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A Study on LRFD Reliability Based Design Criteria of RC Flexural Members (R.C. 휨부재(部材)의 L.R.F.D. 신뢰성(信賴性) 설계기준(設計基準)에 관한 연구(研究))

  • Cho, Hyo Nam
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.1 no.1
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    • pp.21-32
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    • 1981
  • Recent trends in design standards development in some European countries and U.S.A. have encouraged the use of probabilistic limit sate design concepts. Reliability based design criteria such as LSD, LRFD, PBLSD, adopted in those advanced countries have the potentials that they afford for symplifying the design process and placing it on a consistent reliability bases for various construction materials. A reliability based design criteria for RC flexural members are proposed in this study. Lind-Hasofer's invariant second-moment reliability theory is used in the derivation of an algorithmic reliability analysis method as well as an iterative determination of load and resistance factors. In addition, Cornell's Mean First-Order Second Moment Method is employed as a practical tool for the approximate reliability analysis and the derivation of design criteria. Uncertainty measures for flexural resistance and load effects are based on the Ellingwood's approach for the evaluation of uncertainties of loads and resistances. The implied relative safety levels of RC flexural members designed by the strength design provisions of the current standard code were evaluated using the second moment reliability analysis method proposed in this study. And then, resistance and load factors corresponding to the target reliability index(${\beta}=4$) which is considered to be appropriate level of reliability considering our practices are calculated by using the proposed methods. These reliability based factors were compared to those specified by our current ultimate strength design provisions. It was found that the reliability levels of flexural members designed by current code are not appropriate, and the code specified resistance and load factors were considerably different from the reliability based resistance and load factors proposed in this study.

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The Correlations among Trust, Satisfaction, Commitment, and Relation-Continuing Intention for Internet foundation Fashion Shopping Mall (인터넷 창업 패션 쇼핑몰에 대한 이용고객의 신뢰, 만족, 몰입 및 관계지속의도 간의 구조적 인과관계)

  • Jo, Yoon Ah
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.10 no.6
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    • pp.155-165
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    • 2015
  • The objective of this study is to verify the structural correlations among trust, satisfaction, commitment, relation-continuing intention for internet fashion shopping mall. The statistical significance of questionnaire survey data for 360 customers was verified by using SPSS 18.0 and AMOS 18.0 statistical programs with significance levels of the ${\alpha}=0.05$. First of all, Cronbach's ${\alpha}$ was also assessed to verify the reliability of the measuring tool, and the fitness of the model were also verified to investigate the fitness of this research model. Finally, structural equation model analysis was performed to verify the structural correlations among the structural correlations among trust, satisfaction, commitment, relation-continuing intention for internet fashion shopping mall. On the basis of the empirical analysis, the following key results were drawn. First, trust for internet fashion shopping mall has the positively significant effects on satisfaction. Second, trust for internet fashion shopping mall has the positively significant effects on commitment. Third, trust for internet fashion shopping mall has the positively significant effects on relation-continuing intention. Fourth, satisfaction for internet fashion shopping mall has the positively significant effects on relation-continuing intention. Fifth, commitment for internet fashion shopping mall has the positively significant effects on relation-continuing intention. Sixth, the path of trust${\rightarrow}$satisfaction${\rightarrow}$relation-continuing intention for internet fashion shopping mall has the significant indirect effects, therefore the mediation effect of satisfaction was significant. Seventh, the path of trust${\rightarrow}$commitment${\rightarrow}$relation-continuing intention for internet fashion shopping mall has the significant indirect effects, therefore the mediation effect of commitment was significant.

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Limitations of National Responsibility and its Application on Marine Environmental Pollution beyond Borders -Focused on the Effects of China's Three Gorges Dam on the Marine Environment in the East China Sea- (국경을 넘는 해양환경오염에 대한 국가책임과 적용의 한계 -중국의 산샤댐 건설로 인한 동중국해 해양환경 영향을 중심으로-)

  • Yang, Hee Cheol
    • Ocean and Polar Research
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    • v.37 no.4
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    • pp.341-356
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    • 2015
  • A nation has a sovereign right to develop and use its natural resources according to its policies with regard to development and the relevant environment. A nation also has an obligation not to harm other countries or damage environments of neighboring countries as consequences of such actions of developments or use of natural resources. However, international precedents induce a nation to take additional actions not to cause more damages from the specific acts causing environmental damages beyond national borders, when such acts have economic and social importance. That is to say that there is a tendency to resolve such issues in a way to promote the balance between the mutual interests by allowing such actions to continue. A solution to China's Three Gorges Dam dilemma based on a soft law approach is more credible than relying on a good faith approach of national responsibilities and international legal proceedings since the construction and operation of the dam falls within the category of exercising national sovereign rights. If a large scale construction project such as the Three Gorges Dam or operation of a nuclear power plant causes or may cause environmental damage beyond the border of a nation engaged in such an undertaking, countries affected by this undertaking should jointly monitor the environmental effects in a spirit of cooperation rather than trying to stop the construction and should seek cooperative solutions of mutual understanding to establish measures to prevent further damages. If China's Three Gorges Dam construction and operation cause or contain the possibility of causing serious damages to marine environment, China cannot set aside its national responsibility to meet international obligations if China is aware of or knows about the damage that has occurred or may occur but fail to prevent, minimize, reverse or eliminate additional chances of such damages, or fails to put in place measures in order to prevent the recurrence of such damages. However, Korea must be able to prove a causal relationship between the relevant actions and resulting damages if it is to raise objections to the construction or request certain damage-prevention actions against crucial adverse effects on the marine environment out of respect for China's right to develop resources and acts of use thereof. Therefore, it is essential to cumulate continuous monitoring and evaluations information pertaining to marine environmental changes and impacts or responses of affected waters as well as acquisition of scientific baseline data with observed changes in such baseline. As China has adopted a somewhat nonchalant attitude toward taking adequate actions to protect against marine pollution risks or adverse effects caused by the construction and operation of China's Three Gorges Dam, there is a need to persuade China to adopt a more active stance and become involved in the monitoring and co-investigation of the Yellow Sea in order to protect the marine environment. Moreover, there is a need to build a regular environmental monitoring system that includes the evaluation of environmental effects beyond borders. The Espoo Convention can serve as a mechanism to ease potential conflicts of national interest in the Northeast Asian waters where political and historical sensitivities are acute. Especially, the recent diplomatic policy advanced by Korea and China can be implemented as an important example of gentle cooperation as the policy tool of choice is based on regional cooperation or cooperation between different regions.

Changes of Protein Profiles in Cheonggukjang during the Fermentation Period (전통 청국장의 발효 기간 동안 변화하는 수용성 단백질 개요)

  • Santos, Ilyn;Sohn, Il-Young;Choi, Hyun-Soo;Park, Sun-Min;Ryu, Sung-Hee;Kwon, Dae-Young;Park, Cheon-Seok;Kim, Jeong-Hwan;Kim, Jong-Sang;Lim, Jin-Kyu
    • Korean Journal of Food Science and Technology
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    • v.39 no.4
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    • pp.438-446
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    • 2007
  • The fermented soybean product, cheonggukjang, is favored by many people, partly due to its bio-functional ingredients. Since the fermentation process of cheonggukjang is mediated by enzymes, including proteases, produced by microbes, analysis of the proteome profile changes in cheonggukjang during fermentation would provide us with valuable information for fermentation optimization, as well as a better understanding of the formation mechanisms of the bio-functional substances. The soluble proteins from cheonggukjang were prepared by a phenol/chloroform extraction method, in order to remove interfering molecules for high resolution 2-D gel analysis. Proteomic analysis of the cheonggukjang different fermentation periods suggested that most of the soluble soy proteins were degraded into smaller forms within 20hr, and many microbial proteins, such as mucilage proteins, dominated the soluble protein fraction. The proteomic profile of cheonggukjang was very different from natto, in terms of the 2-D gel protein profile. Among the separated protein spots on the 2-D gels, 50 proteins from each gel were analyzed by MALDI-TOF MS and PMF for protein identification. Due to database limitations with regard to soy proteins and microbial proteins, identification of the changed proteins during fermentation was restricted to 9 proteins for cheonggukjang and 15 for natto. From de novo sequencing of the proteins by a tandem MS/MS, as well as by database searches using BLASTP, a limited number of proteins were identified with low reliability. However, the 2-D gel analysis of proteins, including protein preparation methods, remains a valuable tool to analyze complex mixtures of proteins entirely. Also, for intensive mass spectrometric analysis, it is also advisable to focus on a few of the interestingly changed proteins in cheonggukjang.

Horticultural Therapy: Job Analysis, Performance Evaluation, and Educational Needs (원예치료사의 직무 및 수행평가와 교육요구 분석)

  • Kim, Soo-Yun;Park, Sin-Ae;Son, Ki-Cheol;Lee, Chan
    • Horticultural Science & Technology
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    • v.32 no.6
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    • pp.887-900
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    • 2014
  • This study was conducted to provide a job analysis for, and assess the job performance of horticultural therapists, as well as examine future educational needs. To this end, a chart developed using the DACUM method was chosen as the appropriate tool for the job analysis of horticultural therapists (Study 1). Based on the chart, a survey using an evaluation form was produced to investigate the current level of job performance and future required level of horticultural therapists (Study 2). A total of 8 duties and 45 tasks were classified to examine job performance, based on analysis of the DACUM Council (Study 1). These duties include A. Decide execution organization for horticultural therapy (HT) program, B. Diagnose and assess clients before starting the HT program, C. Plan HT program, D. Develop HT program, E. Prepare to implement HT program for each session, F. Implement HT program for each session, G. Implement overall assessment for HT program, and H. Develop oneself as a horticultural therapist. Their duties were broken down further into five to eight tasks per duty, totaling 45 tasks. Based on the horticultural therapist job performance sheet developed through this process, an assessment of the current job level of horticultural therapists was performed and future required level were examined (Study 2). The evaluation forms were sent to 779 horticultural therapists with level 1 or 2 certification via email or mail delivery. The analysis of 242 questionnaires (31.1%) revealed that horticultural therapists with level 1 certificates have a significantly higher job performance level for 34 of the 45 tasks. Regarding future required level, 20 out of 45 tasks were assessed as higher for level 1 horticultural therapists than level 2. In addition, a Borich formula was utilized to identify the priority of educational needs for the 45 horticultural therapist tasks. The results revealed the following top three tasks: H1. Receive feedback from the supervisor for the horticultural therapy program; A1. Distribute promotional materials about the horticultural therapy program; and H2. Submit a grant proposal for horticultural therapy program to organizations such as welfare foundations. The results of this study are anticipated to facilitate understanding and improve work conditions for current horticultural therapists or horticultural therapists-in-training. In addition, institutions that train horticultural therapists will be able to use this as basic research to develop a practical training curriculum.

Characterizing Responses of Biological Trait and Functional Diversity of Benthic Macroinvertebrates to Environmental Variables to Develop Aquatic Ecosystem Health Assessment Index (환경변이에 대한 저서성 대형무척추동물의 생물학적 형질과 기능적 다양성 분석: 수생태계 건강성 평가 관점에서)

  • Moon, Mi Young;Ji, Chang Woo;Lee, Dae-Seong;Lee, Da-Yeong;Hwang, Soon-Jin;Noh, Seong-Yu;Kwak, Ihn-Sil;Park, Young-Seuk
    • Korean Journal of Ecology and Environment
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    • v.53 no.1
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    • pp.31-45
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    • 2020
  • The biological indices based on the community structure with species richness and/or abundance are commonly used to assess aquatic ecosystem health. Meanwhile, recently functional traits-based approach is considered in ecosystem health assessment to reflect ecosystem functioning. In this study, we developed a database of biological traits for 136 taxa consisting of major stream insects (Ephemeroptera, Plecoptera, Trichoptera, Coleoptera, and Odonata) collected at Korean streams on the nationwide scale. In addition, we obtained environmental variables in five categories (geography, climate, land use, hydrology and physicochemistry) measured at each sampling site. We evaluated the relationships between community indices based on taxonomic diversity and functional diversity estimated from biological traits. We classified sampling sites based on similarities of their environmental variables and evaluated relations between clusters of sampling sites and diversity indices and biological traits. Our results showed that functional diversity was highly correlated with Shannon diversity index and species richness. The six clusters of sampling sites defined by a hierarchical cluster analysis reflected differences of their environmental variables. Samples in cluster 1 were mostly from high altitude areas, whereas samples in cluster 6 were from lowland areas. Non-metric multidimensional scaling (NMDS) displayed similar patterns with cluster analysis and presented variation of taxonomic diversity and functional diversity. Based on NMDS and community-weighted mean trait value matrix, species in clusters 1-3 displayed the resistance strategy in the life history strategy to the environmental variables whereas species in clusters 4-6 presented the resilience strategy. These results suggest that functional diversity can complement the biological monitoring assessment based on taxonomic diversity and can be used as biological monitoring assessment tool reflecting changes of ecosystem functioning responding to environmental changes.

Population-Based Newborn Hearing Impairment Screening Test Using GJB2 Mutation Analysis

  • Lee, Kyung-Ok;Jeong, Su-Jin;Byun, Ji-Young;Kim, Jeong-Sook;Lee, Hye-Jung;Seong, Hye-Soon;Kim, Kyung-Tae
    • Korean Journal of Clinical Laboratory Science
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    • v.39 no.2
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    • pp.113-121
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    • 2007
  • Hearing loss is a common congenital disorder that is frequently associated with mutations in the Cx26 gene (GJB2). Recently, the mutation analysis of GJB2 has been used in a newborn screening test for the detection of hearing impairment. Population-based studies should be performed before the application of genetic testing for the identification of deaf newborns. In this study, 8 positions of GJB2 mutations-including 35delG, 167delT, 235delC, V27I, V37I, M34T, E114G, and I203T-were analyzed using PCR-direct sequencing in a total of 437 healthy Korean neonates. DNAs from dried blood spots were extracted using a commercial DNA extraction kit. The PCR-amplified products (783 bps) of the GJB2 gene were detected using 2% agarose gel electrophoresis and subjected to direct sequencing. The sequences were compared with those in the GenBank database by using the BLAST program. In this study, 5 GJB2 mutations -including V27I (79G>A), V37I (109G>A), E114G (341A>G), I203T (608T>C), and 235delC- were found. Of the 437 neonate samples, 301 subjects showed GJB2 mutations (68.9%, 301/437). The V27I mutation was found in 271 subjects and was the most frequent (62.0%, 271/437). The E114G, I203T and V37I mutations were shown in 146, 17 and 14 subjects, respectively. The 235delC mutation was found in 1 subject. The E114G mutation was frequently accompanied by the V27I mutation. V27I/E114G (97.2%, 143/147) was the most common double mutation and 3 subjects had the double mutation V27I/I203T. A triple mutation, V27I/E114G/I203T, was found in 1 subject. In conclusion, PCR-direct sequencing is a convenient tool for the rapid detection of GJB2 mutations and this data might provide information for the genetic counseling of the GJB2 gene.

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Modification of WASP5 for Ungauged Watershed Management and Its Application (미계측 유역관리를 위한 WASP5 모형의 개선 및 적용성 검토)

  • Kim, Jin-Ho;Shin, Dong-Suk;Kwun, Soon-Kuk
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.9 no.1
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    • pp.29-36
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    • 2007
  • This study was carried out to develop a water quality simulation model for the evaluation of an ungauged watershed. For this purpose, the WASP5 model was selected and modified. The model consists of three sub-models, LOAD-M, DYN-M, and EUT-M. LOAD-M, an empirical model, estimates runoff loadings using point and non-point source data of villages. The Geum River Estuary watershed was selected to calibrate and verify the Modified-WASP5. The LOAD-M model was established using field data of water quality and quantity at the gauging stations of the watershed and was applied to the ungauged watersheds, taking the watershed properties into consideration. The result of water quality simulation using Modified-WASP5 shows that the observed average BOD data from Gongju and Ganggyeong were 2.6 mg/L and 2.8 mg/L, and the simulated data were 2.5 mg/L and 2.4 mg/L, respectively. Generally, simulation results were in good agreement with the observed data. This study focused on formulating an integrated model for evaluating ungauged watersheds. Even though simulation results varied slightly due to limited availability of data, the model developed in this study would be a useful tool for the assessment and management of ungauged watersheds.

Case Study of Fault Based on Drainage System Analysis in the Namdae Stream, Uljin Area (울진 남대천 유역의 수계분석을 통한 단층 규명 사례 연구)

  • Han, Jong-Gyu;Choi, Sung-Ja
    • Economic and Environmental Geology
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    • v.44 no.5
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    • pp.399-412
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    • 2011
  • A DEM (digital elevation model) is produced using a digital topographic map and is now a commonly used tool in geologic surveys. This study aimed to clarify the relationship between knickpoints and faults in the Namdae stream by analyzing a DEM of the area. The Namdae drainage basin was divided into three subbasins (S1, S2 and S3) and their knickpoints developed for the middle to mid-upper regions were extracted from the DEM. The relative steepness Ks and concavity depending on the incision rate was higher in S1 than in S2 and S3 regions. We assumed that the incision rate caused by active erosion resulted from several faults crossing the basins rather than differences in rock types. There are 77 knickpoints in the Namdae drainage area, including the low-ranking branch, and 24 of thses are on the main river system (S1, S2, S3). Of these 77 knickpoints, 27 (38%) are matched by faults, and from the three basins, 13 (54%) correspond with faults, indicating that the knickpoints are connected closely with the faults. For example the average Ks (relative steepness), was 38.8, but in the overlapping area of the Samdang and Doocheon faults the Ks value was 42.99~43.39. We suggest that the faults resulted in geomorphic deformation such as the high-Ksn knickpoints. There was little evdence of relationship between the knickpoints and rock boundaries, with 54% of the knickpoints distributed on the S1, S2, and S3 subbasins. We concluded that the drainage basin knickpoints are the result of fault movement and are a type of geomorphologic deformation that could be useful for surveying Quaternary faults or fault extension.

Preliminary Study of Oxidized Au skarn Model in the Geodo Mine Area to Mineral Exploration (광물자원탐사를 위한 거도광산지역의 산화형 스카른 금광상모델 예비연구)

  • Kim, Eui-Jun;Park, Maeng-Eon;Sung, Kyul-Youl
    • Economic and Environmental Geology
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    • v.42 no.4
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    • pp.289-300
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    • 2009
  • The Geodo mine area, had been developed for Fe and Cu ores since 1963 and abandoned in recent decades, is located in the central part of the Taebaeksan mineralized district. This area comprises of the Jangsan, Myobong, Pungchon, Hwajeol, Dongjeom, and Dumugol Formations in ascending stratigraphic order. These Formations were intruded by the Cretaceous Eopyeong granitoids that appears to produce the Geodo skarn. Their compositions are relatively oxidized quartz monzodiorite to granodiorite (magnetite series, $Fe_2O_3/FeO=0.3{\sim}1.1$). Mineralizations related skarn deposit occur in the Myobong, Pungchon, and Hwajeol Formations. The proximal skarn is zoned from andraditic garnet ($Ad_{44-95}Gr_{1-53}$) predominant adjacent to the Eopyeong granitoids to diopsidic pyroxene ($Hd_{10-100}Di_{0-89}$) predominant away from the one. The differential proportion of garnet and pyroxene is generated by water/rock ratio and their source, such as magmatic and meteoric water. This is useful tool for assessment the overall oxidation state of the entire skarn system. Gold occurs in proximal red to brownish garnet skarn, and genetically associated with Bi- and Te-bearing minerals. Skarn deposit developed in the Geodo mine area is considered as oxidized Au skarn category, based on chemical composition of the Eopyeong granitoids, zonation of skarn, and gold occurrences. Garnet-rich skarn zone will be the main target for exploration of gold in the study area. However, it is needed to the detailed survey on vertical zonation of this area as well as lateral zonation. The result of this survey would provide an important basis for the exploration of the skarn Au deposit in the Geodo mine area.