determined by RT-PCR. The proportion of TUNEL positive signal in blastocyst derived from NT was significantly higher than that in blastocyst derived from IVF (p<0.001). Bcl-2 expression level of blastocyst derived from IVF was higher than that of blstocyst derived from NT. However, high expression level of Bax was observed in the blastocyst derived from NT. These results indicates that apoptosis is more responsible for fiagmentation in bovine blastocyst derived from NT than IVF. These results suggested that the increase of developmental failure followed by NT could be caused by nuclear fragmentation as apoptosis.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.1
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• pp.35-44
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• 2020

The purpose of this study is to elaborate the request for proposal (RFP) for the localization parts development support project of core parts carried out by the Defense Agency for Technology and Quality. The RFP is the most important document throughout the localization parts project, including project announcement and developer selection, design and test of the development product, final evaluation, and standardization of the project. However, if the RFP is not established at the beginning of the project, there is an increased risk of business failure due to frequent changes by various reasons. In this study, we recognized the necessity of elaboration of RFP and applied the AHP method for quantitative elaboration. Eight requirements of the RFP related to the mechanical/electrical performance of localized development products and three elaboration methods for each requirement were designed in a hierarchical structure, and each weight was calculated by applying the 5-point scale AHP method. The AHP survey was conducted with 20 developers participating in the localization parts project, and the consistency ratio of the AHP survey result was less than 0.1. The elaboration method with the highest value among the calculated weights is classified, and the analysis results and future research directions of the elaboration method are presented.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.8 no.2
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• pp.178-186
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• 2015

Endurance time is very important indicator to estimate muscle fatigue. In the case of measuring endurance time directly, it is dangerous for subject to perform a test until the point of failure to main time force. Therefore, this paper presents the model to estimate endirance time using indirect measurements such as personal factors and anthropometrical data. Previous studies had shown that personal factors such as gender and age were not related to endurance time, but recently studies have shown that it is estimated by using independent variable or predictor such as GTA (Gravitational Torque of the horizontal, stretched arm) and MVC (Maximum Voluntary Contraction). The present study investigated variables to estimate endurance time using personal factors and anthrometrical data during isotonic contractions. Twenty five healthy subject volunteered for this study, and performed three test sessions of isotonic contraction exercises at 10~50% respectively. Afterward the correlation coefficient and p-values were compared among regression models using personal factors and anthropometrical data. The results demonstrated that multi-regression model had significant coefficient of correlation, and was useful estimate endurance time.

• The KIPS Transactions:PartC
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• v.13C no.4 s.107
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• pp.501-510
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• 2006

Software streaming allows the execution of stream-enabled software on desktop or portable computing devices like PC, PDA, laptop, cellular phone, etc., even while the transmission/streaming from the server may still be in progress. In this paper, we present an efficient streaming system called Software On-Demand(SOD) streaming system to transmit stream-enabled applications in addition to automatic installation of program registry, environment variables, configuration files, and related components. In particular, we design and implement a SOD system in Linux to provide the user with the instant look-and-click software execution environment such that software download and installation are internally proceeded in a completely user-transparent way. Therefore, the SOD system relieves the user from the tricky, failure-prone installation business. In addition, the software developer now obtains a new, powerful means to advertise and propagate their software products since the user can use software packages via user-friendly UI window or web browser by look-and-click interactive operation. In the paper, we also make a couple of SOD streaming experiments using a spectrum of popular softwares. Based on the analysis of the experiment results, we also propose two performance improvement schemes.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.257-257
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• 2007

고밀도 FeRAM (Ferroe!ectric Random Access Memory) 소자를 개발하기 위해서는 강유전체 물질을 이용한 안정적인 스텍형의 커패시터 개발이 필수적이다. 특히 $(Bi,La)_4Ti_3O_{12}$ (BLT) 강유전체 물질을 이용하는 경우에는 낮은 열처리 온도에서도 균질하고 높은 값의 잔류 분극 값을 확보하는 것이 가장 중요한 과제 중의 하나이다. 불행히도, BLT 물질은 a-축으로는 약 $50\;{\mu}C/cm^2$ 정도의 높은 잔류 분극 값을 갖지만, c-축 방향으로는 $4\;{\mu}C/cm^2$ 정도의 낮은 잔류 분극 값을 나타내는 동의 강한 비등방성 특성을 보인다. 따라서 BLT 박막에서 각각 입자들의 크기 및 결정 방향성을 세밀하게 제어하는 것은 무엇보다 중요하다. 본 연구에서는 16 Mb의 1T/1C (1-transistor/1-capacitor) 형의 FeRAM 소자를 BLT 박막을 적용하여 제작하였다. 솔-젤 (sol-gel) 용액을 이용하여 스핀코팅법으로 BLT 박막을 증착하고, 후속 열처리 공정을 RTP (rapid thermal process) 공정을 이용하여 수행하였다. 커패시터의 하부 전극 및 상부 전극은 각각 Pt/IrOx/lr 및 Pt을 적용하였다. 반응성 이온 에칭 (RIE: reactive ion etching) 공정을 이용하여 커패시터를 형성시킨 후, 32k-array (unit capacitor: $0.68\;{\mu}m$) 패턴에서 측정한 스위칭 분극 (dP=P*-P^) 값은 약 $16\;{\mu}C/cm^2$ 정도이고, 웨이퍼 내에서의 균일도도 2.8% 정도로 매우 우수한 특성을 보였다. 그러나 단위 셀들의 특성을 평가하기 위하여 bit-line의 전압을 측정한 결과, 약 10% 정도의 커패시터에서 불량이 발생하였다. 그리고 이러한 불량 젤들은 매우 불규칙적으로 분포함을 확인할 수 있었다. 이러한 불량 원인을 파악하기 위하여 양호한 젤과 불량이 발생한 셀에서의 BLT 박막의 미세구조를 분석하였다. 양호한 셀의 BLT 박막 입자들은 불량한 셀에 비하여 작고 비교적 균일한 크기를 갖고 있었다. 이에 비하여 불량한 셀에서의 BLT 박막에는 과대 성장한 입자들이 존재하고 이에 따라서 입자 크기가 매우 불균질한 것으로 확인되었다. 또 이러한 과대 성장한 입자들은 거의 모두 c-축 배향성을 나타내었다. 이상의 실험 결과들로부터, BLT 박막을 이용하여 제작한 FeRAM 소자에서 발생하는 불규칙한 셀 불량의 주된 원인은 c-축 배향성을 갖는 과대 성장한 입자의 생성임을 알 수 있었다. 즉 BLT 박막을 이용하여 FeRAM 소자를 제작하는 경우, 균일한 크기의 입자 및 c-축 배향성의 입자 억제가 매우 중요한 기술적 요소임을 알 수 있었다.

• Journal of Korean Society of Steel Construction
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• v.20 no.1
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• pp.21-31
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• 2008

response surface method (RSM) is widely used to evaluate th e extremely smal probability of ocurence or toanalyze the reliability of very complicated structures. Althoug h Monte-Carlo Simulation (MCS) technique can evaluate any system, the procesing time of MCS dependson the reciprocal num ber of the probability of failure. The stochastic finite element method could solve thislimitation. However, it is limit ed to the specific program, in which the mean and coeficient o f random variables are programed by a perturbation or by a weigh ted integral method. Therefore, it is not aplicable when erequisite programing. In a few number of stage analyses, RSM can construct a regresion model from the response of the c omplicated structural system, thus, saving time and efort significantly. However, the acuracy of RSM depends on the dist ance of the axial points and on the linearity of the limit stat e functions. To improve the convergence in exact solution regardl es of the linearity limit of state functions, an improved adaptive response surface method is developed. The analyzed res ults have ben verified using linear and quadratic forms of response surface functions in two examples. As a result, the be st combination of the improved RSM techniques is determined and programed in a numerical code. The developed linear adapti ve weighted response surface method (LAW-RSM) shows the closest converged reliability indices, compared with quadratic form or non-adaptive or non-weighted RSMs.

• Journal of Chest Surgery
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• v.30 no.6
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• pp.607-612
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• 1997

Between March 1963, and December 1994, fifty-three patients with a ruptured aneurysm of sinus of Vasalva(RSV) were operated. The RSV originated from the right coronary sinus in 43 patients(81%), from the non coronary sinus in 7 patients(13%), and from combined sinuses in 2 patients. The RSV from the right coronary sinus mainly drained to the right ventricle(81.4%), and the RSV from the non coronary sinus mainly drained to the right atrium(71.4%). Recently, we are using patch to repair the RSV through a double approach. During the operation, concomitant . procedures were performed; 32 Patch repairs of VSD, 14 aortic valvuloplasty, 10 aortic valve replacement, 2 tricuspid valvuloplasty, and one Bentall's procedure. During the follow up period between 1 and 31 years(mean 8 years, 94% follow up), there were 2 late deaths and 14 late complications. Actuarial 10-year survival rate .was 95%, and 10-year actuarial freedom from late event was 53 %. Factor analysis revealed that the combined SBE is a risk factor of late event. Actuarial freedom from failure of aortic valvuloplasty was 55% at 9 years. Although surgical repair of RSV achieved excellent long term survival, aortic regurgitation and endocarditis revealed significant risk factor in long-term results. Therefore, more attention should be required in patients of RSV associated with aortic regurgitation or endocarditis.

• Journal of Chest Surgery
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• v.47 no.3
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• pp.255-261
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• 2014

Background: To determine the predictors of clinical outcomes following surgical descending thoracic aortic (DTA) repair. Methods: We identified 103 patients (23 females; mean age, $64.1{\pm}12.3$ years) who underwent DTA replacement from 1999 to 2011 using either deep hypothermic circulatory arrest (44%) or partial cardiopulmonary bypass (CPB, 56%). Results: The early mortality rate was 4.9% (n=5). Early major complications occurred in 21 patients (20.3%), which included newly required hemodialysis (9.7%), low cardiac output syndrome (6.8%), pneumonia (7.8%), stroke (6.8%), and multi-organ failure (3.9%). None experienced paraplegia. During a median follow-up of 56.3 months (inter-quartile range, 23.1 to 85.1 months), there were 17 late deaths and one aortic reoperation. Overall survival at 5 and 10 years was $80.9%{\pm}4.3%$ and $71.7%{\pm}5.9%$, respectively. Reoperation-free survival at 5 and 10 years was $77.3%{\pm}4.8%$ and $70.2%{\pm}5.8%$. Multivariable analysis revealed that age (hazard ratio [HR], 1.10; 95% confidence interval [CI], 1.05 to 1.15; p<0.001) and left ventricle (LV) function (HR, 0.88; 95% CI, 0.82 to 0.96; p<0.003) were significant and independent predictors of long-term mortality. CPB strategy, however, was not significantly related to mortality (p=0.49). Conclusion: Surgical DTA repair was practicable in terms of acceptable perioperative mortality/morbidity as well as favorable long-term survival. Age and LV function were risk factors for long-term mortality, irrespective of the CPB strategy.

• Journal of Trauma and Injury
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• v.21 no.2
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• pp.115-119
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• 2008

Purpose: Abrupt abstinence from alcohol in cause of chronic alcohol addiction can trigger alcohol withdrawal syndrome. The authors studied the effect of post-operative alcohol withdrawal syndrome in patients who require intensive care due to trauma. Methods: For the study group, we selected 70 patients who had undergone emergency surgery from May 2003 to March 2007 due to trauma and who had been treated with prophylactic thiamine. Data was collected retrospectively. We excluded those who extended their hospital stay for other than traumatic causes, those who died within 3 days of surgery after trauma, those who transferred to other institutions, and those who received a psychiatric diagnosis. Patient groups were determined by the existence or the non-existence of withdrawal syndrome. Age, sex, injury mechanism, mortality, complications, durations of hospital stay and intensive care, use of mechanical ventilator, and sedative use were investigated. A Chi-square test and The Mann-Whitney method were used for statistical analysis in this study. Results: Twenty-four (24) patients from the 58 who had an ISS of 16 or more showed alcohol withdrawal syndrome, and men were shown to be affected with the syndrome significantly more than women. Although ISS was higher in the group with alcohol withdrawal syndrome, statistically, the difference was not significant (P<0.08). The total hospital stay in the patient group with alcohol withdrawal syndrome was on average 10 days longer. However, the difference was not significant (P<0.054). The duration of intensive care in the patient group with alcohol withdrawal syndrome was significantly longer (P<0.029). The patients with alcohol withdrawal syndrome showed no significant difference in the duration of mechanical ventilator use (P<0.783), or in the duration of sedative use (P<0.284). Respiratory distress, pneumonia, upper airway infection, sepsis, acute renal failure, and mortality in the alcohol withdrawal syndrome group were investigated, but no statistically significant difference were noted. Conclusion: We found that the duration of intensive care in chronic alcohol abusers was longer due to the development of alcohol withdrawal syndrome. We also discovered that, when the patients overcame the symptoms of alcohol withdrawal syndrome after intensive care, no difference was found in the frequency of developing complications, the morbidity, and the mortality. Therefore, we conclude that intensive care in trauma patients who are chronic alcohol abusers decreases the incidence of complications found in patients with post-operative alcohol withdrawal syndrome and does not adversely impact the prognoses for those patients.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.2
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• pp.227-233
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• 2014

This study investigates the vibration characteristics of a wire-bonding piezoelectric transducer and ultrasonic horn for high-speed and precise welding. A ring-type piezoelectric stack actuator is excited at 136 kHz to vibrate a conical-type horn and capillary system. The nodal lines and amplification ratio of the ultrasonic horn are obtained using a theoretical analysis and FEM simulation. The vibration modes and frequencies close to the driving frequency are identified to evaluate the bonding performance of the current wire-bonder system. The FEM and experimental results show that the current wire-bonder system uses the bending mode of 136 kHz as the principal motion for bonding and that the transverse vibration of the capillary causes the bonding failure. Because the major longitudinal mode exists at 119 kHz, it is recommended that the design of the current wire-bonding system be modified to use the major longitudinal mode at the excitation frequency and to minimize the transverse vibration of capillary in order to improve the bonding performance.