• Title/Summary/Keyword: Interest Stability

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Development of Numerical Model for Mixed Soil Problems Using Dry Bulk Density and Investigation of Its Numerical Stability (건조체적밀도를 적용한 혼합토사 수치모델의 개발과 수치적 안정성 평가)

  • Cho, Yong-Hwan;Lee, Kwang-Ho
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.33 no.3
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    • pp.110-121
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    • 2021
  • The importance of tidal flats lost due to industrialization has recently received attention, and attention is being paid to the creation of artificial tidal flats and maintenance of natural tidal flats. However, there is still a lack of understanding about the behavioral characteristics of mud, mud, and sand that form tidal flats. Although research on the movement characteristics of mixed soils such as tidal flats has been conducted through field investigations and hydraulic experiments, interest in developing a numerical model based on these results has not yet reached. In this paper, the purpose of this paper is to establish a mixed soil model that can efficiently manage the low quality of the tidal flats. In constructing a model for reproducing the surface movement of mixed soil, the numerical stability of the reproduction and movement of sand and mud constituting the mixed soil in the numerical model should be considered first, so first, the volume of sand and mud constituting the mixed soil A mixed soil model representing the relationship was proposed based on a topographical diagram representing the geometric structure of the mixed soil. In order to consider the dry bulk density of the mixed soil, it was possible to consider the dry bulk density of the mud by introducing the water content of the mud containing water. In addition, it was confirmed that the mud and sand movement calculation according to the slope collapse of the mixed soil was stably performed through the calculation of the slope collapse of the mixed soil through the numerical analysis model to which the proposed mixed soil model was applied.

Exploring Place Identity and Sustainable Residency of Youth Migrating to Local Areas (청년들의 지방이주와 정주지속을 위한 장소정체성 연구)

  • Lee, Chang-Hyun;Park, Ji-Young
    • Journal of the Korean Institute of Landscape Architecture
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    • v.51 no.3
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    • pp.139-152
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    • 2023
  • Recently, there has been an increasing interest in the migration of young people to local areas. These young people are discovering and reinterpreting local resources to open local businesses while generating new value in local activities and businesses. This study was initiated with the recognition that fundamental solutions are needed for these young people to settle and sustain residence in the local area. Edward Relph stated that 'place' is a fundamental attribute that influences human existence in the world and is the source of stability and identity formation for individuals. This is deeply related to the psychology of young people who have migrated to local areas. These young people accept the unfamiliar 'space' as a 'place' to form stability and personal identity. Therefore, this study utilized PhotoVoice methodology to examine the process and key factors of place identity formation among migrant youths. As a result, the study identified factors that enable young people to settle in local areas and sustain residence while recognizing elements the local government should focus on to support and address the influx of young people. The results of this study can serve as a foundation for addressing the declining population in local areas through the formation of a relationship population and spur the inflow of young people to local cities in the future.

A Study on Monitoring Surface Displacement Using SAR Data from Satellite to Aid Underground Construction in Urban Areas (위성 SAR 자료를 활용한 도심지 지하 교통 인프라 건설에 따른 지표 변위 모니터링 적용성 연구)

  • Woo-Seok Kim;Sung-Pil Hwang;Wan-Kyu Yoo;Norikazu Shimizu;Chang-Yong Kim
    • The Journal of Engineering Geology
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    • v.34 no.1
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    • pp.39-49
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    • 2024
  • The construction of underground infrastructure is garnering growing increasing research attention owing to population concentration and infrastructure overcrowding in urban areas. An important associated task is establishing a monitoring system to evaluate stability during infrastructure construction and operation, which relies on developing techniques for ground investigation that can evaluate ground stability, verify design validity, predict risk, facilitate safe operation management, and reduce construction costs. The method proposed here uses satellite imaging in a cost-effective and accurate ground investigation technique that can be applied over a wide area during the construction and operation of infrastructure. In this study, analysis was performed using Synthetic Aperture Radar (SAR) data with the time-series radar interferometric technique to observe surface displacement during the construction of urban underground roads. As a result, it was confirmed that continuous surface displacement was occurring at some locations. In the future, comparing and analyzing on-site measurement data with the points of interest would aid in confirming whether displacement occurs due to tunnel excavation and assist in estimating the extent of excavation impact zones.

Development of Theme-Based Integrated Unit in the Middle School Science and Analysis of it's Effects (중학교 과학수업을 위한 주제중심 통합단원의 개발 및 효과 분석)

  • Park, Soo-Kyong;Kim, Sang-Dal;Ju, Gook-Yong;Nam, Youn-Kyong
    • Journal of the Korean earth science society
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    • v.22 no.5
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    • pp.350-359
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    • 2001
  • The purpose of this study is to develop theme-based integrated science unit by the interdisciplinary approach and to analyze it's effects on the science achievement and the attitude towards science learning. 'Interaction' and 'Stability' were selected as the integrated themes, and the main concept and subconcept in relation to the themes were extracted from the four areas of science, and the learning contents were constructed in the integrated ways. While the main concept have relevance to subconcept in the interaction, the main concept have little relevance to subconcept in the stability. Therefore, the stability was to fit with middle school integrated science theme, but the interaction was not. The theme-based integrated science units developed was implemented in middle school, and the results are follows. First, the science achievement of group of theme-based integrated science teaching is significantly higher than those of group of traditional teaching. Second, the scores of the test of attitude toward science learning of the group of theme-based integrated science teaching is significantly higher than those of group of traditional teaching. Third, the students' perception of theme-based integrated science teaching was positive. The students have participation, interest, motivation in theme-based integrated science teaching, and students have difficulty in learning theme-based integrated science teaching.

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Studies on the Natural Food Colour made from Sambucus oanadiensis (Sambucus canadiensis에 의한 천연식용(天然食用) 색소(色素)의 개발(開發)에 관(關)하여)

  • Park, Kyo Soo
    • Journal of Korean Society of Forest Science
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    • v.40 no.1
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    • pp.75-81
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    • 1978
  • Elder-berries are economical plants and grown commercially in the United States. Most of the crop is sold to processors and made into natural colour, jellies, jam, port wine or elder berry wine, elder berry juice or used to manufacture of pie mixes. Processors are showing increasing interest in cultivation elder berries. In the present study was wish to find the effect of various factors and practical methods on the processing for the true fruit colour made from fresh elder berries juice as the clearing by the treated pectinase, added sugar, vaccum concentration, extraction of anthocyanosid powder and its property with used prospects. In this study obtained results can be summarized as follows. 1. Pectinase is useful and effected to make clear juice from fresh elder berry juice treated on the $34{\sim}45^{\circ}C$. 2. P.V.C. drum is most useful stored without unfading for clearing elderberry juice and its exposed redish dark purple colour. 3. Clearing elderberry juice stored in the stainless steel drum, changed colour from redish dark purple to dark violets during the stored at the room temperature. 4. Added sugar (Brix $48{\sim}53^{\circ}C$) to the fresh elderberry juice is useful and suitable prospects for to make home juice and wine. 5. The elderberry juice of vaccum concentration is change colour from dark purple to black brown colour during the stored at the room temperature. 6. Its possible to make anthocyanosid powder extracted made from fresh elderberry juice 7. Property of anthocyanosid is an follows. 1) The spectrum of elderberries juice is $523{\sim}530m{\mu}$ 2) The colouring stability is less than $pH_4$ 3) The colouring stability by the heating is less than $pH_4$, and then the more than $pH_4$ is changed colour from redish dark purple to dark brown. 4) By the light colouring stability is less than $pH_4$ 5) The colouring most stability in the pH is $pH_3$ 8. In the future, natural colour made from elderberry juice on the useful prospects is suitable used to make natural fruit juice, ice cream, candy, commercial and home wine, gum, and manufacture of jelly jam, pie maxes, ect.

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Flame Diagnosis using Image Processing Technique

  • Kim, Song-Hwan;Lee, Tae-Young;Kim, Myun-Hee;Bae, Joon-Young;Lee, Sang-Ryong
    • International Journal of Precision Engineering and Manufacturing
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    • v.3 no.2
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    • pp.45-51
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    • 2002
  • Recently the interest for the environment is increasing. So the criterion for the evaluation of the burner has changed. For efficient driving problem, if the thermal efficiency is higher and the oxygen in exhaust gas is lower, then burner is evaluated better. For environmental problem. burner must satisfy NOx limit, soot limit and CO limit. Generally the experienced operator judge of the combustion status of the burner by the color of flame. we don't still have any satisfactory solution against it. the relation of the combustion status and the color of the flame hasn't still been established. This paper is the study about the relation of the combustion status and the color of the flame. This paper describes development of real time flame diagnosis technique that evaluate and diagnose combustion state such as consistency of components in exhaust gas, stability of flame in quantitative sense. In this paper, it was proposed on the flame diagnosis technique of burner using image processing algorithm, the parameter extracted from the image of the flame was used as the input variables of the flame diagnostic system. at first, linear regression algorithm and multiple regression algorithm was used to obtain linear multi-nominal expression. Using the constructed inference algorithm, the amount of NOx and CO of the combustion gas was successfully inferred. the combustion control system will be realized sooner or later.

A Study on Issues of Heavy Debtors and Credit Counseling in Japan : Including the Interview of Counselors in the Credit Counseling Service (일본의 다중채무자문제 및 채무자상담에 관한 연구 :채무자상담기관의 상담자 면접조사를 포함하여)

  • Lee, Hyun-Jin
    • Journal of Families and Better Life
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    • v.25 no.2 s.86
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    • pp.155-172
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    • 2007
  • This study is a qualitative analysis aimed at facilitating a plan of social support for heavy debtors. for this purpose, the status of issues related to heavy debtors in Japan is considered, and more is revealed about the status of operation for non-profit organizations and groups of heavy debtor victims as counseling agencies for heavy debtors. In addition, through interviews conducted with the counselors of these organizations, a survey has been made on whether the credit counseling provides particular functions for and increases the satisfaction of debtors. The root of Japan's large number of heavy debtors lay in that country's excessive growth of consumer financing, the increase of its use, the structural problems on the lending system of consumer financing and legal insufficiency, to name of few fundamental problems. The interviews on debtor counseling in private organizations revealed that the debtors being counseled showed a great change, due primarily to group counseling and activities, in such aspects as psychological stability, learning and understanding about heavy debts and willingness to take action for solving their own problems. In addition, regarding the aspects of time and cost, specialty, mutual exchange of experienced persons, psychological care and educational functions, the importance of the debtor counseling group's role has been established. To improve the problems of heavy debtors in Korea, there is a need to promote the importance of debtor counseling increase the interest and support of the administration, create a sense of solidarity among related organizations and promote public education on consumer credit. The support of the consumer credit industry and the development of human resources are also badly needed.

New Generation of Lead Free Paste Development

  • Albrecht Hans Juergen;Trodler K. G.
    • Proceedings of the International Microelectronics And Packaging Society Conference
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    • 2004.09a
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    • pp.233-241
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    • 2004
  • A new alloy definition will be presented concerning increasing demands for the board level reliability of miniaturized interconnections. The damage mechanism for LFBGA components on different board finishes is not quite understood. Further demands from mobile phones are the drop test, characterizing interface performance of different package constructions in relation to decreased pad constructions and therefore interfaces. The paper discusses the characterization of interfaces based on SnPb, SnPbXYZ, SnAgCu and SnAgCuInNd ball materials and SnAgCuInNd as solder paste, the stability after accelerated tests and the description of modified interfaces strictly related to the assembly conditions, dissolution behavior of finishes on board side and the influence of intermetallic formation. The type of intermetallic as well as the quantity of intermetallics are observed, primaliry the hardness, E modules describing the ability of strain/stress compensation. First results of board level reliability are presented after TCT-40/+150. Improvement steps from the ball formulation will be discussed in conjunction to the implementation of lead free materials In order to optimize ball materials for area array devices accelareted aging conditions like TCTs were used to analyze the board level reliability of different ball materials for BGA, LFBGA, CSP, Flip Chip. The paper outlines lead-free ball analysis in comparison to conventional solder balls for BGA and chip size packages. The important points of interest are the description of processability related to existing ball attach procedures, requirements of interconnection properties and the knowledge gained the board level reliability. Both are the primary acceptance criteria for implementation. Knowledge about melting characteristic, surface tension depend on temperature and organic vehicles, wetting behavior, electrical conductivity, thermal conductivity, specific heat, mechanical strength, creep and relaxation properties, interactions to preferred finishes (minor impurities), intermetallic growth, content of IMC, brittleness depend on solved elements/IMC, fatigue resistance, damage mechanism, affinity against oxygen, reduction potential, decontamination efforts, endo-/exothermic reactions, diffusion properties related to finishes or bare materials, isothermal fatigue, thermo-cyclic fatigue, corrosion properties, lifetime prediction based on board level results, compatibility with rework/repair solders, rework temperatures of modified solders (Impurities, change in the melting point or range), compatibility to components and laminates.

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New Generation of Lead Free Solder Spheres 'Landal - Seal'

  • Walter H.;Trodler K. G.
    • Proceedings of the International Microelectronics And Packaging Society Conference
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    • 2004.09a
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    • pp.211-219
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    • 2004
  • A new alloy definition will be presented concerning increasing demands for the board level reliability of miniaturized interconnections. The damage mechanism for LFBGA components on different board finishes is not quite understood. Further demands from mobile phones are the drop test, characterizing interface performance of different package constructions in relation to decreased pad constructions and therefore interfaces. The paper discusses the characterization of interfaces based on SnPb, SnPbXYZ, SnAgCu and SnAgCuInNd ball materials and SnAgCuInNd as solder paste, the stability after accelerated tests and the description of modified interfaces stric시y related to the assembly conditions, dissolution behavior of finishes on board side and the influence of intermetallic formation. The type of intermetallic as well as the quantity of intermetallics are observed, primaliry the hardness, E modules describing the ability of strain/stress compensation. First results of board level reliability are presented after TCT-40/+150. Improvement steps from the ball formulation will be discussed in conjunction to the implementation of lead free materials. In order to optimize ball materials for area array devices accelareted aging conditions like TCTs were used to analyze the board level reliability of different ball materials for BGA, LFBGA, CSP, Flip Chip. The paper outlines lead-free ball analysis in comparison to conventional solder balls for BGA and chip size packages. The important points of interest are the description of processability related to existing ball attach procedures, requirements of interconnection properties and the knowledge gained the board level reliability. Both are the primary acceptance criteria for implementation. Knowledge about melting characteristic, surface tension depend on temperature and organic vehicles, wetting behavior, electrical conductivity, thermal conductivity, specific heat, mechanical strength, creep and relaxation properties, interactions to preferred finishes (minor impurities), intermetallic growth, content of IMC, brittleness depend on solved elements/IMC, fatigue resistance, damage mechanism, affinity against oxygen, reduction potential, decontamination efforts, endo-/exothermic reactions, diffusion properties related to finishes or bare materials, isothermal fatigue, thermo-cyclic fatigue, corrosion properties, lifetime prediction based on board level results, compatibility with rework/repair solders, rework temperatures of modified solders (Impurities, change in the melting point or range), compatibility to components and laminates.

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A Study on Applicability to Dual-Fuel Engine of Low Caloric Gas (저발열량 가스의 혼소엔진 적용에 관한 연구)

  • Park, Cheol-Woong;Lee, Sun-Youp;Kim, Chang-Gi;Won, Sang-Yeon;Lee, Jang-Hee
    • Journal of the Korean Institute of Gas
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    • v.14 no.1
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    • pp.15-20
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    • 2010
  • The interest on the utilization of landfill gases and biogases for energy production has been increasing due to environment concerns and global warming caused by burning fossil fuels, renewable nature of these gases. Using those synthesis gases to generate energy with engine encourages more efficient collection reducing emissions into the atmosphere and generates revenues for the operators. However the lower calorific value of synthesis gases than that of LPG or CNG affects the combustion stability and power output. Thus it becomes necessary to address disadvantages involved by studying synthesis gases in technological perspective. This paper discussed synthesis gas as a fuel for 60kW dual-fuel engine to produce power in an effective way. The methane diluted with $N_2$ was used as a fuel and developed ECU and injector driver facilitated the investigations with diesel fuel.