• 한국압력기기공학회 논문집
• /
• 제6권1호
• /
• pp.37-42
• /
• 2010

The stay cylinder weld at the steam generator of Korean Standard Nuclear Power Plants is safety class I component and is subjected to be inspected by the volumetric examination such as ultrasonic method. As accessibility of this area is limited due to the narrow space and high radiation, the existing manual inspection method involves various difficulties. Moreover operators may be exposed to internal contamination by contaminated dust during the surface buffing process to improve the inspection reliability of this area. Recently the new automatic inspection system for stay cylinder welds has been developed. The inspection system basically consists of a driving assembly, data acquisition device and signal processing units. The driving assembly is classified by 1) the scanner for inspecting and buffing the weld, 2) pillars for guiding the scanner and 3) the base frame for loading and supporting pillars. The scanner has 4 sensor modules to inspect in 4 refracted angles and 4 incident directions. These components can be inserted into the skirt of the stay cylinder through the manway hole and assembled easily by one-touch in the skirt. Data acquisition device and signal processing units developed in previous works are also newly upgraded for better processing of data analysis and evaluation. The system has been successfully demonstrated not only in the mock-up but also in the field. In this paper, newly developed inspection system for the stay cylinder weld of the steam generator is introduced and their field applications are discussed.

• 대한본초학회지
• /
• 제22권4호
• /
• pp.145-153
• /
• 2007

Objective : Although chronic non-bacterial prostatitis is a common disease, it is very difficult to treat effectively. Toosendan fructus(TOF) has been traditionally used in treatment of abdominal pain and parasite. In this study, we investigated the therapeutic effects and action mechanism of Toosendan fructus (TOF) in the rat model of non-bacterial prostatitis induced by castration and testosterone treatment. Method : Eight-month-old rats were treated with $17{\beta}$-estradiol after castration for induction of experimental non-bacterial prostatitis, which is similar to human chronic prostatitis in histophatological profiles. Toosendan fructus(TOF) and testosterone were administered as an experimental specimen and a positive control, respectively. The prostates were evaluated by histopahological parameters including the epithelial score and epithelio-stromal ratio for glandular damage. Also, the prostates were observed by hematological alterations of WBC, RBC, hemoglobin, hematocrit and platelet. Results : While prostates of control rats revealed severe acinar gland atrophy and stromal proliferation, the rats treated with Toosendan fructus(TOF) showed a diminished range of the tissue damage. Epithelial score was improved in Toosendan fructus(TOF) than that of the control. The epithelio-stromal ratio was lower in Toosendan fructus(TOF) when compared to that of the control. Also, the examination of bloods were not observed hematological change. Conclusions : These findings suggest that Toosendan fructus(TOF) may protect the glandular epithelial cells and may take hematological safety. We concluded that Toosendan fructus(TOF) may could be a useful remedy agents for treating the chronic non-bacterial prostatitis.

• 대한지하수환경학회지
• /
• 제2권1호
• /
• pp.30-37
• /
• 1995

조석의 영향을 받는 감조구역의 대수층은 감조 하천의 수위에 따라 지하수 수두의 변화가 예상된다. 지하수 수두가 주기적으로 변화하는 대수층에서 지하수를 이용하거나 구조물을 시공하기 위해서는 지하수 수두의 거동을 고려해야 한다. 감조구역에서 지하수 수두에 영향을 미치는 조석의 진폭과 투수계수 등의 변수에 대해서 수치실험을 수행하였다. 수치실험을 위해 1차원 유한차분 모형을 이용하였다. 우선 수치모형의 안정성을 검토하기 위해 해석해와 비교하였다. 그리고 조석의 진폭과 투수계수가 지하수 수두에 미치는 영향에 대해 고찰하고 이 때 지하수의 수리경사가 존재하는 경우와 없는 경우에 대해 수치실험하였다. 또한 감조구역 내에서 양수를 하는 경우에 지하수 수두의 변화 양상을 고찰하기 위해 수치실험을 수행하였다. 본 논문에서 사용된 변수값을 이용하면 영향권은 약 60 m정도인데 이는 한 파장(equation omitted) 내에서 영향권이 설정된다. 조석의 영향을 받는 대수층과 영향을 받지 앎은 대수층에서 일정한 율로 양수하였다. 영향권 내에서 조석의 영향을 받는 대수층의 수두가 크기 때문에 상대적으로 양정고는 작아져 동력비의 절감을 가져올 수 있음을 알았다 그리고 이들의 결과를 이용하면 감조구역에서 오염원의 추적, 지하수의 효율적인 이용, 구조물을 시공할 때 구조물의 안정성과 안전성을 검토하는데 도움이 될 것이다.

• 대한교통학회지
• /
• 제11권1호
• /
• pp.87-103
• /
• 1993

The subject this paper is the signal control strategy under oversaturated conditions. The nature of traffic control for oversaturation is essentially different from the standard control modes. While under non-saturated situation traffic control is needed for the sake of safety and efficiency, the throughput is essential under oversaturated conditions. Therefore berth objective and strategies differ. For an oversaturated stream the cycle time and the signal offset are thought to be of rather secondary importance. For this case the green split may well be the most important control variable to serve the excessive demand. Up to now, however, most efforts have concentrated on the strategy with the concept which lies just on the extension of Webster's. "Green-split Coordination Strategy for Over-Saturated Networks", presents newly contrived three types of strategies named Forward-coordination, Backward-coordination and Network-coordination respectively and describes the algorithms with the evaluations. The forward coordination strategy treats the forward wave of flow between two signals. The aim is to prevent the outbreak of queue due to the accumulation of temporary excess of demand in near-saturation or saturation flow. The backward coordination strategy treats the backward rave of flow between two signals. The goal is to prevent the waste of green time caused by the exit block at the upstream signal. for this purpose a feedback regulation is provided of the upstream green-split so that the inflow-outflow balance is kept zero. The resultant surplus of green time is alloted to other signal stages. Also here the examination is made of the appropriate value of the feedback control parameter. The network coordination strategy is operated to maximize the network throughput in a specific direction applying a bang-bang control at the bottleneck intersection. This is a type of intervenient control for policy reasons. For this strategy the green-split coordinations, particuarly the backward coordination, are essential as the tactical elements. In order to evaluate the preposed strategies those are compared with the latest existing strategy called saturation-degree-ratio control by the simulation experiments in an assumed 4$\times$4 grid network. The results are satisfactory showing a 10-15% reduction in delays and a 15% increase in network capacity.

• 대한한의학회지
• /
• 제21권3호
• /
• pp.99-112
• /
• 2000

Objective: This study was conducted to suggest a proper administration system of the quality of herbal medicine. Methods: Related literature was carefully inspected and discussions among specialists in the field of herbal medicine's growth, production, circulation and administration were conducted. Results: 1. The administration of herbal medicine's quality should be done in each stage of its circulation; growing stage, harvesting stage, importing stage, production stage, quality examination stage, wrapping stage, circulating stage, and administration stage. 2. A safety standard should be established for items, parts and origins of each medicinal herb. A standard for the identification of forged products and objective standards for quality discrimination should also be established. 3. A national system for the training of herbal medicine quality administration personnel and herbal medicine discrimination personnel should be established. A data base of standardized product specimens should be established and a pharmacopoeia of herbal medicine should be published as a standard of quality administration in herbal medicine. 4. Research into the following preliminary areas should be conducted to investigate quality adminstration of herbal medicine: research related to herbal medicine's raw materials and herbal medicinal drugs; quality estimation of raw materials and drugs; quality administration in oriental medical hospitals; herbal medicine administration law; herbal medicine administration organization; herbal medicinal pharmacology; and policy-related research for the quality improvement of domestically grown medicinal herbs. Conclusion: For the proper administration of herbal medicine's quality, governmental support and intensive research among specialists should be done for the supply of good quality medicinal herbs and the improvement of the efficacy of herbal medicine.

• 수산해양기술연구
• /
• 제43권3호
• /
• pp.222-231
• /
• 2007

This paper represents a basic statistical examination on the navigability of ocean-going ship from the point of estimating the time lasting period when propeller racing occurred by using the basic probability theory and the statistics. The propeller racing is one of the most important seakeeping qualities in relation to the safety of the main engine and shafting system. The trend of the racing has been mainly investigated in order to estimate allowable maximum propeller diameter, operation of ocean-going ships, etc.. In those studies, the propeller racing generally and mainly means the situation (propeller exposed) in which the relative motion amplitude between ship hull and wave surface would exceed a depth of point in rotary disk propeller. Therefore, it seems that the magnitude of the amplitude and its exceeding frequency of propeller racing have been examined as a principal subject of study as usual. However, the time during which the amplitude exceeds the depth of point, that is, the propeller exposes in the air, must be also one of most important factor affecting the trend of propeller racing. Then, this paper proposes a new practical method for estimating the time lasting of exposed propeller related to propeller racing in rough-confused seas on the basis of the linear strip theory and the statistics. And, numerical examples of estimating the propeller racing probability are given for four wide ship forms. Finally the usefulness of the proposed method for predicting propeller racing based on the time lasting period is discussed.

• 한국융합학회논문지
• /
• 제3권3호
• /
• pp.21-27
• /
• 2012

본 연구에서는 20대와 30대를 대상으로 성별, 직업별, 모발의 굵기 등 다양한 탈모의 원인들을 통한 자가인식의 정도를 파악하고 이에 따른 두피관리 행위의 실태를 알아보고자 하였다. 본 연구의 자료는 부산 경남지역에 거주하는 20대와 30대 262명을 대상으로 설문조사를 하였으며, 수집된 자료는 SPSS version 12.0을 이용하였다. 연구문제와 관련하여 빈도, 백분율, ${\chi}^2$검정 등을 적용하였다. 이상의 연구 분석 결과로 탈모에 관한 자가인식이 두피관리의 행위요인으로 귀결시킴으로써 연구대상자의 행위정도를 가름할 수 있었다. 이는 20대와 30대에서도 탈모에 관한 자가인식이 높을 수록 두피관리행위 또한 잘 실천하고 있다는 사실을 반영하는 것으로 탈모에 관한 자가인식은 두피관리와 밀접한 관계임을 알 수 있었다.

• 한국지반환경공학회 논문집
• /
• 제8권6호
• /
• pp.13-19
• /
• 2007

본 연구에서는 ${\bigcirc}{\bigcirc}$ 도시철도 ${\bigcirc}$ 호선 ${\bigcirc}$ 공구의 지중 전력구관로 매설공사 후 발생한 합성수지 직관의 파손에 대한 원인을 고찰하기 위하여 문헌연구를 통하여 설계 및 구조해석에 사용된 매개변수를 분석하였다. 그리고 현장조건을 면밀히 분석하고 현장 관로를 모사한 관로의 시험시공 및 물다짐 시험을 수행하였다. 또한, 송전관로의 구조적 안정성과 수치해석을 통한 송전관로 기초지반 침하영향 검토를 수행하였다. 수행결과 물다짐에 의하여 얻을 수 있는 상대밀도는 보통 이상이었으며 시방기준에 의거한 상대다짐도는 양호한 물다짐을 수행할 경우 90%정도의 결과를 얻을 수 있었다.

• 한국환경보건학회지
• /
• 제36권2호
• /
• pp.95-107
• /
• 2010

Hand-washing is one of the major factors in personal hygiene and public health. This study was undertaken to investigate the hygienic behavior of food-service employees, focusing on awareness of hand washing, hand washing practices, and the load of index microorganisms (aerobic plate count, total and fecal coliforms, Escherichia coli, and Staphylococcus aureus) on the hands of food-service employees. A questionnaire survey completed by direct interview, direct observation of restrooms by the researcher and trained observers, and microbiological examination according to the Food Code of Korea were carried out. In the survey, a positive attitude toward hand washing compliance was reported; however, improper hand washing and poor hand hygiene of the food-service employees were seen under direct observation. Significant differences (p<0.05) were found between the questionnaire survey and the direct observations in hand washing compliance after using the toilet, duration of hand washing, use of hand washing agents, use of hand washing tools, washing of different parts of the hands, hand-drying method, temperature of water, and method of turning off the water. Samples taken from employees' hands before washing showed higher levels of bacteria than those taken during work and/or after washing (p<0.05). Poor hand washing practices were indicated by the positive results for total and fecal coliforms, E. coli, and S. aureus on the hands of some food-service employees. This study showed that there is a marked difference between the food-service employees' awareness of hand-washing and their actual hand-washing practices. The poor hand hygiene of and improper hand washing by the food-service employees should be addressed for improved food safety.

• BMB Reports
• /
• 제36권1호
• /
• pp.43-48
• /
• 2003

Understanding the process of carcinogenesis will involve both the accumulation of many scientific facts derived from molecular, biochemical, cellular, physiological, whole animal experiments and epidemiological studies, as well as from conceptual understanding as to how to order and integrate those facts. From decades of cancer research, a number of the "hallmarks of cancer" have been identified, as well as their attendant concepts, including oncogenes, tumor suppressor genes, cell cycle biochemistry, hypotheses of metastasis, angiogenesis, etc. While all these "hallmarks" are well known, two important concepts, with their associated scientific observations, have been generally ignored by many in the cancer research field. The objective of the short review is to highlight the concept of the role of human adult pluri-potent stem cells as "target cells" for the carcinogenic process and the concept of the role of gap junctional intercellular communication in the multi-stage, multi-mechanism process of carcinogenesis. With these two concepts, an attempt has been made to integrate the other well-known concepts, such as the multi-stage, multi-mechanisn or the "initiation/promotion/progression" hypothesis; the stem cell theory of carcinogenesis; the oncogene/tumor suppression theory and the mutation/epigenetic theories of carcinogenesis. This new "integrative" theory tries to explain the well-known "hallmarks" of cancers, including the observation that cancer cells lack either heterologous or homologous gap junctional intercellular communication whereas normal human adult stem cells do not have expressed or functional gap junctional intercellular communication. On the other hand, their normal differentiated, non-stem cell derivatives do express connexins and express gap junctional intercellular communication during their differentiation. Examination of the roles of chemical tumor promoters, oncogenes, connexin knock-out mice and roles of genetically-engineered tumor and normal cells with connexin and anti-sense connexin genes, respectively, seems to provide evidence which is consistent with the roles of both stem cells and gap junctional communication playing a major role in carcinogenesis. The integrative hypothesis provides new strategies for chemoprevention and chemotherapy which focuses on modulating connexin gene expression or gap junctional intercellular communication in the premalignant and malignant cells, respectively.