• KIEAE Journal
• /
• 제7권1호
• /
• pp.15-22
• /
• 2007

Indoor air quality(IAQ) problems are not limited to large office buildings that are inadequately operated. In fact, many school buildings have significant potentials of air pollution and indoor air pollutants may be of particular concern because it is estimated that most young students who are physically weak to the pollutants spend about 90% of their time in classrooms. The goal of the study is to provide academic and architectural information on the major factors that influence indoor air quality in the elementary school. In order to gain a better understanding of IAQ problems in schools, a series of measurement studies of indoor air quality were designed and 3 different elementary school buildings located in Chuncheon were selected. The levels of CO, $CO_2$, and total volatile organic compounds(TVOCs) including formaldehyde(HCHO), major concern of this study, were measured in absence of students after class. As the results, it is noticeable that most indoor air pollution comes from sources inside the building, which are, for example, adhesives, upholstery, manufactured wood products, art and scientific supplies. The level of CO was measured similarly to that of outdoors, which means no impact on the indoor air problems since it is lower than the code. Ventilation played an important role in the level of $CO_2$ of which difference was 1.7 times in rough and 230 % of difference in the level was detected among the 3 school buildings. This concludes that indoor air problems might be result of poor building design with inadequate location of corridors within space organization or occupant activity patterns of ventilation.

• Journal of Microbiology and Biotechnology
• /
• 제14권4호
• /
• pp.789-795
• /
• 2004

A promoter-probe shuttle vector pSK1Cat was constructed for the isolation of transcriptional signal sequences from Corynebacterium glutamicum. Besides conferring resistance to kanamycin in Escherichia coli and C. glutamicum, the vector carried a promoterless cat gene to confer resistance to chloramphenicol upon insertion of the appropriate transcriptional signals in the multiple cloning site. By utilizing the vector, a series of transcriptionally active fragments were isolated from the genome of C. glutamicum. The clones, ranging from 200 bp to 1 kb in size, were grouped into 3 classes of strong, medium, and weak, based on the chloramphenicol acetyltransferase (CAT) activity and sensitivity to the chloramphenicol of the clone-carrying C. glutamicum cells. C. glutamicum cells carrying the $P_{19}$ clone, a representative in the strong class, were able to grow on minimal agar plates containing over $40 mg/mell$ chloramphenicol, and showed CAT activity of 10 m㏖/mgㆍmin, performing slightly better than the cells carrying $P_{tac}$ , a strong E. coli promoter. Subcloning analysis of the $P_{19}$ clone identified a 180 bp intergenic fragment ($P_{180}$), which was located upstream of a gene encoding a hypothetical membrane protein. The expression conferred by $P_{180}$ was not affected by either the kinds of carbon sources or changes in temperature. These properties make the $P_{180}$ clone useful for the deregulated expression of biosynthetic genes in C. glutamicum during amino acid fermentation.

• 보건교육건강증진학회지
• /
• 제21권2호
• /
• pp.147-165
• /
• 2004

Injury is a leading cause of death in the children and adolescent populations. In particular, more than 80％ of unintentional injury was related to risk-taking behaviors involved in diverse accidents around school and home. Therefore, educational approaches should be provided for children and adolescent populations, and schools are the essential and appropriate sites to conduct safety education. This study was conducted to identify injury prevalence and safety education at schools among middle and high school students in Korea. About 1,034 middle and high students in 28 schools participated in a self-administered survey. The target schools were selected from the stratified random sampling method throughout schools of seven metropolitan cities in Korea. The questionnaires were delivered to the vice-principals by ground mailing service and the vice-principals administered survey data collection. The questionnaire asked about safety education provided in schools, injury experience in the last year, needs for injury prevention class in school, and demographics. All survey responses were entered into SPSS worksheet. Multivariate analysis of variance (MANOVA) and descriptive discriminant analysis (DDA) were used in statistical analysis with SPSS software 11.1. Multivariate analysis of variance was conducted as a preliminary analysis of DDA. According to the result of multivariate analysis of variance, gender (man), grade (poor), living with both parents, and displaying injury prevention messages on school news board were significantly different between the injured student group and the uninjured student group (p＝ .00). These four factors also had significant effects on students' injury experience in DDA, although correlation of the four factors with injury experience was weak overall based on their canonical function coefficients. All structure coefficients of the four factors were greater than .30, which means the four factors have discriminant effects on injury prevalence. The sizes of the discriminant effects, in order, were largly from gender, grade, living with both parents, and safety message display on school news boards.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
• /
• 제1권1호
• /
• pp.35-43
• /
• 1997

Handling the emergency problems such as Chemobyl accident require real time prediction of pollutants dispersion. One-point real time sounding at pollutant source and simple model including turbulent-radiation process are very important to predict dispersion at real time. The stability categories obtained by one-dimensional numerical model (including PBL dynamics and radiative process) are good agreement with observational data (Golder, 1972). Therefore, the meteorological parameters (thermal, moisture and momentum fluxes; sensible and latent heat; Monin-Obukhov length and bulk Richardson number; vertical diffusion coefficient and TKE; mixing height) calculated by this model will be useful to understand the structure of stable boundary layer and to handling the emergency problems such as dangerous gasses accident. Especially, this simple model has strong merit for practical dispersion models which require turbulence process but does not takes long time to real predictions. According to the results of this model, the urban area has stronger vertical dispersion and weaker horizontal dispersion than rural area during daytime in summer season. The maximum stability class of urban area and rural area are 'A' and 'B' at 14 LST, respectively. After 20 LST, both urban and rural area have weak vertical dispersion, but they have strong horizontal dispersion. Generally, the urban area have larger radius of horizontal dispersion than rural area. Considering the resolution and time consuming problems of three dimensional grid model, one-dimensional model with one-point real sounding have strong merit for practical dispersion model.

• 한국의사학회지
• /
• 제25권2호
• /
• pp.11-27
• /
• 2012

King Cheoljong was the twenty-fifth King in the Joseon Dynasty. He did not live a comfortable royal life in his childhood. He succeeded to the crown in the age of 19 after a series of poor days in Ganghwado. During his sovereignty over the territory, the noble class with power interfered with his control in almost every issue, so he could not manage his authority as a ruler. His disease history is hardly included in "Formal Records of the Joseon Dynasty(朝鮮王朝實錄)" which is the prime governmental document, however, some of his disease history appear in "Records of the Diaries of the Kings of Joseon(日省錄)". The primary disease of King Cheoljong was nausea-vomiting, indigestion, diarrhea etc. caused by spleen-stomach weakness. Another main illness was phlegm syndrome. He showed symptoms of coughs, asthma, sputum, and he easily caught cold having a weak health condition. He died at 33 and cause of death was unclear with remaining documents. Just small chances are that the cause was lung tuberculosis. He took a large amount of herbal medicine in his life, which was for curing or toning up his body. Tonifying medicinal herbs were used continuously, and curing herbal medicine was used for spleen-stomach weakness, phlegm syndrome and cold treatment. Treatments of acupuncture and moxa rarely appear in the documents.

• 한국콘텐츠학회논문지
• /
• 제17권5호
• /
• pp.642-657
• /
• 2017

지금으로부터 500년 전에 발생했던 루터의 종교개혁은 교회 안의 부패와 모순, 성경신학적 문제들을 세상에 드러내면서 성경과 초대교회의 가르침으로 돌아가자고 주장했던 "교회 안"만의 개혁이 아니었다. 그로 인해 시작된 종교개혁은 사회 전반적인 모든 분야에 영향을 미쳤고 중세에서 근세로 넘어가는 결정적인 디딤돌이 되었다. 본 연구의 목적은 16세기에 발생했던 루터의 종교개혁 과정에서 분명하게 드러났던 사회복지개혁적 특징이 무엇이었는지를 살펴보고 그것을 현대 기독교적 입장, 특별히 선교적 교회의 관점에서 어떻게 적용할 수 있는지를 제안하는 것이었다. 따라서 본론에서는 이신칭의와 만인사제설 교리가 루터종교개혁의 사상적 토대였음을 확인하였고 신양약자와 여성들과 같이 사회적 약자들에 대한 특별한 관심을 가지면서 현실을 무시하지 않았던 종교개혁이 루터의 종교개혁적 특징임을 살펴보았다. 루터의 사회복지 정책으로는 크게 세 분야로 나누어 볼 수 있는데 가난한 자들을 위한 구호활동, 교육사업, 그리고 경제정책이었다. 그리고 마지막으로 오늘날 현대 기독교가 루터의 사회복지개혁적 특징들을 계승하여 발전시킬 사항으로 현실을 무시하지 않는 사회적 복지실천, 교회의 올바른 실천적인 사회책임 이해, 지역공동체를 위한 실제적 복지실천을 제안하였다.

• 천문학회지
• /
• 제35권3호
• /
• pp.111-121
• /
• 2002

We have measured the correlation functions of the optically selected clusters of galaxies in the Abell and the APM catalogs, and of the X-ray clusters in the X-ray-Brightest Abell-type Clusters of galaxies (XBACs) catalog and the Brightest Clusters Sample (BCS). The same analysis method and the same method of characterizing the resulting correlation functions are applied to all observational samples. We have found that the amplitude of the correlation function of the APM clusters is much higher than what has been previously claimed, in particular for richer subsamples. The correlation length of the APM clusters with the richness R $\ge$ 70 (as defined by the APM team) is found to be $r_0 = 25.4_{-3.0}^{+3.1}\;h^{-1}$ Mpc. The amplitude of correlation function is about 2.4 times higher than that of Croft et al. (1997). The correlation lengths of the Abell clusters with the richness class RC $\ge$ 0 and 1 are measured to be $r_0 = 17.4_{-1.1}^{+1.2}$ and $21.0_{-2.8}^{+2.8}\;h^{-1}$ Mpc, respectively, which is consistent with our results for the APM sample at the similar level of richness. The richness dependence of cluster correlations is found to be $r_0= 0.40d_c + 3.2$ where $d_c$ is the mean intercluster separation. This is identical in slope with the Bahcall & West (1992)'s estimate, but is inconsistent with the weak dependence of Croft et al. (1997). The X-ray bright Abell clusters in the XBACs catalog and the X-ray selected clusters in the BCS catalog show strong clustering. The correlation length of the XBACs clusters with $L_x {\ge}0.65{\times} 10^{44}\;h^{-2}erg\;s^{-1}$ is $30.3_{-6.5}^{+8.2}\;h^{-1}$ Mpc, and that of the BCS clusters with $L_x {\ge}0.70{\times} 10^{44}\;h^{-2}erg\;s^{-1}$ is $30.2_{-8.9}^{+9.8}\;h^{-1}$ Mpc. The clustering strength of the X-ray clusters is much weaker than what is expected from the optical clusters.

• 한국표면공학회지
• /
• 제53권6호
• /
• pp.330-342
• /
• 2020

Since the original report on ferroelectricity in Si-doped HfO2 in 2011, fluorite-structured ferroelectrics have attracted increasing interest due to their scalability, established deposition techniques including atomic layer deposition, and compatibility with the complementary-metal-oxide-semiconductor technology. Especially, the emerging fluorite-structured ferroelectrics are considered promising for the next-generation semiconductor devices such as storage class memories, memory-logic hybrid devices, and neuromorphic computing devices. For achieving the practical semiconductor devices, understanding polarization switching kinetics in fluorite-structured ferroelectrics is an urgent task. To understand the polarization switching kinetics and domain dynamics in this emerging ferroelectric materials, various classical models such as Kolmogorov-Avrami-Ishibashi model, nucleation limited switching model, inhomogeneous field mechanism model, and Du-Chen model have been applied to the fluorite-structured ferroelectrics. However, the polarization switching kinetics of fluorite-structured ferroelectrics are reported to be strongly affected by various nonideal factors such as nanoscale polymorphism, strong effect of defects such as oxygen vacancies and residual impurities, and polycrystallinity with a weak texture. Moreover, some important parameters for polarization switching kinetics and domain dynamics including activation field, domain wall velocity, and switching time distribution have been reported quantitatively different from conventional ferroelectrics such as perovskite-structured ferroelectrics. In this focused review, therefore, the polarization switching kinetics of fluorite-structured ferroelectrics are comprehensively reviewed based on the available literature.

• 한국지반환경공학회 논문집
• /
• 제23권2호
• /
• pp.5-12
• /
• 2022

본 연구는 기존 낙석방지울타리의 시험 방법 중 수직 낙하시험을 중심으로 낙석방지울타리의 성능평가에 대한 시험방법을 제시하기 위해 현장시험을 실시하였다. 국내의 낙석방지울타리 지지 능력을 알아보는 시험은 보통 철망, 지주, 와이어로프를 합친 것으로 시험을 실시하며, 낙석의 충돌위치를 철망의 중앙을 중심으로 실시해 왔다. 하지만 실제 현장에서 낙석이 철망이 아닌 지주에 직접 타격했을 경우, 즉 지주에 직접 타격에 관한 국내 시험적 논문 및 데이터가 전무한 것으로 파악되었다. 따라서 낙석방지울타리(고속도로 형식 2호)를 중심으로 100kJ급의 낙석에너지에 대한 충격을 지주에 타격 했을 시 변위량을 분석하고 기존의 낙석방지울타리 시험과 비교·분석하였다.

• Steel and Composite Structures
• /
• 제43권4호
• /
• pp.447-456
• /
• 2022

Recent experimental studies showed that deep steel I-shaped profiles classified as high ductility class sections in seismic design international codes exhibit low deformation capacity when subjected to cyclic loading. This paper presents an innovative retrofit solution to increase the rotation capacity of beams using bonded carbon fiber reinforced polymers (CFRP) patches validated with advanced finite element analysis. This investigation focuses on the flexural cyclic behaviour of I-shaped hot rolled steel deep section used as beams in moment-resisting frames (MRF) retrofitted with CFRP patches on the web. The main goal of this CFRP reinforcement is to increase the rotation capacity of the member without increasing the overstrength in order to avoid compromising the strong column-weak beam condition in MRF. A finite element model that simulates the cyclic plasticity behavior of the steel and the damage in the adhesive layer is developed. The damage is modelled using the cohesive zone modelling (CZM) technique that is able to capture the crack initiation and propagation. Details on the modelling techniques including the mesh sensitivity near the fracture zone are presented. The effectiveness of the retrofit solution depends strongly on the selection of the appropriate adhesive. Different adhesive types are investigated where the CZM parameters are calibrated from high fidelity fracture mechanics tests that are thoroughly validated in the literature. This includes a rigid adhesive commonly found in the construction industry and two tough adhesives used in the automotive industry. The results revealed that the CFRP patch can increase the rotation capacity of a steel member considerably when using tough adhesives.