• Journal of agriculture & life science
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• v.50 no.1
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• pp.273-281
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• 2016

In this study, after carrying out a bending test that targeted the frames of plastic film greenhouse, the load-displacement relationship was analyzed to be used as basic data to develop greenhouse construction and maintenance guidelines. As a result, regardless of the shapes of the specimen, the yield and the maximum load increased as the size of the specimen increased. The displacement also showed the same pattern. A steel pipe showed lower yield and maximum load than a square pipe, and the displacement was large. In the steel pipe case, the displacement under the yield and maximum load was in the range of approximately 1.42-4.20mm and 5.80-24.13mm, respectively. In the square pipe case, the displacement under the yield and maximum load was in the range of approximately 1.62-3.00mm and 3.13-8.01mm, respectively. Further, a large difference was observed between the result of this test and the values calculated by a conventionally provided standard. In particular, not much difference was found from the result of this test in the case of a purlin member from the values provided by previous researches. However, a large difference was observed in the column or main rafter members. Furthermore, when a wide-span and venlo type, which is a glasshouse, was used as a target(h/100 and h/80), the displacement under the yield and maximum load was approximately 28.0mm and 35.0mm, respectively, which showed a large difference compared with the Netherlands standard(14.0mm) of a glasshouse. Further, in the main rafter case, a large difference was observed in the displacement limit according to the width(i.e., span) of the greenhouse where members are used. Therefore, because the displacement limit can vary depending on various factors such as type, form, and size of a greenhouse, we determined that studies or tests that consider these factors should be carried out to reflect them in the construction and maintenance of greenhouses.

• Nuclear Engineering and Technology
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• v.55 no.6
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• pp.2335-2347
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• 2023

As medical facilities are usually built at urban areas, special concrete aggregates and evaluation methods are needed to optimize the design of concrete walls by balancing density, thickness, material composition, cost, and other factors. Carbon treatment rooms require a high radiation shielding requirement, as the neutron yield from carbon therapy is much higher than the neutron yield of protons. In this case study, the maximum carbon energy is 430 MeV/u and the maximum current is 0.27 nA from a hybrid particle therapy system. Hospital or facility construction should consider this requirement to design a special heavy concrete. In this work, magnetite is adopted as the major aggregate. Density is determined mainly by the major aggregate content of magnetite, and a heavy concrete test block was constructed for structural tests. The compressive strength is 35.7 MPa. The density ranges from 3.65 g/cm³ to 4.14 g/cm³, and the iron mass content ranges from 53.78% to 60.38% from the 12 cored sample measurements. It was found that there is a linear relationship between density and iron content, and mixing impurities should be the major reason leading to the nonuniform element and density distribution. The effect of this nonuniformity on radiation shielding properties for a carbon treatment room is investigated by three groups of Monte Carlo simulations. Higher density dominates to reduce shielding thickness. However, a higher content of high-Z elements will weaken the shielding strength, especially at a lower dose rate threshold and vice versa. The weakened side effect of a high iron content on the shielding property is obvious at 2.5 µSv=h. Therefore, we should not blindly pursue high Z content in engineering. If the thickness is constrained to 2 m, then the density can be reduced to 3.3 g/cm³, which will save cost by reducing the magnetite composition with 50.44% iron content. If a higher density of 3.9 g/cm³ with 57.65% iron content is selected for construction, then the thickness of the wall can be reduced to 174.2 cm, which will save space for equipment installation.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.216-217
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• 2022

Gulpur 수력발전 프로젝트는 전력난을 겪고 있는 파키스탄에 102 MW 규모의 수력발전소를 건설하여 30년 동안 운영 관리한 후 파키스탄 정부로 양도하는 IPP(Independent Power Producing) 형식의 투자사업이다. 남동발전과 DL E&C, 롯데건설이 Sponsor로서 출자한 자본금과, ADB, IFC, K-EXIM 등의 대주단로부터의 차입금을 재원으로 하여 소요 사업비를 조달하고 사업을 개발하였다. DL E&C와 롯데건설이 EPC(Engineering, Procurement, Construction)를 수행하였고, 이산이 Design consultant의 역할을 수행하였다. Gulpur 수력발전 프로젝트의 발전형식은 수로식(run-of-river)으로 201 m³/s의 발전유량과 102 MW의 발전 시설용량을 이용하여 연평균예상발전량은 398 GWh이다. 주요 구조물로는 설계 재현빈도 1년의 유수전환시설(가물막이댐 & 가배수터널)과 콘크리트 중력식댐(H 67 m, L 205 m), 도수터널(D 6.7 m, L 215 m, 2기), 옥외형 발전소 (H 51 m, W 60 m, L 38 m, Kaplan 2기)가 있으며, 2015년 10월 착공하여 2020년 3월 상업발전을 시작하였다. 본 프로젝트는 DL E&C의 첫 번째 EPC 해외수력발전 프로젝트이다. 따라서 프로젝트의 성공적 수행을 위한 경제적 설계, 시공의 효율성 및 안정성 확보 등을 위하여 많은 연구를 수행하는 과정에서 다양한 기술 개선을 이룰 수 있었다. 본고에서는 Gulpur 프로젝트를 통하여 도출된 성공 사례들을 소개 및 공유하고자 한다. 첫 번째로 콘크리트 중력식댐 시공을 위한 유수전환시설의 최적 설계빈도를 산정하였다. 일반적으로 유수전환시설의 규모는 설계기준에 제시된 설계 재현빈도를 이용하는데, 해외 설계기준에서는 10년, 국내 설계기준에서는 1~2년으로 다르게 제시되어 있는 문제점이 있다. 유수전환시설의 규모는 프로젝트의 경제성에 큰 영향을 미치기 때문에 최적 설계빈도의 결정이 필요하며, 위험도분석기법(Risk Analysis)과 기대화폐가치법(Expected Monetary Value)을 이용하여 유수전환시설의 최적 설계 재현빈도와 이에 영향을 미치는 인자를 분석하였다. 위험도는 몬테카를로 시뮬레이션으로 산정된 가물막이댐 파괴확률과 재현빈도를 이용하여 산정된 가물막이댐 월류확률을 고려하였으며, 비용 및 피해액으로는 유수전환시설의 공사비, 가물막이댐 파괴시의 재건설비용과 지체보상금, 가물막이댐 월류시의 복구비용을 고려하였다. 이에 대한 연구결과로, 유수전환시설의 사용기간과 월류시의 복구비용이 유수전환시설의 설계 재현기간 결정에 가장 큰 영향을 미치는 것으로 나타났고, 특히 월류시의 복구비용이 작을수록 낮은 설계 재현빈도를 선택하는 것이 타당한 것으로 나타났다. 예를 들어, 유수전환시설의 사용기간이 3 ~ 5년, 복구비용이 0.5 ~ 1.0 mil USD 이하인 조건에서 가물막이시설의 최적 설계빈도는 1년 ~ 2년인 것으로 나타났다. 또한, 유수전환시설의 사용기간은 본댐의 규모와 시공기간 등을 고려하여 결정되는 사항으로 설계자가 임의 조정할 수 없지만, 복구비용은 시공 관리자에 따라 결정되는 부분으로, 적극적 홍수 피해 저감 및 복구방안을 마련하는 것이 프로젝트의 경제성을 향상시킬 수 있다는 것을 알 수 있었다. 두 번째로 프로젝트의 경제성 향상, 홍수기 댐 시공시의 안전성 확보를 위하여 홍수 조기경보시스템(Early Warning System)을 개발 및 활용하였다. 수로식(Run-of-river) 수력발전댐은 대부분 산악지역에 위치하기 때문에 국지성 강우 및 급한 지형 경사로 인하여 돌발홍수(flash flood)의 발생 가능성이 높다. 따라서 시공 중 홍수(월류) 발생을 미리 감지하고 현장에 전파할 수 있는, 수로식(Run-of-river) 수력발전댐 현장을 위한 홍수 조기경보시스템이 필요하며, 이를 리스크 인식, 모니터링 및 경보, 전파 및 연락, 반응 능력 향상의 4가지 부분으로 나누어 구축하였다. 리스크 인식 부분에서는 가물막이댐 월류 발생 상황에 대한 위험도, 취약성, 리스크를 제시하였으며, 모니터링 및 경보 부분에서는 상류 측정수위에서 유도된 현장 예상수위와 실제 현장 측정 수위를 대상으로 경보홍수위와 위험홍수위로 나누어 관리하였다. 전파 및 연락 부분에서는 현장 시공 조직을 활용하여 홍수시를 대비한 비상연락체계도(Emergency communication flow chart)를 운영하였으며, 반응 능력 향상을 위해 비상연락체계도의 팀별 Action plan을 상세화 하였다. 세 번째로 현장의 지질특성과 50여 차례 발파시험으로 현장 고유의 발파진동감쇄곡선을 도출하였으며, 이를 통해 현장의 시공성과 콘크리트 품질 확보를 동시에 달성할 수 있는 방안을 제시하였다. 콘크리트댐 공사에서는 제한된 공기 내에 공사를 완료하기 위해 사면부 굴착과 콘크리트 타설이 동시에 수행될 수밖에 없는 문제점을 가지고 있다. 그러나 신규 콘크리트 타설면 근처에서 발파를 수행하는 경우 발파로 발생되는 탄성파가 일정 수준을 초과하게 되면, 콘크리트 양생에 영향을 주게 된다. 따라서 다수의 현장 발파시험을 통해 발파거리와 최대진동속도의 상관관계 즉, 발파진동감쇄곡선을 도출함으로써 현장의 발파진동특성을 도출할 수 있었다. 또한, 기존 연구 논문들을 통해 콘크리트 재령기간 별 안전진동속도를 선정하고, 해당 안전진동속도를 초과하지 않는 범위에서 콘크리트 타설면과 발파위치의 거리에 따라 1회 발파 가능한 장약량을 산정하여 적용하였다. 이와 같은 체계적인 접근을 통해 콘크리트 타설과 발파 작업 동시 수행에 대한 논란을 해소할 수 있었다.

• The Korean Journal of Zoology
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• v.18 no.2
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• pp.51-60
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• 1975

The present study was performed histologically and histochemically to observe the cutaneous mucous glands in the frog, Rana nigromaculata during metamorphosis. The cutaneous thssues including dermal plicae in the dorsal portions of the frog tadpoles at each metamorphosis stage were fixed in 10% buffered formalin at$4^{\circ}C$, embedded in paraffin wax, sectioned 4 $\mu$m thickness and stained with periodic acid-Schiff(PAS) and alcian blue (AB) at both pH 2.5 and pH 1.0. The results of observation were as follows: 1. The developments of cutaneous mucous glands of the frog tadpole were begun with appearance of gland cell nest in the dermis at metamorphosis XV stage and significant numerical increases could be seen at metamorphosis XX, XXIII and XXIV stages. 2. This cutaneous mucous gland of the frog tadpole could be divided into two types; A-type glands showed strong positivities to both PAS and AB at pH 2.5 in the gland body cells and to PAS in the gland neck cells, and B-type glands at AB pH 2.5 in the gland body cells. 3. In the A-type mucous glands, the reactivities of the glandular epithelial cells to both PAS and AB stain could be first seen at the metamorphosis XIX stage of frog tadpole. The reactivities of the glandular epithelial cells to both PAS and AB pH 2.5 were gradually increased according to the process of metamorphosis after XX stage of metamorphosis. 4. The B-type mucous glands were first seen at the XX stage and the reactivity of the glandular epithelial cells to AB at pH 2.5 was gradually increased according to the process of metamorphosis after XX stage. 5. The A-type and the B-type mucous glands were in the ratio of 99 : 1, 7 : 3 and 5.5 : 4.5 for each of metamorphosis XX, XXI-XXII and XXIII-XXV stages. 6. The remarkable development of the cutaneous mucous glands of the frog tadpoles might be needed to maintain water and electrolyte balances according to the change of way from aquatic life to amphibious.

• Journal of Korean Academy of Dental Administration
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• v.5 no.1
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• pp.31-37
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• 2017

Recently interest in infection control is increasing in hospitalsnfection control has become more important in the overall health care practiceental hospital also requires thorough infection control. There are various kinds of vectormedical clothing. Contaminated clothing of a hospital staff can be a vector of nosocomial infecton. actual case of nosocomial infecton caused by contaminated medical clothing, nursing students were measuring contamination levels of uniforms and pathogenic microorganism wdetected in front of the uniform and pocket. There is also a high risk of exposure to contamination in the dental hospital. We conducted a study to enhance awareness about infection and proper clothing management by comparing before and after contamination of clothing caused by aerosols produced during scaling. Subjects were scaling operators' uniforms in the department of dental hygiene, K University located in Daejeon. Before scaling, the uniform was sterilized by autoclavecaling was performed times in the same place (an average of 60 minutes per person, a total of 180 minutes). ive parts of the uniform (sleeves, chest, belly, thigh, edge of pants) contracted Rodak-plate for 15 seconds. After incubating the contacted Rodak-plate at 37℃ incubator, contamination levels by measuring the number of colonies. As a result, all parts increased number of colonies. ontamination order chestedge of pants thigh belly sleeves. Increase rate of colonies was also high in the order chest edge of pants thigh belly sleeves. This study showed seriousness of clothing contaminationcaused by aerol produced during scalingcontamination of clothing can be a path to nosocomial infecton. According to th study, infection control for clothing as well as dental instruments should be implemented and thorough infection control training needed for dental staff. In further researches, practical infection prevention supplementing clothing management method.

• The Journal of KAIRB
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• v.2 no.1
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• pp.23-31
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• 2020

Purpose: To obtain opinions from Korean Institutional Review Board (IRB) members' self-evaluation on ability to conduct fairness review of clinical trial protocol with presence of conflict of interest and from investigators and IRB members on financial conflict of interest through surveying. Methods: IRB members and researchers in 9 different hospitals were asked to answer survey questions via email. Results: Responders were 115 personnel (IRB Chair/vice 18, medical member 30, non-medical member 28, and researcher 39) from 9 centers. Compared to IRB medical members, IRB chair/vice respondents scored higher with statistically significance on 10 point scale (8.44±1.381 vs. 7.30±1.685, p=0.005) when asked to self-evaluate fairness reviewing a protocol proposed by an investigator from the same department and a protocol from the company that supports the scientific committee of responders. When reviewing a protocol proposed by a hospital director, non-medical members scored statistically significantly higher than medical-members (7.47±1.76 vs. 8.07±2.70, p=0.034). When asked about the limitation of labor fee for principal investigator on phase 3 Human clinical trials of the Investigational new drug, while the responses range was wide, 60% answered that labor cost of principal investigator should be less than 30% of total budget for clinical trials with a budget of 100 million won. 51.3% answered that there is no need to disclose the labor cost of the principal investigator in the consent form. Since every investigator can be influenced unconsciously by conflict of interest, the answer that 'responder agrees that there is need for management' was the most chosen answer (IRB member 61.8%, investigator 64.1%, multiple answers allowed). Conclusion: Considering scores on questions of fairness by IRB members were between 7.23-8.56 on scale of 0 to 10 point when IRB members were asked about reviewing a clinical trial protocol, it cannot be said with absolute certainty that there is no issue regarding fairness in the review process. Therefore, there should be more ways to safeguard fairness for these issues. There is a need that the disclosure amount of honorarium from sponsor should be lower than 100 million Korean won. Considering the results of the survey in which respondents expressed their thoughts, it is likely that more education on the concept of conflict of interest is needed.

• The Journal of KAIRB
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• v.2 no.2
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• pp.37-48
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• 2020

Purpose: The purpose of this study is to assess the operational status and level of understanding among IRB and HRPP staffs at a hospital or a research institute to the HRPP guideline set by the Ministry of Food and Drug Safety (MFDS) and to provide recommendations. Methods: Online survey was distributed among members of Korean Association of IRB (KAIRB) through each IRB office. The result was separated according to topic and descriptive statistics was used for analysis. Result: Survey notification was sent out to 176 institutions and 65 (37.1%) institutions answered the survey by online. Of 65 institutions that answered the survey; 83.1% was hospital, 12.3% was university, 3.1% was medical college, 1.5% was research institution. 23 institutions (25.4%) established independent HRPP offices and 39 institutions (60.0%) did not. 12 institutions (18.5%) had separate IRB and HRPP heads, 21 (32.3%) institutions separated business reporting procedure and person in charge, 12 institutions separated the responsibility of IRB and HRPP among staff, and 45 institutions (69.2%) had audit & non-compliance managers. When asked about the most important basic task for HRPP, 23% answered self-audit. And according to 43.52%, self-audit was also the most by both institutions that operated HRPP and institutions that did not. When basic task performance status was analyzed, on average, the institutions that operated HRPP was 14% higher than institutions that only operated IRB. 9 (13.8%) institutions were evaluated and obtained HRPP accreditation from MFDS and the most common reason for obtaining the accreditation was to be selected as Institution for the education of persons conducting clinical trial (6 institutions). The most common reason for not obtaining HRPP accreditation was because of insufficient staff and limited capacity of the institution (28%). Institutions with and without a plan to be HRPP accredited by MFDS were 20 (37.7%) each. 34 institutions (52.3%) answered HRPP evaluation method and accreditation by MFDS was appropriate while 31 institutions (47.7%) answered otherwise. 36 institutions answered that HRPP evaluation and accreditation by MFDS was credible while 29 institutions (44.5%) answered that HRPP evaluation method and accreditation by MFDS was not credible. Conclusion: 1. MFDS's HRPP accreditation program can facilitate the main objective of HRPP and MFDS's HRPP accreditation program should be encouraged to non-tertiary hospitals by taking small staff size into consideration and issuing accreditation by segregating accreditation. 2. While issuing Institution for the education of persons conducting clinical trial status as a benefit of MFDS's HRPP accreditation program, it can also hinder access to MFDS's HRPP accreditation program. It should also be considered that the non-contact culture during COVID-19 pandemic eliminated time and space limitation for education. 3. For clinical research conducted internally by an institution, internal audit is the most effective and sole method of protecting safety and right of the test subjects and integrity for research in Korea. For this reason, regardless of the size of the institution, an internal audit should be enforced. 4. It is necessary for KAIRB and MFDSto improve HRPP awareness by advocating and educating the concept and necessity of HRPP in clinical research. 5. A new HRPP accreditation system should be setup for all clinical research with human subjects, including Investigational New Drug (IND) application in near future.

• Journal of the Korean Society of Food Culture
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• v.21 no.1
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• pp.86-98
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• 2006

This study was conducted to investigate factors affecting bone density of food and nutrition vegetarian and non-vegetarian university students in Seoul area. Data for food habits, dietary and health-related behaviors were obtained by self administered questionnaires. BQI(bone quality index) of the subjects was measured by an Quantitative Ultrasound (QUS). The results are summarized as follows: The average height, weight, BMI and osteopenia percentage of the vegetarian and non-vegetarian male and female student were 172.61cm, 62.42kg, 20.98 and 24.2%; 175.38cm, 72.52kg, 23.71 and 16.7%; 160.47cm, 55.76kg, 21.66 and 55.9%; 161.77cm, 56.34kg, 21.53 and 37.6%, respectively. The BQI of the subjects were 101.73 and 107.43 in male student group, and 84.15, 89.64 in female student group, respectively. The BQI, Z-score value of bone density was significantly different in female group. Weight and BMI were positively related with BQI in male and female group. BQI was positively affected by nutrition supplement and negatively affected by seafood in vegetarian male student group. In vegetarian female student group, amount of meal was positively related with BQI and meal regularity was negatively related BQI. The result of this study revealed that the desirable food habits, dietary behaviors and health-related lifestyles may have a beneficial effect on bone density. They should have practically and systematically organized nutritional education on optimum body weight, good eating habits, weight bearing exercise and intakes of good quality nutrient for higher bone density level.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.1B
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• pp.51-60
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• 2006

Water quality improvement in mattress/filter system using porous material like slag from industrial activity and zeolite that has been studied for environment improvement and pollution abatement is very useful in polluted stagnant stream channel. Slag is consisted of CaO, $SiO_2$, $Al_2O_3$ and $Fe_2O_3$. Slag with large specific surface area of porosity has been used such as sludge settling and adsorptive materials. Because slag is porous, it can be used for purification filter. As slag is used as filled materials of mattress/filter system and the system has good advantages for the waste water treatment, water recycling, and the improvement of water quality at the same time and so on. Because zeolite has much advantage of cation exchange, adsorption, catalyst and dehydration characteristics, It is used for environment improvement of livestock farms, treatment of artificial sewage and waste water, improvement of drinking water quality, radioactive waste disposal and radioactive material pollution control. In this study, according to verifying effects of water quality improvement of fill materials by porosity that 38.6%, 45.8% and 49.8% respectively in the stagnant stream channel, water quality monitoring of inflow and outflow was conducted on pH, DO, BOD, COD, SS, T-N and T-P. Mattress/filter system was able to accelerate water quality improvement by biofilter as waste water flows through gap of mattress/filter fill materials and by contact catalysis, absorption, catabolism by biofilm. Mattress/filter system used slag and zeolite forms biofilm easily and accelerates adsorption of organic matter. As a result, mattress/filter system increases water self-purification and accelerates water quality improvement available for stream water clean-up.

• Journal of Chest Surgery
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• v.2 no.1
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• pp.85-104
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• 1969

This experiment was carried out to study the effect of rapid hemorrhage on cardiopulmonary hemodynamics of the cooled dogs. Hypothermia was induced by means of body surface cooling with ice water. Lowest esophageal temperatures ranged from 24 to 26 degree. Dogs were bled via the femoral artery into a reservoir in amount of the equivalent blood volume of 3% of body weight of the dogs. Some dogs were reinfused with the same amount of blood which they lost and others infused with 5% dextrose solution. Fourty adult mongrel dogs were divided into three groups: group I[15 dogs]; dogs were bled in normothermic state. Five dogs had no further treatment, but five dogs were reinfused with blood and five infused with 5% dextrose solution 30 minutes after bleeding. GroupII[10 dogs]; dogs were bled as group I after having been cooled. Five dogs were reinfused with blood as group I. Group III[15 dogs]; dogs were first bled and then cooled. Reinfusion procedures were the same as in group l Results were as follow: 1. The heart rate showed a slight decrease after bleeding in group I and then increased over the control level after 60 minutes. After reinfusion and infusion, the heart rate was also increased gradually and after three hours almost returned to the control level. In group II and groupIll, the heart rate decreased remarkably and after reinfusion showed a light increase but after infusion tended to decrease cotinually. 2. The stroke volume showed remarkable decrease after bleeding in group I., and recovered to control level after reinfusion and infusion,and then gradually decreased again. In group III, the stroke volume showed no remarkable change after hypothermia, and tended to decrease after reinfusion. In group III, the stroke volume decreased remarkably after bleeding and hypothermia,and clearly increased after reinfusion and infusion and then returned to control level. 3. Femoral mean pressure declined very rapidly and significantly right after bleeding and showed a remarkable prompt rise after reinfusion and infusion in group I [67% recovery]. On the other hand, it declined remarkably after hypothermia and bleeding and showed a slight rise after reinfusion and infusion in group II[46% recovery] and III [41% recovery]. 4. Venous pressure declined slightly after bleeding and tended to return to the control level after reinfusion and infusion,in group I. In group II, it did not change significantly during hypothermia but showed a slight decline after bleeding and returned toward control level after reinfusion. In group III, it declined slightly after bleeding and showed no significant change after hypothermia and rose over the control level after reinfusion and infusion. 5. Right ventricular systolic pressure decreased markedly after bleeding and then increased progressively after 30 minutes. It increased after reinfusion and infusion as well, approaching the control level in group I. In group II, it showed no significant change during hypothermia, but decreased remarkably after bleeding and then returned to near control level after reinfusion. In group III, it was decreased markedly after bleeding but did not change significantly during hypothermia and showed a slight increase after reinfusion. 6. The respiratory rate increased gradually after bleeding and decreased gradually after reinfusion but did not return to the control level, whereas it decreased near to the control level after infusion,and tended to increase in group I. In group II, it decreased significantly after hypothermia and bleeding but returned near to the control level after reinfusion. In group III, it showed a remarkable decrease after hypothermia and increased slightly after reinfusion and infusion but did not returned to the control level. In group I, the tidal volume decreased slightly after hemorrhage, and increased gradually to near the control level after 3 hours following reinfusion.