• Education of Primary School Mathematics
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• v.21 no.1
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• pp.55-73
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• 2018

The purpose of this study is to investigate the effects of cognitive activity on cognitive activities that students imagine and cope with continuously changing quantitative changes in functional tasks represented by linguistic expressions, table of value, and geometric patterns, We identified covariational reasoning levels and investigated the characteristics of students' reasoning process according to the levels of covariational reasoning in the elementary quantitative problem situations. Participants were seven 4th grade elementary students using the questionnaires. The selected students were given study materials. We observed the students' activity sheets and conducted in-depth interviews. As a result of the study, the students' covariational reasoning level for two quantities that are continuously covaried was found to be five, and different reasoning process was shown in quantitative problem situations according to students' covariational reasoning levels. In particular, students with low covariational level had difficulty in grasping the two variables and solved the problem mainly by using the table of value, while the students with the level of chunky and smooth continuous covariation were different from those who considered the flow of time variables. Based on the results of the study, we suggested that various problems related with continuous covariation should be provided and the meanings of the tasks should be analyzed by the teachers.

• Information Systems Review
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• v.4 no.2
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• pp.209-222
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• 2002

EDI (Electronic Data Interchange) has been widely utilized to support Business Activities since it has such advantages as fast transfer of information, less documentation work, efficient information exchange etc. Recently e-business environment has urged the traditional EDI system to be changed to ebXML framework. To apply the ebXML framework to a certain industry, it is required to implement Business Process (BP), Core Component (CC), Collaboration Protocol Profile (CPP), Collaboration Protocol Agreement (CPA), Messaging system etc. We have selected the port and logistics industry as a target domain to apply ebXML framework, since the EDI usage ratio of it is relatively higher than other industries. In this paper, we have analyzed the current status of EDI system and transaction processes in the port and logistics industry. We have defined the business process that will be registered in the registry/repository, the main component of ebXML framework, using UN/CEFACT modeling methodology. And Business Collaborations, Business Transactions, Business Document Flows, Choreography, Pattern, etc. are represented using UML according to UN/ CEFACT modeling methodology, to apply ebXML Framework to the port and logistics distribution industry. Also we have suggested the meta methodology for applying the ebXML framework to other industries.

• Journal of Environmental Impact Assessment
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• v.27 no.3
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• pp.251-266
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• 2018

This study predicted the effect of operation pattern of flood control dam on water quality. Flood control dam temporarily impound floodwaters and then release them under control to the river below the dam preventing the river ecosystem from the extreme flood. The Hydrological Simulation Program Fortran (HSPF) and the Environmental Fluid Dynamics Code (EFDC) were adapted to predict the water quality before and after the dam construction in the proposed reservoir. The non-point pollutant delivery load from the river basin was estimated using the HSPF, and the EFDC was used to predict the water quality using the provided watershed boundary conditions from the HSPF. As a result of water quality simulation, it is predicted that the water quality will be improved due to the decrease of pollution source due to submergence after dam construction and temporary storage during rainfall. There would be no major water quality issues such as the eutrophication in the reservoir since the dam would impound the floodwater for a short time (2~3 days). In the environmental impact assessment stage of a planned dam, there may be some limitations to the exact simulation because the model can not be sufficiently calibrated. However, if the reliability of the model is improved through the acquisition of actual data in the future, it will be possible to examine the influence of the water environment according to various operating conditions in the environmental impact assessment of the new flood control dam.

• Korean Journal of Food Science and Technology
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• v.19 no.6
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• pp.499-505
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• 1987

The functional properties of lupin seed protein concentrate (LPC) were examined and compared to those of soybean protein isolate (SPI) and Na-caseinate. LPC-50, of which protein level was 50%, was prepared by a two phase solvent (hexane: alcohol: water= 10:7:3) extraction method. LPC-70 was made from LPC-50 by removing the fractions solubilized by carbohydrate decomposing enzymes. The solubilities of LPC-50 and LPC-70 were similar to that of of SPI but slightly higher at pH 4-5, and less susceptible to the added salt. The apparent viscosity of LPC increased exponentially as the concentration increased over 6% level, and the change was similar to that of Na-caseinate. LPC showed strong pseudoplastic non-Newtonean flow behavior, which was similar to that of SPI The emulsifying capasity of LPC-70 was similar to that of SPI when salt was added. The foaming capacity of LPC was comparable to that of SPI. LPC showed high oil and water absorption capacities, which increased as the protein level was elevated. LPC-70 showed the highest oil absorption capacity of all the samples tested.

• Proceedings of the Materials Research Society of Korea Conference
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• 2012.05a
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• pp.52-52
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• 2012

최근 선진국을 중심으로 제조기술의 산업혁명이라고 불릴 정도로 큰 파급효과가 기대되는 자기조립기반의 산업공정기술을 확보하기 위한 많은 노력과 연구들이 활발하게 진행되고 있다. 자기조립(Self-Assembly) 현상은 자연에서 일어나는 자발적인 힘으로 원자 또는 분자 단위까지 구조물을 제어하고 bottom-up 방식(상향식: 원자/분자 스케일의 나노구조를 배열/조립하여 원하는 형태의 패턴을 만들어 내는 방식)으로 원하는 구조물을 설계/제작할 수 있는 능력을 가지고 있다. 기초적인 과학으로부터 출발한 자기조립기술은 최근 자기조립 응용개발에서 많은 성과를 이루어내면서 산업화 가능성을 크게 하고, 과학계와 산업계의 많은 관심을 불러일으키고 있다. 반도체 산업기술을 예측하는 ITRS 로드맵(2005년)에 의하면 directed self-assembly 방법이 새로운 미래 패터닝 기술로 개발되어 2016년경에 사용되고, 자기조립소재로 제작된 다양한 응용소자들은 새로운 미래소자로 개발될 것으로 예상하고 있다. 이에 맞추어 국내 기업들도 diblock copolymer를 이용한 나노패터닝 기술 확보를 위한 연구를 진행하고 있다. 또한 IBM은 자기조립기술을 반도체공정에 실험적으로 적용하여 자기조립기술이 생산 공정에 부분적으로 적용될 가능성이 크다는 것을 보여주었다. 산업계와 함께 학계의 연구센터에서는 산업화를 위한 자기조립 집적화 공정(Integrated process) 개발을 이루기 위하여 체계적으로 연구를 실시하고 있다. 미국의 Northeastern 대학의 CHN(Center for high-rate Nanomanufacturing) 연구센터는 자기조립 집적화에 용이한 새로운 개념의 소자를 제안하고 이를 집적화하기 위한 다양한 공정을 개발하고 있으며, Wisconsin 대학의 NSEC(Nanosacle Science and Engineering Center) 연구센터는 diblock copolymer를 이용한 나노패터닝 기술 개발에서 획기적인 결과를 도출하여 산업계에 적용될 가능성을 높이고 있다. 이와 같은 결과들로부터 앞으로의 자기조립기술에 대한 연구는 3차원 구조물을 제작할 수 있는 집적화 공정에 집중될 것이고, 이를 위하여 새로운 개념의 단순한 구조의 응용소자개발도 함께 추진될 것으로 판단된다. 또한 실용 가능성이 큰 집적화 공정으로 개발하기 위하여 기존의 top-down 방식을 접목한 bottom-up 방식의 자기조립 집적화 공정이 개발될 것으로 예상하고 있다. 이와 함께 자기조립공정은 반복되는 구조를 쉽게 제작할 수 있는 장점을 가지고 있어 다양한 응용소자 [태양전지(solar cell), 연료전지(fuel cell), 유연성 있는 전자기기(flexible electronics), 화면표시 장치(display device)] 제작에 쉽게 이용되어 새로운 산업을 창출할 수 있는 가능성을 보이고 있다. 본 자기조립 연구 센터에서는 이와 같은 자기조립 특성을 제조공정에 적용하여 혁신적인 제조공정기술을 확보하고자 연구를 진행하고 있다. 그러므로 본 발표에서 이와 같은 연구 흐름과 함께 본 센터에서 진행하고 있는 자기조립 제조방법을 소개하고자 한다. 이와 함께 자기조립방법을 이용하여 제작된 다양한 응용소자 개발 결과를 발표하고, 이를 top-down 방식과 접목하여 집적화공정으로 개발하는 전략을 함께 소개하고자 한다.

• Journal of Digital Convergence
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• v.10 no.11
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• pp.427-432
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• 2012

The article herein suggested a compound repository and a descriptive method to develop a compound knowledge process. A data target saved in a compound knowledge repository suggested in this article includes all compound knowledge meta data and digital resources, which can be divided into the three following factors according to the purpose: user roles, functional elements, and service ranges. The three factors are basic components to describe abstract models of repository. In this article, meta data of compound knowledge are defined by being classified into the two factors. A component stands for the property about a main agent, activity unit or resource that use and create knowledge, and a context presents the context in which knowledge object are included. An agent of the compound knowledge process performs classification, registration, and pattern information management of composite knowledge, and serves as data flow and processing between compound knowledge repository and user. The agent of the compound knowledge process consists of the following functions: warning to inform data search and extraction, data collection and output for data exchange in an distributed environment, storage and registration for data, request and transmission to call for physical material wanted after search of meta data. In this article, the construction of a compound knowledge repository for recommendation system to be developed can serve a role to enhance learning productivity through real-time visualization of timely knowledge by presenting well-put various contents to users in the field of industry to occur work and learning at the same time.

• Journal of Korean Tunnelling and Underground Space Association
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• v.15 no.5
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• pp.537-546
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• 2013

Traffic congestion in existing tunnels has increased due to increased traffic volume and enlarged vehicles. Enlarging existing tunnels has advantages over constructing new tunnels by reducing land purchasing costs as well as minimizing natural environment destruction. In fact, many overseas projects for enlarging existing tunnels have been reported. Thus, it appears that the demand on enlarging existing tunnels continues to rise in Korea in near future. Nonetheless, the studies related to the enlarged tunnels have been relatively rare since there have been few tunnel enlargement projects in Korea. In the present study, the tunnel behavior and the stability of rock pillar when enlarging existing parallel tunnels were investigated by performing FE analysis and using existing theory and empirical relationships. Four different enlarging cases, depending on the enlargement types and directions, were examined in the study. According to the results, for the tunnels with the same pillar width after enlarged, the uni-laterally enlarged tunnel indicated 5 to 20% higher crown settlement compared to the bi-laterally enlarged tunnel, and for the tunnel with the narrowest pillar, the highest shotcrete stress was observed. Also, the strength/stress ratio for rock pillar was more than 1.0 for all four enlargement cases, and the Matsuda's method was found to give higher strength/stress ratio by about 50% compared to the Peck's method.

• Korean Journal of Environment and Ecology
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• v.32 no.3
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• pp.274-288
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• 2018

This study investigated the environmental factors and fish assemblage in 42 wetlands between spring and autumn of 2017 to evaluate the fish distribution and deduce the management strategy for improving biodiversity in created wetlands located at the Nakdong River basin. The investigation identified a total of 30 fish species and found that the most of wetlands were dominated by exotic fishes such as Micropterus salmoides and Lepomis macrochirus. Fish species such as Rhinogobius brunneus, Opsariichthys uncirostris amurensis, Zacco platypus were less abundant in the area with high density of Micropterus salmoides (static area) because they preferred the environment with active water flow. The pattern analysis of fish distribution in each wetland using the self-organizing map (SOM) showed a total of 24 variables (14 fish species and 10 environmental variables). The comparison of variables indicated that the distribution of fish species varied according to water depth and plant cover rate and was less affected by water temperature, pH, and dissolved oxygen. The plant cover rate was strongly associated with high fish density and species diversity. However, wetlands with low plant biomass had diversity and density of fish species. The results showed that the microhabitat structure, created by macrophytes, was an important factor in determining the diversity and abundance of fish communities because the different species compositions of macrophytes supported diverse fish species in these habitats. Based on the results of this study, we conclude that macrophytes are the key components of lentic freshwater ecosystem heterogeneity, and the inclusion of diverse plant species in wetland construction or restoration schemes will result in ecologically healthy food webs.

• Journal of Korea Water Resources Association
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• v.48 no.2
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• pp.115-126
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• 2015

In recent years, debris flow disaster has occurred in multiple locations between high and low mountainous areas simultaneously with a flooding disaster in urban areas caused by heavy and torrential rainfall due to the changing global climate and environment. As a result, these disasters frequently lead to large-scale destruction of infrastructures or individual properties and cause psychological harm or human death. In order to mitigate these disasters more effectively, it is necessary to investigate what causes the damage with an integrated model of both disasters at once. The objectives of this study are to analyze the mechanism of debris flow for real basin, to determine the PMP and run-off discharge due to the DAD analysis, and to estimate the influence range of debris flow for fan area according to the scenario. To analyse the characteristics of debris flow at the real basin, the parameters such as the deposition pattern, deposit thickness, approaching velocity, occurrence of sediment volume and travel length are estimated from DAD analysis. As a results, the peak time precipitation is estimated by 135 mm/hr as torrential rainfall and maximum total amount of rainfall is estimated by 544 mm as typhoon related rainfall.

• Korean Journal of Food Science and Technology
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• v.16 no.2
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• pp.228-234
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• 1984

A partial hydrolysis of soybean protein isolate was carried out by using pepsin and trypsin. The degree of hydrolysis was evaluated by chemical analysis, viscometric measurements and gel electrophoresis. The functional properties of the hydrolyzates such as flow behavior, emulsion properties and foaming properties were evaluated. A selective hydrolysis of 11S protein fraction by pepsin was observed from the SDS-PAG electrophoresis. The changes in the molecular weight distribution by different conditions of enzyme hydrolysis were evaluated. The changes in the intrinsic viscosity of the protein hydrolylate by reaction time were highly correlated to the contents of TCA soluble protein and 0.03 M $CaCl_2$ soluble nitrogen. The degree of hydrolysis ($DH_{TCA}$, $DH_{Ca}$) were used to evaluate the effect of enzyme treatment on the functional properties of the hydrolyzate. The apparent viscosity and emulsion capacity and stability of the protein solution decreased as DH increased, while the foaming capacity increased linearly with the increasing DH.