• Title/Summary/Keyword: Forming Process

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Synthesis of High-purity Silicon Carbide Powder using the Silicon Wafer Sludge (실리콘 기판 슬러지로부터 고순도 탄화규소 분말 합성)

  • Hanjung Kwon;Minhee Kim;Jihwan Yoon
    • Resources Recycling
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    • v.31 no.6
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    • pp.60-65
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    • 2022
  • This study presents the carburization process for recycling sludge, which was formed during silicon wafer machining. The sludge used in the carburization process is a mixture of silicon and silicon carbide (SiC) with iron as an impurity, which originates from the machine. Additionally, the sludge contains cutting oil, a fluid with high viscosity. Therefore, the sludge was dried before carburization to remove organic matter. The dried sludge was washed by acid cleaning to remove the iron impurity and subsequently carburized by heat treatment under vacuum to form the SiC powder. The ratio of silicon to SiC in the sludge was varied depending on the sources and thus carbon content was adjusted by the ratio. With increasing SiC content, the carbon content required for SiC formation increased. It was demonstrated that substoichiometric SiCx (x<1) was easily formed when the carbon content was insufficient. Therefore, excess carbon is required to obtain a pure SiC phase. Moreover, size reduction by high-energy milling had a beneficial effect on the suppression of SiCx, forming the pure SiC phase.

Robust Dynamic Projection Mapping onto Deforming Flexible Moving Surface-like Objects (유연한 동적 변형물체에 대한 견고한 다이내믹 프로젝션맵핑)

  • Kim, Hyo-Jung;Park, Jinho
    • Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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    • v.7 no.6
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    • pp.897-906
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    • 2017
  • Projection Mapping, also known as Spatial Augmented Reality(SAR) has attracted much attention recently and used for many division, which can augment physical objects with projected various virtual replications. However, conventional approaches towards projection mapping have faced some limitations. Target objects' geometric transformation property does not considered, and movements of flexible objects-like paper are hard to handle, such as folding and bending as natural interaction. Also, precise registration and tracking has been a cumbersome process in the past. While there have been many researches on Projection Mapping on static objects, dynamic projection mapping that can keep tracking of a moving flexible target and aligning the projection at interactive level is still a challenge. Therefore, this paper propose a new method using Unity3D and ARToolkit for high-speed robust tracking and dynamic projection mapping onto non-rigid deforming objects rapidly and interactively. The method consists of four stages, forming cubic bezier surface, process of rendering transformation values, multiple marker recognition and tracking, and webcam real time-lapse imaging. Users can fold, curve, bend and twist to make interaction. This method can achieve three high-quality results. First, the system can detect the strong deformation of objects. Second, it reduces the occlusion error which reduces the misalignment between the target object and the projected video. Lastly, the accuracy and the robustness of this method can make result values to be projected exactly onto the target object in real-time with high-speed and precise transformation tracking.

Ball-milling Induced Changes in the Crystallinity of Quartz and Wear of Milling Media (볼 밀링에 의한 석영의 결정도 변화와 밀링 매체의 마모의 영향)

  • Jin Jung Kweon;Hoon Khim;Sung Keun Lee
    • Korean Journal of Mineralogy and Petrology
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    • v.36 no.2
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    • pp.95-106
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    • 2023
  • Quartz (SiO2) is among the major rock-forming minerals in the earth's crust. The atomistic structures of SiO2 may evolve during diverse frictional processes. The reduction of friction of quartz-rock accompanied by its amorphization, hydration, and formation of silica gel provides mineralogical insights into earthquakes and related phenomena. Ball milling, together with rotary shear experiments have been useful to infer the atomic origins of such processes. In this study, optimal experimental conditions for ball milling for amorphization of SiO2 were determined by taking into account various process variables. The crystallinity of SiO2 gradually decreased and became amorphous as the ball milling time increased at a high milling speed. The degree of wear of the milling media and its effect on the amorphization of SiO2 were analyzed using distinct milling materials (zirconia, stainless steel). The amount of ball wear increased with increasing milling time. Furthermore, the worn stainless steel particles from balls tend to interact with amorphized SiO2 to form Si-O-Cr. These results aid in understanding the process of atomistic structural changes caused by ball milling of divserse materials with relatively high hardness, such as SiO2, and understanding various geological friction processes.

Participatory Action Research on Changing of Poor Single Mother Self-help Group (빈곤 한부모여성 자조집단의 변화에 관한 참여실행연구)

  • Kim, Eun-jeong;Kim, Hyun-jin;Oh, Bo-ram
    • Korean Journal of Social Welfare Studies
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    • v.41 no.1
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    • pp.5-37
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    • 2010
  • The purpose of this study is to see the motive, processes and strategies of change in poor single mother self-help group and analyze meaning in the self help group, agencies and themselves by change. As to this discussion, We seek to grope practical ways for self-help group. By using Participatory Action Research, We intended to an alternative plan in collaborating between practitioners and all concerned. Following four-step-process in this methodology, we explored processes of changing and considered social work practical meaning. On results, first, The motive have come from critical minds that motivate them to choose their way subjectively. We concluded that they have a necessity of change as a groping activity within their capability. Second, On process trying to be changed, They have made initiative decisions about how extensive and deep their changes should be, by discussion being themselves. So they have agreed to aim at purposeful activities beyond just emotional support. Third, they suggested and planned meaningful action as a specific strategy for changing and all these were done by local community volunteering and lecturing for supporting single mother. In conclusion, The 'Change' single mother group activity aim at is, based on subjective decision, to change a practice of a social worker into a practice of participant, and to develop social empowerment more improved to control social condition, which is forming their life, by their own choice. Furthermore, It needs to be considered approach to Community for overcome limits of self help group activities. Based on these consequences, We presented social work practical meaning.

Demonstration and Operation of Pilot Plant for Short-circuit Nitrogen Process for Economic Treatment of High Concentration Nitrogen Wastewater (고농도 질소함유폐수의 경제적 처리를 위한 단축질소공정 파일럿플랜트 실증화 및 운영 결과)

  • Lee, Jae Myung;Jeon, Ji-hyeong;Choi, Hong-bok
    • Journal of the Korea Organic Resources Recycling Association
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    • v.28 no.1
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    • pp.53-64
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    • 2020
  • A 2㎥/d combined wastewater treatment pilot plant containing the multi-stage vertical stacking type nitrification reactor was installed and operated for more than 1 year under the operating conditions of the short-circuit nitrogen process (pH 8, DO 1mg/L and Internal return rate 4Q from nitrification to denitrification reactor). For economically the combination treatment of food wastewater and the leachate from a landfill, the optimal combination ratio was operated by adjusting the food wastewater with the minimum oil content to 5-25% of the total throughput. The main treatment efficiency of the three-phase centrifugal separator which was introduced to effectively separate solids and oil from the food wastewater was about 52% of SS from 116,000mg/L to 55,700mg/L, and about 48% of normal hexane (NH) from 53,200mg to 27,800 mg/L. During the operational period, the average removal efficiency in the combined wastewater treatment process of BOD was 99.3%, CODcr 94.2%, CODmn 90%, SS 70.1%, T-N 85.8%, and T-P 99.2%. The average concentrations of BOD, CODcr, T-N, and T-P of the treated water were all satisfied with the discharge quality standard for landfill leachate ("Na" region), and SS was satisfied after applying the membrane process. On-site leachate had a relatively high nitrite nitrogen content in the combined wastewater due to intermittent aeration of the equalization tanks and different monthly discharges. Nevertheless nitrite nitrogen was accumulated, denitrification from nitrite nitrogen was observed rather than denitrification after complete nitrification. The average input of anti-forming chemical during the operation period is about 2L/d, which seems to be economical compared to the input of methanol required to treat the same wastewater.

Case study of Music & Imagery for Woman with Depression (우울한 내담자를 위한 MI(Music & Imagery) 치료사례)

  • Song, In Ryeong
    • Journal of Music and Human Behavior
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    • v.5 no.1
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    • pp.67-90
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    • 2008
  • This case used MI techniques that give an imagery experience to depressed client's mental resource, and that makes in to verbalism. Also those images are supportive level therapy examples that apply to positive variation. MI is simple word of 'Music and Imagery' with one of psychology cure called GIM(Guided Imagery and Music). It makes client can through to the inner world and search, confront, discern and solve with suitable music. Supportive Level MI is only used from safety level music. Introduction of private session can associate specification feeling, subject, word or image. And those images are guide to positive experience. The First session step of MI program is a prelude that makes concrete goal like first interview. The Second step is a transition that can concretely express about client's story. The third step is induction and music listening. And it helps to associate imagery more easily by used tension relaxation. Also it can search and associate about various imagery from the music. The last step is process that process drawing imagery, talking about personal imagery experience in common with therapist that bring the power by expansion the positive experience. Client A case targets rapport forming(empathy, understanding and support), searching positive recourse(child hood, family), client's emotion and positive support. Music must be used simple tone, repetition melody, steady rhythm and organized by harmony music of what therapist and client's preference. The client used defense mechanism and couldn't control emotion by depression in 1 & 2 sessions. But the result was client A could experience about support and understanding after 3 sessions. After session 4 the client had stable, changed to positive emotion from the negative emotion and found her spontaneous. Therefore, at the session 6, the client recognized that she will have step of positive time at the future. About client B, she established rapport forming(empathy, understanding and support) and searching issues and positive recognition(child hood, family), expression and insight(present, future). The music was comfortable, organizational at the session 1 & 2, but after session 3, its development was getting bigger and the main melody changed variation with high and low of tune. Also it used the classic and romantic music. The client avoids bad personal relations to religious relationship. But at the session 1 & 2, client had supportive experience and empathy because of her favorite, supportive music. After session 3, client B recognized and face to face the present issue. But she had avoidance and face to face of ambivalence. The client B had a experience about emotion change according depression and face to face client's issues After session 4. At the session 5 & 6, client tried to have will power of healthy life and fairly attitude, train mental power and solution attitude in the future. On this wise, MI program had actuality and clients' issues solution more than GIM program. MI can solute the issue by client's based issue without approach to unconsciousness like GIM. Especially it can use variety music and listening time is shorter than GIM and structuralize. Also can express client's emotion very well. So it can use corrective and complement MI program to children, adolescent and adult.

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Multilateral Approach to forming Air Logistics Hub on North East Asia Region (동북아 항공물류허브을 구축하기 위한 다자적 접근방안)

  • Hong, Seock-Jin
    • The Korean Journal of Air & Space Law and Policy
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    • v.19 no.2
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    • pp.97-136
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    • 2004
  • The Northeast Asian air cargo market has expanded tremendously as a result of the opening up of the Chinese market. The importance of the Asia-Pacific region in the global air transport has also increased. The exchange of human and material resources, services, and information in Northeast Asia, which is expected to increase in the near future, requires that the airlines operating within this region adopt a more liberalized approach. This paper introduced alternatives which can be applied to the Northeast Asian airlines industry so as to bring about the integration of regional air transport: First, this paper found a need for individual Northeast Asian nations to alter their policies towards the airlines industry. Second, each country should further liberalize their respective domestic air transport. Third, there is a need for freer air service agreements to be signed between the nations of Northeast Asia. Fourth, the strategic alliances between the airlines operating in Northeast Asia should be further strengthened. Fifth, this liberalization process should be carried out in an incremental manner, beginning with more competitive airports and routes, or with less-in-demand routes. Sixth, there is a need for a shuttle system to be put into place between the main airports in China, Korea, and Japan. Seventh, these three nations jointly develop aviation safety and security systems that are in accordance with international standards. Eighth, the liberalization process of the aviation industry should be undertaken in conjunction with other related fields. Ninth, organizations linking together civil aviation organization in the Asia-Pacific area should be formed, as should each government linking together. By doing so, these countries will be able to establish regular venues through which to exchange opinions on the integration and liberalization of the air cargo market so as to induce the gradual liberalization of the actual market. The liberalization of the air transport in Northeast Asia will prove to be a daunting task in the short term. However, if the Chinese airlines continue to exhibit continuous growth and Japanese airlines are able to complete their move towards a low-cost structure, this process could be completed earlier than expected. Over the last twenty five years the air transport has undergone tremendous changes. The most important factor behind these changes has been the increased liberalization of the market. As a result, rates have decreased while demand has increased. This has resulted in turning the air transport industry, which was long perceived as an industry in decline, into a high-growth industry. The only method of increasing regional exchanges in the air transport is to pursue further liberalization. The country which implements this liberalization process at the earliest date may very well emerge as a leading force within the air transport industry.

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Analysis on Social Area of Taegu (대구시의 사회지역분석)

  • Choi, Seok-Joo
    • Journal of the Korean association of regional geographers
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    • v.3 no.2
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    • pp.209-225
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    • 1997
  • Today, rapid progress of urbanization is discovered commonly in many countries, especially in developing countries, which has led to spatial order and development process of city. Historically, Taegu was a walled city and formed mono-nucleus which was restricted by the castle. As the city grew gradually, the castle was removed as a result of diversification in traffic network, change of socio-economic environment, formation of industrial base and functional distribution. According to reconstruction maps of residential patterns, there was distinctive residential segregation among ethnic groups. Koreans in Taegu in 1939, aggregated densely in the southern and western parts of the city. The Japanese were concentrated densely in the northern and eastern parts of Taegu. And the street pattern within residential areas of the Korean people was shaped like a maze type in contrast with Japanese residential areas, which showed grid pattern of streets. This is another general pattern of almost all colonial cities, especially in Asia. Through this process, today it appears that, out of overall residential areas which occupy the highest ratio in urban land use, those for eminent people influence the functional development of urban spatial structure very heavily as a key point in urban residetial structure. Truly, residential segregation can be seen as the spatial manifestation of uneven distribution of such important scarce resources as housing and residential environment. In this study, the characteristics of locational distribution of the eminent people show their socially and economically stabilized standing in Taegu, taking the aforesaid situation as a background of the study. And the process of this study is as follows ; to examine the forming process of residential areas in the city as a theoretical supporting, to put in order on classical interpretation to formation of residential areas, and general type modern residential areas formation, and economic decision factor of land use. Therefore, this study aims to examine growth and development of eminent persons' residential areas and, at the same time, extract locational characteristics through the pattern of eminent persons' location and predict changes in the future.

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A Study on Priority Analysis of Improvements for Success Factors in Steps of Formation Process of Cooperation Network (산학협력 네트워크 형성 과정의 단계별 성공 요인에 대한 실행 개선 요구 분석 연구)

  • Ahn, Jae-Yeong;Lee, Byung-Wook
    • Journal of vocational education research
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    • v.36 no.1
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    • pp.77-103
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    • 2017
  • The purposes of this study are 1) to analyse the importance and performance of the success factors in steps of Formation process Of Cooperation NetWork(FoCNW) of educational institutions and businesses, and 2) to draw the success factors that need improvement. To achieve these purposes a survey research was conducted with a group of 1,098 (professors, teachers and workers in charge of cooperation at universities, technical colleges, vocational high schools and businesses which are equipped with a cooperation system), and 339 questionnaires were analyzed. The major results of the study are as follows. Firstly, while cooperation workers showed high recognition on the importance of success factors in steps of FoCNW, their performance of those factors was relatively low. Secondly, both the recognition of importance and performance of success factors in steps of FoCNW was higher in educational institutions than in businesses. Thirdly, the success factors in need of improvements from both educational institutions and businesses are 'collecting outer information and consulting' and 'publicizing cooperation competency', 'setting cooperative activities (programs) and contents of agreements', 'managing cooperation quality formally', 'drawing plans for sustainable cooperation improvement' and 'diffusing cooperation network'. The success factors in need of improvements from educational institutions are 'perceiving necessity of and forming consensus on cooperation' and 'deciding and supporting the worker in charge of cooperation', and 'participating and sharing of organization members'. The success factors in need of improvements from businesses are 'deciding goals and performance strategies', 'developing mutual understanding and checking possibility of cooperation with potential partners', and 'evaluating cooperation activities and their outcomes and providing feedback' and 'adjusting contents of agreements and deciding whether to maintain cooperation'. Therefore, efforts from each partner to improve those factors and support from related organizations are necessary.

Effects of Pesticides on Soil Microflora -Changes of the Composition of Soil Bacterial Flora- (농약(農藥)이 토양미생물상(土壤微生物相)에 미치는 영향(影響) - 토양세균(土壤細菌)Flora의 구성변화(構成變化)에 대하여 -)

  • Yang, Chang-Sool
    • Korean Journal of Soil Science and Fertilizer
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    • v.18 no.2
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    • pp.221-226
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    • 1985
  • This investigation was undertaken to clarify the effects of consecutive application of insecticide (Hexachlorocyclohexane: HCH, 10 ppm each year) and fungicide (Tetrachloroisophthalonitrile: TPN, 40 ppm each year) on changes of the composition of soil bacterial flora in the experimental plots treated with each pesticide for two years. For these purposes, the isolating of bacterial cells growing on albumin agar plate was carried out with non-treated, HCH-treated and TPN-treated soil. And these isolated strains were grouping in accordance with the first diagnostic table of Cowan & Steel based on the morphological and physiological characteristics of bacterial cells. The mortality rate of bacteria was 30% in control, 44% in HCH and 51% in TPN plot respectively, in the process of obtaining pure culture. This suggests that the application of HCH or TPN enriched the fastidious bacteria in soil. The proportion of Gram-negative strains to the total isolates was 37% in control, 37% in HCH and 75% in TPN plot respectively. This means that the application of TPN enriched Gram-negative strains in soil. And the application of TPN increased the number of Gram-negative, nonspore-forming strains, and meanwhile decreased the number of spore-forming strains. In the results, the application of HCH or TPN changed considerably the composition of soil bacterial flora. And the influences of HCH and TPH on changes of the composition of soil bacterial flora were not equal each to each.

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