• 교육시설 논문지
• /
• 제18권6호
• /
• pp.45-56
• /
• 2011

This study explored what impacts can be brought to students, teachers, schools, and community by the improvement of physical environment of school spaces. For the purpose, we studied 5 schools (2 elementary and 3 middle schools) who took part in the Happy School Project funded by the Ministry of Culture, Sports, and Tourism in 2008. Ten series of Focus Group Interviews were carried out with a sample of 28 students and 20 teachers who experienced both before and after the school renovation project. The analysis of the interview data revealed that although the project was concerned with a part of school space such as restroom or reading room, it could bring multiple effects such as following: First, the students addressed that they felt "good" about school environment, which led them to feel good about their "schools." This change was found out to bring about more positive attitudes towards a school in general, public manners, peer relationships, emotional well-being, and learning. Second, the teachers became to value more their principals' leadership, being more satisfied with their work environment and more concerned about management of school facilities, and happier with students in terms of teaching and guidance than before. Third, all the 5 schools seem to go through a noticeable change in terms of a school climate and ethos in a more positive and harmonious way. Finally, 'spread', 'promotion', and 'openness' effects were discussed with regard to the relationships between the schools and local community.

• 한국정보과학회논문지:시스템및이론
• /
• 제31권10호
• /
• pp.575-587
• /
• 2004

본 논문은 여러 분야에서 활용될 수 있는 향상된 고속 Expectation-Maximization(FEM) 알고리즘을 제안한다. 첫째, EM의 초기값 설정의 방법으로 많이 사용되고 있는 클러스터링 기법인 K-means의 문제점을 해결하여 개선된 EM의 초기값 선정에 적용하였다. 이것은 기존 K-means 알고리즘에서 임의로 지정하던 랜덤한 초기값 선정을, 데이타 분포 특성을 이용한 균등 분할법을 사용하여 EM의 초기값 문제를 해결하였다. 둘째, EM 과정의 핵심을 이루는 후행 확률(Posterior)의 의미를 부각하여 최대 가능성 후행 확률(Maximum Likelihood Posterior: MLP)과정을 적용하였다. 최종적으로, 본 논문에서 제안한 고속 EM알고리즘(FEM)은 근본적으로 해결하기 못했던 기존의 EM 초기치 선정과 수렴에 대한 문제점을 개선함으로써, EM 알고리즘의 특성을 극대화하는 방향으로 상대적으로 마른 수렴과 향상된 결과를 가져온다. 제안된 알고리즘의 객관적 타당성을 위해 기존의 방법과 제안된 방법에 의한 시뮬레이션의 결과를 여러 데이타들을 가지고 비교 분석하여 제안한 알고리즘의 우수성을 입증하였다.

• 한국안광학회지
• /
• 제1권1호
• /
• pp.29-39
• /
• 1996

Triplet 카메라 렌즈계(f'=50mm, f/3.5)를 통하여 고유값의 중간값은 최적의 감쇠 계수임과, 정규 방정식을 풀 때 SVD 직교화 방법을 적용하면 불량 조건을 제거하여 계산의 정확도를 높일 수 있어서 merit 함수는 최소값에 안정하면서도 빠르게 수렴할 수 있다는 것을 조사하였다. 양호 조건인 triplet 카메라 렌즈계에서 SVD 직교화 방법을 적용한 DLS 법에서 얻은 최소 merit 함수는 가우스 소거법에서 얻은 최소 merit 함수의 97.86%로서 크게 개선되지는 못하였다. 따라서 SVD 직교화 방법을 적용한 DLS 법이 가우스 소거법을 적용한 DLS 법보다 감쇠 계수 적용에 대한 안정성과 수렴속도가 좋으며, 최적화 방법에 적절한 감쇠 계수를 적용시켜주면 최적화 과정의 수렴 속도가 개선됨을 알 수 있었다.

• 방송공학회논문지
• /
• 제12권1호
• /
• pp.41-52
• /
• 2007

다시점 비디오의 일반적인 형태인 3차원 방송 서비스는 최근 많은 관심을 받고 있다. 그렇지만 3차원 방송의 성공을 위해서는 상용 가능한 컨텐츠의 개발, 사용의 용이성, 방송 품질 개선, 비용 절감 등의 과제가 남아있다. 본 논문은 이러한 과제들 중 방송 품질 개선 측면, 특히 인간 요소를 고려한 주관적 화질 개선을 중심으로 접근하여 양안식 영상과 다시점 영상에 적합한 비대칭 코딩 방법을 설명하고 최적의 주관적 화질을 유지하는 비대칭 율의 정량적인 값을 제안한다. 또한 저화질의 2차원 영상들의 경계선들이 3차원 영상의 인지에 미치는 영향을 실험적으로 분석하고 경계선 왜곡의 문제점을 주관적 화질 측면에서 개선하는 경계선 보호 알고리듬을 제안한다. 실험 결과를 통해 기존의 부호화 방법보다 주관적 화질을 개선시킴을 확인하였다.

• Transactions on Electrical and Electronic Materials
• /
• 제14권3호
• /
• pp.160-163
• /
• 2013

We investigated the effect of light intensity and wavelength of a solar cell device by using photoconductive atomic force microscopy (PC-AFM). The $POCl_3$ diffusion doping process was used to produce a p-n junction solar cell device based on a Poly-Si wafer and the electrical properties of prepared solar cells were measured using a solar cell simulator system. The measured open circuit voltage ($V_{oc}$) is 0.59 V and the short circuit current ($I_{sc}$) is 48.5 mA. Also, the values of the fill factors and efficiencies of the devices are 0.7% and approximately 13.6%, respectively. In addition, PC-AFM, a recent notable method for nano-scale characterization of photovoltaic elements, was used for direct measurements of photoelectric characteristics in local instead of large areas. The effects of changes in the intensity and wavelength of light shining on the element on the photoelectric characteristics were observed. Results obtained through PC-AFM were compared with the electric/optical characteristics data obtained through a solar simulator. The voltage ($V_{PC-AFM}$) at which the current was 0 A in the I-V characteristic curves increased sharply up to 1.8 $mW/cm^2$, peaking and slowly falling as light intensity increased. Here, $V_{PC-AFM}$ at 1.8 $mW/cm^2$ was 0.29 V, which corresponds to 59% of the average $V_{oc}$ value, as measured with the solar simulator. Also, while light wavelength was increased from 300 nm to 1,100 nm, the external quantum efficiency (EQE) and results from PC-AFM showed similar trends at the macro scale, but returned different results in several sections, indicating the need for detailed analysis and improvement in the future.

• Journal of Electrical Engineering and Technology
• /
• 제10권4호
• /
• pp.1700-1711
• /
• 2015

In the last decade it has been witnessed significant developments in the area of nano particles and nano scale fillers on electrical, thermal, and mechanical properties of polymeric materials such as resins, varnishes, enamel and bakelites. The electric and thermal properties were more important in the electrical equipments for both steady state and transient state conditions. This paper deals with the characterization of the electric and thermal properties of the pure varnish and zirconia (ZrO₂) filler mixed varnish. The electric properties such as dielectric loss (tan δ), dielectric constant (ε), dielectric strength and partial discharge voltage were analyzed and detailed for different samples. It was observed that zirconia nano filler mixed varnish has the superior dielectric and thermal properties when compared to those of standard varnish. It has shown that at power frequency the 1wt% nano composite sample has the higher permittivity value when compared to other samples. It has been examined that the 1wt% sample was having higher inception and extinction voltages when compared to other samples. It has been observed that 1wt% sample has higher dielectric strength when compared with other samples. There has been an improvement of thermal property by adding few weight percent of zirconia nano fillers. There was not much variation in glass transition among the nano mixed composites. The weight loss was improved at 1wt% of the zirconia nano fillers.

• 한국실내디자인학회논문집
• /
• 제27권1호
• /
• pp.156-164
• /
• 2018

This study analyzed the characteristics of Physical Environment of existing free shuttle bus Interior centered on elderly people who frequently use free shuttle buses. The purpose of this study is to provide basic data that can be used for improvement of existing free shuttle buses. In the case of the old type, in terms of accessible design, the middle entrance is not normally opened except the wheelchair occupant, so that the entrance of the front wheel is always used. Therefore, most elderly people go to the back seat and travel distance is twice longer. In addition, many stairs caused frequent inconveniences for boarding. In the case of the new type, it is planned to be a low-floor type, and various types of safety rods and handles, pictograms for enhancing the information convenience are well-equipped, and the measured value of the overall design characteristic is high. However, in the case of mental stability, it was confirmed that the seat of the bus is colored with a cold color system and is in a different relationship with the warm color which can feel mental stability. Overall, both old and new shuttle buses lack audiovisual feedback on bus routes and route guidance in terms of Supportive design. Also, since the cleaning tools and other miscellaneous items were left in the room, it became an obstacle to space utilization in terms of adaptable design. In terms of safety, both shuttle buses did not come into view with fire extinguishers shaded by miscellaneous items. Therefore, immediate action is unlikely in case of emergency. This problem should be resolved quickly.

• 동의생리병리학회지
• /
• 제16권4호
• /
• pp.823-829
• /
• 2002

The thrombosis importantly came to the front as the risk factor of these circulation system's disease. SilsoSanGami(SSG) was used for investigating the inhibitory effect on platelet-activating factor-induced platelet aggregation about drugs that used to improvement various symptoms created by the thrombosis in oriental medicine. In this study, the water-extracted SSG was investigated for its possible antithrombotic action on platelets. The antithrombotic activity of water-extracted SSG was deduced from its ability to suppress platelet aggregation, ATP-exocytosis, and the generation of prostaglandin E₂ and thromboxane A₂ by human platelets, stimulated with arachidonic acid. Water-extracted SSG dose-dependently suppressed the aggregation of human platelets, the release of endogenous ATP, and the formation of PGE₂ and TXB₂, both the latter usually detected to estimate the activity of COX and TXS, respectively. Since the IC/sub 50/ values necessary to inhibit COX (115 ㎍/㎖ SSG) and TXS(74 ㎍/㎖ SSG) were in the same range, inhibition of COX is suggested to be the primary target of water-extracted SSG, thus suppressing the formation of PGE₂ which is metabolized by TXS to TXA₂. We considerated that SSG has practical applicational value of clinical trial in the thrombosis caused by platelet aggregation.

• 대한예방한의학회지
• /
• 제20권2호
• /
• pp.77-86
• /
• 2016

Objectives : This study aims to investigate the current situation of domestic patents in Korea on natural products and to provide directions for developing and applying herbal medicinal products by in-depth analyses. Methods : Combinations of words, such as "A61K" or "A61P", "herb" or "Korean medicinal herb" or "Korean medicine" or "traditional" or "natural" or "$botanic^*$" or "China", and "medicine" or "treatment" or "prevention" or "improvement", were used to search patents in the World Intellectual Property Service (WIPS) database. Three methods were applied to analyze natural products patents. First, the number of patent registrations was sorted by year. Second, the assignees were analyzed by count and country of origin. Finally, cluster map analysis was conducted to explore frequently emerging words in natural products and the relationship amongst those words to treat corresponding diseases/technologies. Results : Results showed that, first, the total number of patents had been increasing. Among the patents, 76.4% were registered by domestic institutes/companies, and 23.6% by foreign institutes/companies. Second, USA, Japan, and China possess a considerable number of Korean patents and, therefore, domestic institutes/companies can seek joint technological development opportunities with their counterparts from those countries in the future. Finally, a total of four clusters were identified by cluster map analysis. Each of the clusters includes natural products related to diseases involving skin, aging, and blood sugar, as well as adult diseases. Conclusions : In this study, natural products patents registered in the Korean Intellectual Property Office were analyzed. The analyses results showed the kinds of natural products that had been employed for the treatment of certain diseases. However, natural products included in existing patents were minimal given that 4,174 species of indigenous plants are found in Korea. Thus, Korean institutes/companies should utilize unexplored plants to develop more value-added drugs.

• Journal of Chest Surgery
• /
• 제17권3호
• /
• pp.409-417
• /
• 1984

In the early days of open heart surgery, acute respiratory failure following extracorporeal circulation was a significant deterrent to an uncomplicated recovery. Although a marked improvement in prevention and treatment of postoperative respiratory failure has been achieved, the problem has not been completely eliminated and continues to be a causative factor in morbidity and mortality Fates following open heart surgery. We have attempted to evaluate postoperative respiratory failure in patients undergoing cardiac operation with the aid of extracorporeal circulation. Our series comprised 92 patients who underwent elective open heart surgery at the Department of Thoracic and Cariodvascular Surgery, School of Medicine, Kyungpook National University, from January, 1980 to December, 1982. In our study, the overall incidence of acute respiratory failure following open heart surgery was 18.8 percent. The duration of extracorporeal circulation in a series of 18 patients who developed postoperative respiratory failure [Group B] was longer in the mean value [120.3 minutes] than the uncomplicated 74 patients [Group A] [85.8 minutes]. The duration of artificial ventilation after open heart surgery in Group A averaged 13.4 hours as contrasted with 76.5 hours in Group B. In Group B, the inspired oxygen concentration [FiO2] in artificial ventilation was continued in the higher level than Group A until 18 hours after operation. Upon pulmonary function test performed pre-and postoperatively, residual volume[RV], RV/TLC and FEV 1.0/FVC were remained essentially unchanged following extracorporeal circulation, whereas forced vital capacity [FVC], FEV 1.0 and FEF 25-75% were significantly decreased in the early postoperative days. The incidence of acute respiratory failure was significantly higher in a series of patients who developed postoperative complications, such as re- exploration due to massive bleeding, low cardiac output, acute renal failure and arrhythmias. A total of 9 patients died, giving an overall mortality was 33.3 percent whereas the mortality was only 1.1 percent for patients without respiratory failure.