• Wind and Structures
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• 제37권2호
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• pp.117-131
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• 2023

Korea Design Standard (KDS) will be updated with two major revisions on the assessment of wind load and performance-based wind design (PBWD). Major changes on the wind load assessment are the wind load factor and basic wind speed. Wind load factor in KDS is reduced from 1.3 to 1, and mean recurrence interval (MRI) for basic wind speed increases from 100 years to 500 years considering the reduction of wind load factor. Additional modification is made including pressure coefficient, torsional moment coefficient and spectrum, and aeroelastic instability. Combined effect of the updates of KDS code on the assessment of wind load is discussed with the case study on the specified sites and building. PBWD is newly added in KDS code to consider the cases with various target performance, vortex-induced vibration, aeroelastic instability, or inelastic behavior. Proposed methods and target performance for PBWD in KDS code are introduced.

• 한국과학교육학회지
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• 제25권2호
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• pp.173-183
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• 2005

본 연구에서는 중등학교 과학 수행평가가 어떤 평가 유형과 채점 방식을 사용하고 있는지 분석하였으며, 이를 토대로 일반화가능도 이론을 이용하여 과학 수행평가 점수가 얼마나 신뢰로운지 분석하였다. 연구 결과, 과학 수행평가의 유형은 크게 지필형과 과제형으로 나눌 수 있었다. 지필형으로는 중등학교 모두 응답제한형 서술형검사만을 실시하고 있었다. 과제형은 과정 평가와 결과물 평가로 나눌 수 있었다. 채점 방식은 1명의 교사가 모든 서술형문항과 수행과제를 채점하거나, 2명의 교사가 수행과제를 나누어 채점하고 있었다. 그러나 2명 이상의 교사가 서술형문항을 나누거나 교차하여 채점하는 경우는 없었다. 표집된 7개 중등학교 과학 수행평가의 신뢰도 분석 결과는 다음과 갇다: (1) 서술형 문항의 특성이 수행과제의 특성보다 학생들의 수행평가 점수에 미치는 영향이 더 큰것으로 나타났다. (2) 수행과제 채점에서 채점자가 피험자를 다르게 채점하는 정도는 학교에 따라 상당한 차이가 있었다. (3) 7개 중등학교 과학 수행평가의 일반화가능도(신뢰도)는 대부분 적정 수준인 0.80에 미치지 못하는 것으로 나타났으며, 적정 수준의 일반화가능도를 얻기 위해서는 지금보다 더 많은 수의 서술형 문항과 수행과제 그리고 채점자가 필요한 것으로 분석되었다.

• 대한화학회지
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• 제65권1호
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• pp.48-57
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• 2021

본 연구는 국제 학업성취도 평가인 TIMSS 2019 사전검사에서 지필 평가와 컴퓨터 기반 평가로 시행된 과학 평가 문항을 분석하여 검사 매체에 따라 문항 정답률에 영향을 미치는지를 문항 및 학년별로 살펴보았다. 그 결과, 4학년과 8학년 모두 검사 매체에 따른 과학과 문항 정답률 차이가 크지 않았다. 학년별로 살펴보면, 8학년보다는 4학년의 경우 정답률 차이가 상대적으로 크게 나타났다. 문항별로 살펴보면, 선다형 문항보다는 서답형 문항의 경우 정답률 차이가 상대적으로 크게 나타났다. 검사 매체 영향에 대한 과학과 평가 문항 내용을 분석한 결과로는 선다형 문항은 지필 평가와 컴퓨터 기반 평가 문항간의 차이가 거의 없었으나, 서답형 문항은 지필 평가에 비해 서답형 문항의 정답률이 낮아지는 경향을 보였다. 또한, 학년별로는 4학년 학생들이 8학년 학생들보다 서답형 문항에서 정답률이 낮아지는 것으로 나타났다. 본 연구를 토대로, 우리나라 컴퓨터 기반 평가의 개발과 현장 도입과 관련된 시사점을 제공하고 컴퓨터 기반 평가가 학교 평가로 잘 정착하기 위한 교육적 함의를 고찰하고자 한다.

• Environmental Analysis Health and Toxicology
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• 제31권
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• pp.11.1-11.6
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• 2016

Objectives A hazard assessment of di(2-ethylhexyl) phthalate (DEHP), a commonly used workplace chemical, was conducted in order to protect the occupational health of workers. A literature review, consisting of both domestic and international references, examined the chemical management system, working environment, level of exposure, and possible associated risks. This information may be utilized in the future to determine appropriate exposure levels in working environments. Methods Hazard assessment was performed using chemical hazard information obtained from international agencies, such as Organization for Economic Cooperation and Development-generated Screening Information Data Set and International Program on Chemical Safety. Information was obtained from surveys conducted by the Minister of Employment and Labor ("Survey on the work environment") and by the Ministry of Environment ("Survey on the circulation amount of chemicals"). Risk was determined according to exposure in workplaces and chemical hazard. Results In 229 workplaces over the country, 831 tons of DEHP have been used as plasticizers, insecticides, and ink solvent. Calculated 50% lethal dose values ranged from 14.2 to 50 g/kg, as determined via acute toxicity testing in rodents. Chronic carcinogenicity tests revealed cases of lung and liver degeneration, shrinkage of the testes, and liver cancer. The no-observed-adverse-effect level and the lowest-observed-adverse-effect level were determined to be 28.9 g/kg and 146.6 g/kg, respectively. The working environment assessment revealed the maximum exposure level to be $0.990mg/m^3$, as compared to the threshold exposure level of $5mg/m^3$. The relative risk of chronic toxicity and reproductive toxicity were 0.264 and 0.330, respectively, while the risk of carcinogenicity was 1.3, which is higher than the accepted safety value of one. Conclusions DEHP was identified as a carcinogen, and may be dangerous even at concentrations lower than the occupational exposure limit. Therefore, we suggest management of working environments, with exposure levels below $5mg/m^3$ and all workers utilizing local exhaust ventilation and respiratory protection when handling DEHP.

• Toxicological Research
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• 제16권3호
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• pp.187-193
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• 2000

The antidotal, anticonvulsant and neuroprotective effects of physostigmine and procyclidine. the combinational prophylactics for organophosphate poisoning, were evaluated in rats. In comparison with a low protective effect (1.6 fold) of atropine (15 mg/kg) and 2-pralidoxime (30 mg/kg), the traditional antidotes regimen, a marked protection ratio of 7.3 fold was achieved by combinational pretreatment with physostigmine (0.05 mg/kg) and procyclidine (10 mg/kg), which was superior to that (3.5 fold) with pyri-dostigmine (0.1 mg/kg) and atropine (15 mg/kg). Rats exposed to a high dose (10 mg/kg. 2 X $LD_{50}$) of diisopropylfluorophosphate showed severe epileptiform seizures on electroencephalography, resulting in necrotic and apoptotic brain injuries in discrete brain regions under histopathological and TUNEL immuno-histochemical examinations in 24 hr. Such seizures and excitotoxic brain injuries were fully prevented by pretreatment with physostigmine (0.05 mg/kg) and procyclidine (10 mg/kg). in contrast to a negligible effect of pyridostigmine (0.1 mg/kg) and atropine (15 mg/kg). Taken together, it is proposed that the prophylactics composed of physostigmine and procyclidine could be a promising regimen for the prevention of lethality, seizures and brain injuries induced by organophosphate poisoning.

• 환경영향평가
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• 제19권4호
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• pp.381-396
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• 2010

It is essential to consider strategies, spatial planning, and reflection of sustainability for the creation of sound urban spaces. To this end, there is a need for plans that can secure better sustainability through strategic environmental assessment (SEA) of plans. This study examined the literature and available precedent to develop a SEA model for administrative plans for urban development including metropolitan plans, urban master plans and urban management plans. In the course of development of the model, environmental issues associated with the urban plans were analyzed by classifying them into ten categories, including "spatial planning," "conservation planning," "greenbelt systems," "habitats." and etc. according to their rank. Furthermore, those issues were reflected on the development of environmental evaluation indices for the plans. Overall and detailed environmental indices that can be applied to the administrative plans for urban development including metropolitan plans, urban master plans and urban management plans were devised for five stages: (1) Establishment of development goals and strategy, (2) Analysis of current status and characteristics, (3) Conceptualization of spatial structure, (4) Planning for each department, and (5) Execution and management. Sub plans are more detailed and concrete. Criteria based on the evaluation indices, when performing evaluations on plans based on each environmental assessment index in reference to experts and the literature, were used to forecast their effects, i.e. whether they had a positive, negative, or no effect or relationship, or whether their effects was uncertain. Based on the forecasts, this study then presents means to establish more improvable plans. Furthermore, by synthesis of the effects according to each index and integration of the process, plans were analyzed overall. This study reflects the characteristics of the present time period based on issues in the SEA process and techniques in upper level administrative plans being newly established, and presents them according to the stage of each plan. Furthermore, by forecasting the effect of plans by stage, this study presents proposals for improvement, and in this aspect, can be meaningful in promoting plan improvements through SEA.

• 보건행정학회지
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• 제21권1호
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• pp.44-60
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• 2011

Background : Surgical site infection(SSI) is one of the important nosocomial infections with pneumonia, urinary tract infection. SSI increases mortality, morbidity, length of stay, and costs for postoperative patients. The purpose of this study was to estimate length of stay(LOS) and health care costs from SSI using the large observational data. The ultimate objective was to show the effect of prevention of SSI. Method : This study used antibiotic prophylaxis evaluation data and claims data of the HIRA(Health Insurance Review and Assessment Service). The study population included 18,361 patients who underwent gastric surgery, endoscopic cholecystectomy, colon surgery, hysterectomy, cesarean section in nationwide hospitals from August to October 2007. SSI group and non-SSI group were matched according to propensity score resulted from logistic regression. The paired t-test was used to compare the difference of the LOS and health care costs between SSI group and non-SSI group. Results : The 598 cases of SSI were detected of total subjects, and the crude SSI rate was 3.3%. For each surgery, SSI rates were 5.5% for gastric surgery, 4.7% for cholecystectomy, 6.6% for colon surgery, 2.6% for hysterectomy, and 1.6% for cesarean section. The 596 cases of SSI and the 596 cases of non-SSI were matched by propensity score. The LOS of SSI group was longer than that of non-SSI group, and the difference was statistically significant. Health care costs of SSI group was more than that of non-SSI group which was significant. Conclusions : SSI increased apparently the LOS and healthcare costs. The economic loss might affect the cost of national healthcare as well as patients and hospitals. This study provided the evidence that the healthcare expenditure could be reduced by preventing SSI.

• 환경정책연구
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• 제9권3호
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• pp.29-46
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• 2010

소음지도를 활용하여 개발계획의 수립단계에서 환경소음을 사전에 예방하기 위한 방안을 제안하였으며 도시기본계획의 전략환경평가와 도시개발사업의 환경영향평가를 대상으로 하였다. 도시기본계획의 전략환경평가에서는 도시지역의 개발계획내용과 소음지도 제작결과를 상호 비교 검토하여 환경소음의 영향을 고려한 계획의 타당성과 입지의 적정성을 검토하고 도시지역의 소음현황과 개발계획의 시행으로 인한 소음영향을 종합적으로 평가하여 그에 따른 장기적인 저감대책을 수립하는 것을 포함한다. 도시개발사업의 환경영향평가에서는 소음지도를 통한 개발지역 주변의 소음현황 파악, 환경소음의 현황과 개발사업으로 인한 소음영향에 대한 종합적인 평가, 다양한 소음저감방안 적용에 따른 소음지도 제작결과의 비교 검토를 통한 최적의 대책 마련 등을 포함한 소음지도 활용방안을 제안하였다.

• 건설안전기술
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• 통권42호
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• pp.92-111
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• 2007

• 소성∙가공
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• 제15권8호
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• pp.556-561
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• 2006

Most of auto-body members are composed of stamping parts. These parts have the non-uniform thickness and plastic work hardening distribution during the forming process. This paper is concerned with the side impact analysis of the ULSAB-AVC model according to the US-SINCAP in order to compare the crashworthiness between the model with and without considering the forming effect. The forming effect is ca]ciliated by one-step forming analysis for several members. The crashworthiness is investigated by comparing the deformed shape of the cabin room the energy absorption characteristics and the intrusion velocity of a car. The result of the crash analysis demonstrates that the crash mode, the load-carrying capacity and energy absorption can be affected by the forming effect. It is noted that the design of an autobody should be carried out considering the forming effect for accurate assessment of crashworthiness.