• Journal of the Institute of Electronics Engineers of Korea SC
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• v.44 no.3
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• pp.64-69
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• 2007

Motion control of the system is a position control of motor. Motion control of an uncertain robot system is considered as one of the most important and fundamental research directions in the robotics. Some distinguished works using linear control, adaptive control, robust control strategies based on computed torque methodology have been reported. However, it is generally recognized within the control community that these strategies suffer from the following problems : the exact robot dynamics are needed and hard to implement, the adaptive control cannot guarantee the performance during the transient period for adaptation under the variation, the robust control algorithms such as the sliding mode control need information on the bounds of the possible uncertainty and disturbance. And it produces a large control input as well. In this dissertation, a motion control for the unmanned intelligent robot system using disturbance observer is studied. This system is affected with an impact vibration disturbance. This paper describes a stable motion control of the system with the consideration of external disturbance. To obtain the stable motion independently against the external disturbance, the disturbance rejection is strongly required. To address the above issue, this paper presents a Disturbance OBserver(DOB) control algorithm. The validity of the suggested DOB robust control scheme is confirmed by several computer simulation results. And the experiments with a motor system is performed to give the validity of applicability in the industrial field. This results make the easier implementation of the controller possible in the field.

• Journal of the Korean earth science society
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• v.23 no.5
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• pp.397-405
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• 2002

This study investigated science gifted middle school students' philosophical views on scientific knowledge, and the effects of discussing and reading related to the knowledge. Ten eighth-graders in a science gifted class participated in this study. The results can be summarized as follows: 1, At the beginning, the students had one of six positions: (a) relativism (n = 2); (b) falsificationism (n = 2); (c) borderline between relativism and eclecticism (n = 1); (d) borderline between falsificationism and eclecticism (n = 3); (e) borderline among relativism, falsificationism, and eclecticism (n = 1); and (f) borderline inductivism and eclecticism (n = 1). This result indicated that most students had on almost modern philosophical view of scientific knowledge. 2, Some students, who had chosen the item of inductivism in some questions of the instrument at the beginning, maintained their selection despite discussions and readings related to scientific knowledge. The data were examples which indicated the difficulty of changing from a traditional view to a modern view of scientific knowledge.

• Korean Journal of Food Science and Technology
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• v.30 no.6
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• pp.1252-1258
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• 1998

Capillary electrophoresis (CE) with rice proteins was used to discriminate 10 domestic rice cultivars in less than 25 min. Most cultivars were differentiated quickly and easily using P-ACN buffer system. CE of rice prolamins allowed classifying ten varieties of Korean rice into three groups. Peak h was characteristic peak for Dongjinbyeo, Gaehwabyeo and Yongnambyeo which were classified into the group of Dongjinbyeo. Chuchungbyeo, Odaebyeo, Mangeumbyeo and Bonggwangbyeo easily differentiated from the group of Dongjinbyeo by the absence of peak h which were classified into the group of Chuchungbyeo. Peak g typical for Illpumbyeo, Hwaseungbyeo and Hwayoungbyeo accounted for 70% of total peak area. They belong to the group of Illpumbyeo. Some cultivars showed specific peak patterns among ten cultivars, Illpumbyeo was differentiated from others by several peaks between peak c and peak f, and the peak d was apparently detected in Odaebyeo not in others. Other minor differences were also found within each group. The result of the study showed that CE has potential for discrimination of rice cultivars. It also possesses the inherent advantages such as low mass requirements, fast seperations, and quantitative analysis through on-capillary UV detection.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2002.02a
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• pp.592-599
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• 2002

본 연구에서는 수삼의 가공전 선별을 위해 현장에서 편리하게 사용할 수 있는 초음파 전달 속도 계측 자동화 시스템을 개발하여 그 성능을 평가하고자 하였으며 결과를 요약하면 다음과 같다. 1. 개발된 시스템은 제어용 컴퓨터, 시스템 구동 및 탐촉자 이동 장치, 하중 변환장치, 초음파 발생 및 송수신 장치 등으로 구성되었다. 2. 제어 및 계측용 프로그램은 압축력, 측정 대상물의 크기, 초음파 전달 시간을 순차적으로 계측하여 초음파 전달 속도를 계산하는 알고리즘을 개발하였으며, Visual Basic 6.0으로 작성되었다. 모터의 작동, A/D 변환, RS232C 통신 등과 관련된 부분은 각각의 모듈화된 함수로서 구동하고자 하였다. 3. 개발된 시스템의 속도와 거리별 이동 거리별 오차를 측정한 결과 0∼0.04mm 범위를 나타내었다. 이 값은 시스템의 허용오차인 0.17mm 오차보다는 현저히 작은 값이었고 15mm/s와 30mm/s의 이동 속도에서 모두 비슷한 크기의 오차값을 나타내었다. 4. 개발된 시스템의 속도별 반복정밀도 실험 결과 측정위치에서의 반복에 의한 정지 위치 오차는 전 구간에서 0.02mm 이내로 나타났고, 이동 평판의 이동속도가 15mm/s였을 경우에는 이동 회수 30회, 이동 거리 60mm일 때 최대 편차 0.019mm를 나타냈으며 이동속도가 30mm/s일 경우에는 이동 회수 40회, 이동거리 20mm에서 0.02mm의 최대 편차를 나타내었다. 5. 5개의 알루미늄 조각의 크기를 시스템으로 측정한 결과 측정값의 최대 편차는 0.08mm였다. 이 값은 시스템의 허용오차인 0.17mm의 50% 수준으로 시스템은 대상물의 크기 측정에 적당하다고 사료되었다. 6. 절단된 수삼의 초음파 전달속도는 평균 396.4m/s였다.를 축열재로 사용할 경우 재생기를 반으로 나누어서 가열부 쪽에 철선을, 냉각부 쪽에 철망을 삽입한 것이 반대로 삽입한 것보다 재생기 양단의 온도차는 높게 나타났고, 재생기 양단의 압력 차는 낮게 나타났다. 재생기 축열재로서 철망-철선을 사용할 경우 철선-철망 ø1.2-150이 전열 표면적은 작으나 재생기 양단의 온도차가 가장 큰 것으로 나타났으며 재생기 양단의 압력 차는 가장 낮게 나타나 공시 철망- 철선 혼합 축열재중 가장 우수함을 알 수 있다. 4. 철망사이에 철선을 삽입한 축열재의 경우, 철망사이에 삽입한 철선의 직경이 큰 것이 철선의 직경이 작은 것보다 재생기의 양단의 온도차가 높게 나타났고 재생기 양단의 압력차는 작게 나타났다. 그러므로 철망사이에 철선을 삽입한 것 중 성능이 우수한 것은 150-ø2. 0-150으로 나타났다. 5. 실험한 재생기 축열재들 중에서 성능이 우수한 것들을 비교한 결과, 복합 철선 ø1.2-1 50이 가장 성능이 좋은 것으로 나타났다.적외선.열풍 복합건조방법이 높게 나타나 이것은 곡물 표면에 원적외선 방사에의한 복사열이 전달되어 열장해를 받았기 때문으로 판단되며, 금후 더 연구하여 적정 열풍온도 및 방사체 크기를 구명해야 할 것이다.으로 보여진다 따라서 옻나무 유래 F는 포유동물의 생식기능에 중요하게 작용하는 것으로 사료된다.된다.정량 분석한 결과이다. 시편의 조성은 33.6 at% U, 66.4 at% O의 결과를 얻었다. 산화물 핵연료의 표면 관찰 및 정량 분석 시험시 시편 표면을 전도성 물질로 증착시키지 않고, Silver Paint 에 시편을 접착하는 방법으로도 만족한 시험 결과를 얻을 수 있었다.째, 회복기 중에 일어나는 입자들의 유입은 자기폭풍의 지속시간을 연장시키는 경향을 보이며 큰 자기폭풍일수

• Magazine of the Korean Society of Agricultural Engineers
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• v.8 no.1
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• pp.1011-1034
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• 1966

This thesis is the final report which has long been studied by the author to obtain the design basis for various hydrological constructions with the specific system suitable to the natural environmental conditions in Korea. This report is divided into two parts: one is to estimate runoff volume from watersheds and the other to estimate the peak discharge for a single storm. According to the result of observed runoff record from watersheds, it is known that Kajiyama formula is useful instrument in estimating runoff volume from watersheds in this country. But it has been found that this formula shows us 20-30% less than the actual flow. Therefore, when wihed to bring a better result, the watershed characteristics coefficient in this formula, that is, f-value, should be corrected to 0.5-0.8. As for the method to estimate peak discharge from drainage basin, the author proposes to classify it in two ways; one is small size watershed and the other large size watershed. The maximum -flood discharge rate $Q_p$ and time to peak Pt obtained from the observed record on the small size watershed are compared by various methods and formulas which are based upon the modern hydrological knowledge. But it was fou.d that it. was not a satisfied result. Therefore, the author proposes. tocomputate $Q_p$, to present 4.0-5.0% for the total runoff volume ${\Sigma}Q$.${\Sigma}Q$ is computed under the assumption of 30mm 103s in watershed per day and to change the theoritical total flow volume to one hour dura tion total flow rate when design daily storm is given. Time to peak Pt is derived from three parameters which are u,w,k. These are computed by relationship between total runoff volume (ha-m unit)and $Q_p$. (C.M.S. unit). Finally, the author checked out these results obtained from 51 hydrographs and got a satisfied result. Therefore the author suggested the model of design dimensionless unit-hydrograph. And the author believes that this model will be much available at none runoff record river site. In the large size watersheds in Korea when the maximum discharge occurs, the effective rainfall is two consequtive stormy days. So the loss in watershed was assutned as 6Omm/2days,and the author proposed 3-hour-daration hydrograph flow distribution percentage. This distribution percentage will be sure to form the hydrograph coordinate.

• Journal of Korean Port Research
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• v.10 no.2
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• pp.17-29
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• 1996

It is required to consider pricing and non-pricing factors and external economy in order to achieve the objects of physical distribution system in a port. Recently, among the three factors, much attention has been paid to non-pricing factor in the system. Although physical distribution service in a port(PDSP)has been frequently mentioned in documents and literature related to port and shipping studies, few study on it has not been systematically and scientifically made due to the following problems; $\circ$ there are not proper criteria to evaluate level and quality of PDSP and as a result it is difficult to set up a unified standard for doing so. $\circ$ algorithms to evaluate problems with complex and ambiguous attributes and multiple levels in PDSP are not available. This thesis aims to establish a paradigm to evaluate PDSP and to abvance existing decision making methods to deal with complex and ambiguous problems in PDSP. To tackle the first purpose, extensive and thorough literature survey was carried out on general physical distribution service, which is a corner stone to handle PDSp. In addition, through interviews and questionnaire to the expert, it have extracted 82 factors of physical distribution service in a port. They have been classified into 6 groups by KJ method and each group defined by the expert's advice as follows; a. Potentiality b. Exactness c. safety d. Speediness e. Convenience f. Linkage Prior to the service evaluation, many kinds of its attributes must be identified on the basis of rational decision owing to complexity and ambiguity inherent in PDSP. An analytical hierarchy process (AHP) is a method to evaluate them but it is not applicable to PDSP that have property of non-additivity and overlapped attributes. Therefore, probablility measure can not be used to evaluate PDSP but fuzzy measure is required. Hierarchical fuzzy integral method, which is merged AHP with fuzzy measure, is also not effective method to evaluate attributes because it has vary complicated way to calculate fuzzy measure identification coefficient of attributes. A new evaluation algorithm has been introduced to solve problems with multi-attribute and multi-level hierarchy, which is called hierarchy fuzzy process(HFP).Analysis on ambiguous aspects of PDSP under study which is not easy to be defined is prerequisite to evaluate it. HFP is different from algorithm existed in that it clarified the relationship between fuzzy measure and probability measure adopted in AHP and that it directly calculates the family of fuzzy measure from overlapping coefficient and probability measure to treat and evaluate ambiguous and complex aspects of PDSP. A new evaluation algorithm HFP was applied to evaluate level of physical distribution service in the biggest twenty container port in the world. The ranks of the ports are as follows; 1. Rotterdam Port, 2. Hamburg Port, 3. Singapore Port, 4. Seattle Port, 5. Yokohama Port, 6. Long beach Port, 7. Oakland Port, 8. Tokyo Port, 9. Hongkong Port, 10. Kobe Port, 11. Los Angeles Port, 12. New york Port, 13. Antwerp Port, 14. Felixstowe Port, 15. Bremerhaven Port, 16. Le'Havre Port, 17. Kaoshung Port, 18. Killung Port, 19. Bangkok Port, 20. Pusan Port

• Resources Recycling
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• v.8 no.5
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• pp.34-43
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• 1999

An elecmc arc cracking reaclor is developed for the productiol~o f ieusuble fuel gas by the thennal destruction of waste oil. The churaclensucs of product gas and ~esiduesf rom arc crachng of wnste lubr~cat~nogil are sludird. Thc product gas is mainly coruposcd of hydrogen 135-4076), acetylene (13-4076), ethylene 13-476) and olher hgdrocnrbons. The contenr of carbon monomde, one or the main product in a conventional low-temperature Lhennal cracking umt, 1s very slnvll in lhis atc cracking expcnmcnt. Total calocctic wlue of product gas shows 11,000-13.000 kcizlkg, which is hiph cnough to use as a ~ L I I I Cga~ s . and the concentralions oC loxic gases arc well below the rcguliltury emission critena The GCIMS analysis of llquld-phase residues shows that the high rnalccular welgllt hydrocilrbons in the waste oil arc cracked into the low malecular weight hydrocarbons snd hydroem,. The dehydrogcnntion is found lo be Lhe main cracking rcacuon due lo the high temperalure ~ ~ ~ d ubcyc edle ctric arc. The average parucle size of soot as the solid-phase residue is 10 3 wm, and the conlents of cabon a ~ hdea vy metals are abovc 60% and under 0.01 ppm, respecttrely. Thc utllizvtion or sool, as industl-id1 rcsource seems lo he reasible aIter refimng.

• Korean Journal of Food Science and Technology
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• v.52 no.2
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• pp.177-182
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• 2020

This study evaluated the effect of steam heating, gamma irradiation, and ultraviolet (UV) irradiation on microorganism reduction in order to determine an effective sterilization method for red pepper powder. The effect of each treatment on the reduction of thermoduric bacteria and total aerobic bacteria in red pepper powder were as follows: 10 kGy gamma irradiation, reduction of 4 log and 6 log CFU/g, respectively; 12 mW/㎠ UV irradiation (264 nm UV-C), reduction of less than 1 log CFU/g; steam heating at 120℃ for 40 s, reduction of approximately 2 log CFU/g. High-temperature short-time processing at 110℃ for 30 s reduced the total bacterial count in Gochujang solution from 5.70 log CFU/g to 2.26 log CFU/g; at 121℃, the solution was commercially sterile. Steam heating resulted in 1, 2, and 4 log microbial inactivation in garlic, onion, and pepper powder, respectively. Steam sterilization, which consumers prefer over other methods, may be an effective method for reducing microorganisms in spice powders, including those in red pepper powder.

• Korean Journal of Food Science and Technology
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• v.52 no.2
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• pp.113-118
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• 2020

We investigated the quality characteristics and antioxidant capacities of Korean commercial yogurt. Twenty commercial yogurt samples exhibited a pH of 4.05-4.51, titratable acidity of 0.80-1.45%, viable counts of 6.65-9.39 log CFU/g, and total phenolic content of 0.71-2.92 mg gallic acid equivalent/g dry weight (dw). Lactic acid was the major organic acid detected by HPLC with UV detection, and its content was 5.4 times and 46.5 times higher than that of malic acid and citric acid, respectively. The tested commercial yogurt samples exhibited antioxidant potential (1.62-8.95 mM trolox equivalent/g, dw) measured based on scavenging activities of DPPH and ABTS radicals. The average antioxidant potentials of commercial set yogurt containing fruit syrup were significantly (p<0.05) higher than that of cream and plain yogurt. A positive linear correlation was observed between the total phenolic content and the antioxidant capacities, suggesting that phenolic components are likely to contribute significantly to the antioxidant potential of commercial yogurt.

• Journal of Distribution Science
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• v.14 no.4
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• pp.103-110
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• 2016

Purpose - This study investigates the improvement of rationalization of distribution structure in Korean diamond market. It also explores the international distribution of diamond and how the distribution of Korean diamond market system was improved. This study also for providing the evaluation method in case of purchasing diamond on the consumers. Research Design, Data, and Methodology - The research investigates how international diamond distribution market has been changed since 1933 by De Beers. The international Diamond rough stone has been deregulated in supply and demand by Debeers since July, 2000, therefore, the price maintenance policy of diamond market also has been changed. In the short term, the diamond price in market has been down, whereas, in the long term, the market share of Debeers has affected the high quality of diamond price in world market. Before 1985, both G color and VVS1 clarity were used as the level of percentages in the diamond certificate of authenticity in Korea. But, after 1985, the diamond certificate of authenticity uses Diamond Grading Report. Results - Between the 1970's and 1980's, Debeers had controlled about 80 percentages of international diamond supply market. But, Debeers share in diamond market fell by 60 percentages in 2000's. Debeers supplied 31%(4390 carets) of international diamond supply and 41%(39 billion dollars) in 2003. However, Debeers shares 50% of market shares in the diamond supply market by Alosa in Russia. In Korea, the diamond grading report system has been used since 1985. But, the diamond grading report system has price bubbles and much irrational parts in grading system methods. Conclusions - 4C, the grading system of diamond, is a method for comparing and evaluating diamond objectively. Diamond is graded according to its color, cut, clarity, and carat. The price of diamond is determined based on its each item. Consumers purchase diamond for the purpose of investment and wearing. In terms of investment, it is recommended to purchase diamond with color of D grade, cut with Excellent or Very Good Cut grade, Clarity of FL or IF, and more than 3 carat. As for wearing purpose, it is highly recommended for diamond to have color of F or G grade, cut of Excellent or Very Good Cut, clarity of VS2 or SI1, and more than 1 carat Before 2000, Central Selling Organization(CSO) distributed about 80 percentages rough diamond to world market exclusively by purchase, classification, assessment, and sales. After 2000, Dbeers diamond company looses slowly market shares, while Almosa diamond company etc. in Russia are taking over world market shares more and more. Debeers market shares have been falling over the years, and the international diamond markets are gradually growing by other international diamond companies. But, there is no change in Korean diamond market after 1980's. Korean diamond distribution needs to follow international level of Diamond Grading System. By using different grading systems with different panel members, Korean diamond grading system needs to follow international perfect grading systems to grow diamond markets and maintain within top 10 diamond markets countries.