• Journal of Chest Surgery
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• 제20권2호
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• pp.230-240
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• 1987

Cardioplegia and myocardial protection were performed under cardiopulmonary bypass during open-heart surgery with the use of cold St. Thomas Hospital cardioplegic solution [4=C] for the coronary artery perfusion and normal saline solution [4- C] for the topical cardiac cooling. To maintain the state of myocardial protection, coronary artery reperfusion was carried out using St. Thomas Hospital cardioplegic solution at the interval of 30 minutes. A total number of patients studied were 57 cases, including 37 cases of correction for congenital cardiac anomalies and 20 cases for acquired heart valvular diseases. Cardiopulmonary bypass time during the surgery was observed to be average of 87.89*47.55 hours, aortic cross-clamping time to be average of 76.68~44.27 hours raging from 30 to 191 minutes. In order to evaluate the effects of myocardial protection in the surgery, serum enzyme levels were determined. To observe the relationship between aortic cross-clamping time and myocardial protection effects, patients studied were divided into the following 3 groups. I group: aortic cross-clamping time, 60 minutes, II group: aortic cross-clamping time, 90 minutes, III group: aortic cross-clamping time, over 91 minutes. 1. Changes in serum enzyme levels in postoperative period. [1] SCOT; The postoperative value [increased over 200 units] for ischemic myocardial injury during operation was observed in 11 cases [19.3% of the total] of the total patients studied, of which 4 cases [13.3%] in I group, 1 case [10.0%] in II group, and 6 cases [35.3%] in III group. [2] LDH; The positive value [increased over 900 units] for ischemic myocardial injury during operation was observed in 9 cases [15.7% of the total] of the total patients studied, of which 2 cases [6.6%] in I group, 1 case [10.0%] in II group, and 6 cases [35.3%] in III group. [3] CPK; The positive value [increased over 800 units] for ischemic myocardial injury during operation was observed in 10 cases [17. 5% of the total] of the total patients studied, including 4 cases [13. 3%] in I group, 1 case [10.0%] in II group, and 5 cases [29.4%] in III group. 2. The myocardial protection method used in the present study was demonstrated to be effective for the myocardial protection in the surgery with aortic cross-clamping time of up to 90 minutes. A few ischemic myocardial injury were observed in the surgery with aortic cross-clamping time over 91 minutes, but no significant cardiac dysfunction was noted. The surgery with aortic cross-clamping time of up to 191 minutes did not appear to give rise any significant interference with postoperative recovery.

• 한국정보통신학회논문지
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• 제17권3호
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• pp.678-684
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• 2013

본 논문에서는 SAW 필터가 없는 LTE-Advanced RF 송신기에 적용 가능한 기저대역 송신단 회로를 제안한다. 제안하는 기저대역 송신단 회로는 Tow-Thomas구조의 2차 능동 저역통과 필터 1개와 1차 수동 RC 필터 1개로 구현되었으며, 0.7 MHz, 1.5 MHz, 2.5 MHz, 5 MHz, 7.5 MHz, 10 MHz, 그리고 20 MHz의 총 7개의 채널 차단 주파수를 제공하며, 각 채널 별로 -41 dB에서 0 dB까지 1-dB 단계로 이득 조절이 가능하다. 제안하는 2차 능동 저역 통과 필터 회로는 DC 소모 전류 효율을 높이기 위해 채널 차단 주파수를 세 그룹으로 나누어서 선택된 차단 주파수 그룹에 따라 연산증폭기의 전류 소모를 3단계로 가변 할 수 있도록 연산증폭기 내부에 3개의 단위-연산증폭기(OTA)를 병렬로 연결하여 선택적으로 사용할 수 있도록 설계하였다. 또한, 제안하는 연산 증폭기는 저전력으로 1-GHz UGBW(Unit Gain Bandwidth)를 얻기 위해 Miller 위상 보상 방식과 feed-forward 위상 보상 방식을 동시에 사용하였다. 제안하는 기저대역 송신기는 65-nm CMOS 공정을 사용하여 설계되었고 1.2 V의 전압으로부터 선택된 채널 대역폭에 따라 최소 6.3 mW, 최대 24.1 mW의 전력을 소모한다.

• 한국콘텐츠학회논문지
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• 제15권5호
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• pp.151-167
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• 2015

한국 영화의 시장 점유율은 최저 2008년 42.1%에서 최고 2013년 59.7%로 높은 점유율을 유지하고 있다. 그러나 멀티플렉스와 와이드 릴리스 전략, 4대 메이저 배급 회사와 3대 멀티플렉스 체인의 독과점의 영향으로 한국 영화 흥행의 양극화 현상은 심화되고 있다. 한국 영화 흥행 집중도는 2004년 0.53에서 2014년 0.85로 심화되었다. 흥행 순위 상위 10%의 한국 영화가 차지하는 관객 수 비중은 2004년 30.28%에서 2014년 71.2%로 급격히 높아진 반면에, 흥행 순위 하위 50%는 2004년 11.03%에서 2014년 0.08%로 아주 낮아졌다. 상영 스크린 집중도도 2004년 0.36에서 2014년 0.67로 심화되었고, 상영 횟수 집중도도 2004년 0.46에서 2014년 0.78로 높아졌다. 좌석 수의 집중도도 2004년 0.50에서 2014년 0.79이다. 많은 관객이 선택하는 영화라서 상영 스크린 수를 늘리고, 상영 횟수를 늘리고, 많은 좌석 수를 확보한다면, 이는 자연스러운 시장의 선택 결과라고 하겠다. 하지만 이들 영화들의 좌석 점유율 집중도를 보면 그렇지 않음을 알 수 있다. 좌석 점유율 집중도는 2004년 0.22에서 2014년 0.38로 다른 집중도와는 달리 완만한 증가세를 유지하고 있다. 상위 10% 영화들의 좌석 점유율은 2004년 38.2%에서 2014년 32.3%이며, 하위 50%는 2004년 23.5%에서 2014년 23.8%로 나타났다.

• Archives of Plastic Surgery
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• 제45권2호
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• pp.180-184
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• 2018

Breast deformity, in post-burn patients, is a common problem leading to lower self-esteem and reclusive behavior that impairs quality of life. The authors present the course of treatment of an 18-year-old immigrant girl who suffered second- to third-degree burns over approximately 20% of her total body surface area in her early childhood. The second- to third-degree burns were located on her right trunk and abdomen, as well as her right shoulder, neck, and right groin area. Since it was not offered in her home country, reconstructive surgery, including microsurgical breast reconstruction, was sought abroad. Due to the lack of available skin and soft tissue, a bilateral breast reconstruction with free transverse myocutaneous gracilis flaps was offered. This case illustrates one method of using microsurgery to address post-burn breast deformities in order to alleviate psychological suffering and improve quality of life.

• Nuclear Engineering and Technology
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• 제49권7호
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• pp.1423-1430
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• 2017

Detonation cell width is an important parameter in hydrogen explosion assessments. The experimental data on gas detonation are statistically analyzed to establish a universal method to numerically predict detonation cell widths. It is commonly understood that detonation cell width, ${\lambda}$, is highly correlated with the characteristic reaction zone width, ${\delta}$. Classical parametric regression methods were widely applied in earlier research to build an explicit semiempirical correlation for the ratio of ${\lambda}/{\delta}$. The obtained correlations formulate the dependency of the ratio ${\lambda}/{\delta}$ on a dimensionless effective chemical activation energy and a dimensionless temperature of the gas mixture. In this paper, support vector regression (SVR), which is based on nonparametric machine learning, is applied to achieve functions with better fitness to experimental data and more accurate predictions. Furthermore, a third parameter, dimensionless pressure, is considered as an additional independent variable. It is found that three-parameter SVR can significantly improve the performance of the fitting function. Meanwhile, SVR also provides better adaptability and the model functions can be easily renewed when experimental database is updated or new regression parameters are considered.

• International Journal of Concrete Structures and Materials
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• 제7권1호
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• pp.71-78
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• 2013

Prestressed concrete (PC) is the predominant material in highway bridge construction. The use of high-strength concrete has gained wide acceptance in the PC industry. The main target in the highway industry is to increase the durability and the life-span of bridges. Cracking of elements is one aspect which affects durability. Recently, nine 7.62 meter long PC I-beams made with different concrete strength were designed according to a simple, semi-empirical equation developed at the University of Houston (UH) (Laskar et al., ACI Journal 107(3): 330-339, 2010). The UH Method is a function of shear span-to-depth ratio (a/d), concrete strength $\sqrt{f^{\prime}_c}$, web area $b_wd$, and amount of transverse steel. Based on testing these girders, the shear cracking strength of girders with different concrete strength and different shear span-to-depth ratio was investigated and compared to the available approaches in current codes such as ACI 318-11 (2011) and AASHTO LRFD Specifications (2010).

• Advances in materials Research
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• 제1권3호
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• pp.191-204
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• 2012

In this paper, we report on the obtention of nanocrystalline $SrMoO_4$ synthesized through modified combustion process. These powders were characterized by X-ray diffraction, Fourier Transform Raman and Infrared Spectroscopy. These studies reveal that the scheelite-type $SrMoO_4$ crystallizes in tetragonal structure with I41/${\alpha}$ (N#88) space group. Transmission electron microscopy image shows that the nanocrystalline $SrMoO_4$ powders have average size of 18 nm. The optical band gap determined from the UV-V is absorption spectra for the as prepared sample is 3.7 eV. These powders showed a strong green photoluminescence emission. The samples are sintered at a relatively low temperature of $850^{\circ}C$. The morphology of the sintered pellet is studied with scanning electron microscopy. The dielectric constant and loss factor values obtained at 5 MHz for a well sintered $SrMoO_4$ pellet has been found to be 9.50 and $7.5{\times}10^{-3}$ respectively. Thus nano $SrMoO_4$ is a potential candidate for low temperature co-fired ceramics and luminescent applications.

• Journal of Microbiology and Biotechnology
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• 제28권11호
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• pp.1782-1790
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• 2018

Assessment of microorganism viability is useful in many industrial fields. A large number of methods associated with the use of fluorescent probes have been developed, including fluorimetry, fluorescence microscopy, and cytometry. In this study, a microvolume spectrofluorometer was used to measure the membrane potential variations of Escherichia coli. In order to estimate the sensitivity of the device, the membrane potential of E. coli was artificially disrupted using an ionophore agent: carbonyl cyanide 3-chlorophenylhydrazone. The membrane potential was evaluated using two ratiometric methods: a Rhodamine 123/4',6-diamidino-2-phenylindole combination and a JC-10 ratiometric probe. These methods were used to study the impact of freezing on E. coli, and were compared with the conventional enumeration method. The results showed that it was beneficial to use this compact, easy-to-use, and inexpensive spectrofluorometer to assess the viability of bacterial cells via their membrane potential.

• Journal of Chest Surgery
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• 제27권7호
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• pp.603-609
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• 1994

Esophageal atresia is a rare congenital anomaly and it usually associated with tracheo-esophgeal fistula and other congenital anomalies. The first report of esophageal atresia with tracheo-esophageal fistula was done by Thomas Gibson in 1696. In 1941, Haight performed the first successful primary anastomosis for esophageal atresia. These accomplishments opened the gateway for clinical studies that have resulted in reinforcements and improvement in the care of infants born with this anomaly. From January 1986 to April 1994, 14 cases of esophgeal atresia with tracheo-esophgeal fistula were diagnosed in Kyung Hee Uinv. Hospital. There were 9 male and 5 female infants. 12 infants were Gross classification type C and 2 infants were type A. The average body weight was 2.7$\pm$0.4kg and Waterson Category A contained 4 infants, B contained 3 infants and C contained 7 infants. Among these infants, 9 infants were underwent anastomosis procedures. We performed retropleural approach in 6 infants, transpleural approach in 2 infants and 1 infant was performed colon interposition through substernal space.By the method of anastomosis, end-to-side anastomosis was performed in 5 infants, end-to-end anastomosis in 3 infants and esophagocologastrostomy in 1 infant.The former 8 infants were Gross classification type C and the latter was type A. Among the type C infants, 6 infants were anastomosed with one layer interrupted suture and 2 infants with 2 layer interrupted suture. Post- operative death was in 1 infant and 8 infants were discharged with good result and have been in good condition.

• 한국신뢰성학회지:신뢰성응용연구
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• 제5권2호
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• pp.241-259
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• 2005

The environmental problem is a main subject of the 21C and an environment destruction phenomenon by various kinds of environmental materials is reaching serious level. Nations to be classified as the environmental developed country, are born again environmental rich country. And they earn a large income by trade Every kind environmental resource in an international commercial transaction. Especially, the study that a reliability assessment method to prevent to reliability problem to be happened when the solder lead(lead-free solder), non-cd component, non-bromide component(without the polybrominated biphenyls(PBB) and polybrominated diphenyl ethers(PBDE))and hexavalent chromium(Cr VI) clearance component and mercury-free applied to electronic equipment is progressed. As the result of the study for applying of a reliability assessment technique of lead-free solder that recognized the most of urgent problem at the company, combination accelerated life test could taken by adding and appling the part of a humidity acceleration part to Eyring Model which is proposed by R.E.Thomas. The reliability assessment methods study of PWB clean environmental materials is expected to respond to a reliability elevation and environmental material regulation policy spreading all over the world by beginning form Europe.