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A Study on Initial FMS Design Problem considering Machine Selection, Loading and Layout (기계선택, 작업할당, 기계배치를 고려한 FMS의 초기설계에 대한 연구)

  • Ro, In-Kyu;Lee, Bum-Jin
    • Journal of Korean Institute of Industrial Engineers
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    • v.20 no.4
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    • pp.51-63
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    • 1994
  • Many themes have been studied for FMS problems. But most researches have focused on specific themes; Machine selection, Loading, Routing, Machine layout, etc. So many decision makers who want to introduce FMS to his factory, have many problems, because they do not know either what size of FMS should be introduced or what amount of money should be invested. The objective of this research is to help the decision makers who want to introduce FMS. This research consists of three major part, first, Machine selection, second, Loading, and third, Machine Layout. In the first part of the research, machines are selected with minimum cost satisfying the given demand of each part. In the second part, each operations with its required tools are allocated to those machines. In the third part the locations of each selected machines are determined. And dissimilarity coefficients between each pair of machines are calculated as the measure of distance. With above three steps, we have selected machines, allocated operations to those machines, and the layout configuration of those machines. And for each three steps, Mixed Integer Programming models are formulated. In order to solve the large problems and reduce the computer execution time, three heuristic algorithms are developed for the three mixed integer programming models.

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Studies on Differentiation of Aspergillus nidulans (I) : Characterization of temperature-sensitive mutants defective in differentiation of aspergillus nidulans (Aspergillus nidulans의 분화에 있어 온도 감수성 돌연변이주의 특성)

  • 조남정;강현삼
    • Korean Journal of Microbiology
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    • v.20 no.4
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    • pp.173-182
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    • 1982
  • From FGSC 159 strain of Aspergillus nidulans, temperature sensitive mutants that are defective in growth and differentiation have been isolated by N-methyl-N'-nitroN-nitrosoguanidine (NTG) treatment. The optimum concentration of NTG and incubation time to get the highest mutation frequency was $100{\mu}g$ per ml and 1 hour, respectively. The survival frequency was 1%. Among the isolated mutants, five strains that were affected in early steps of differentiation were selected for further studies and named smK, smY, smB, smF, and smZ. The execution point of each mutant was determined and the growing pattern of each mutant at the restrictive temperature was observed under the microscope. Growth of mutant was arrested near at the execution point. From genetic analysis, each temperature-sensitive mutants was thought to have a single recessive gene. The genes of smK, smY, smB, smF, and smZ are linked to the chromosome VII, IV, VIII, I, and VI, respectively. It can be concluded that the genes controlling the differentiation are widely dispersed in the genome. From the results of mutant, smK, it is considered that a single gene can affect a function (functions) which act(s) at two different steps during differentiation.

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Effects of Power Walking Exercise on Fatigue, Blood Lipids, and Body Composition in Overweight Korean College Students with Taeumin Constitution (빠르게 걷기 운동이 과체중 태음인 대학생의 피로, 혈중지질 및 신체조성에 미치는 효과)

  • Shin, Eun-Ju;Kim, Nam-Cho
    • Korean Journal of Adult Nursing
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    • v.20 no.4
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    • pp.561-572
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    • 2008
  • Purpose: To examine the effects of power walking exercise on fatigue and overweight in college students with Taeumin constitution. Methods: According to results of the constitution diagnosis (QSCC II), 58 students who were identified as Taeumin, whose BMI was over 23 were assigned to one of three groups. The power walking group walked fast at a speed of 7,000 steps per hour using a pedometer, and the walking group walked at a speed of 5,000 steps per hour. There was no treatment with control group. Each group's fatigue level, blood lipids and body composition before and after the experiment were compared and analyzed. Results: Total fatigue and total cholesterol decreased significantly in the power walking group compared to the walking group and the control group. Weight decreased significantly in the power walking group compared to the control group, and percentage of body fat decreased significantly in both the power walking group and the walking group compared to the control group. Conclusion: When power walking exercise was used with overweight Taeumin students, fatigue, blood lipid, weight and percentage of body fat decreased significantly.

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EMG Measurement for Lower Leg of Golf Caddies (골프 진행보조요원의 하지근 피로도)

  • Kim, Soon-Lae;Kwon, Young Gook
    • Korean Journal of Occupational Health Nursing
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    • v.9 no.1
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    • pp.49-55
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    • 2000
  • When standing, walking, or running for extended periods of time, fatigue occurs in the legs. Although there are many ways, to release tense or fatigued leg muscles, in the case that there is insufficient time to relax, an easy way to release leg fatigue is using an inclined step (about 3 minutes). This method was more effective than performing stretching exercises as studied. An experiment was conducted on a golf course in the Kangwon province in Korea. Subjects were chosen randomly and consisted of 5 females and 4 males golf caddies. Their main tasks consisted of pulling golf carts to the bottom of a hill for 8 to 10 hours and sometimes lifting and lowering golf clubs during the duration of one day. EMG was measured after work and after using the previously mentioned inclined Steps for the lower legs using ME3000P. This study investigated the types of inclined Steps which would be most effective and appropriate for golf caddies, whether sex difference had any influence existed between male and female workers. The results showed that a step with a $20^{\circ}$ angle was most effective for males and a step with a $25^{\circ}$ angle was most effective for females. Females showed faster recovery from fatigue than males. However, there were no statistical significance between males and females.

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An Experimental Study on the Emission Characteristics of Smoke from the Marine Four-Stroke Diesel Engines Operated in Constant Speed and Various Load Steps (선박용 4행정 디젤엔진의 정속 부하변동 운전시 매연배출특성에 대한 실험연구)

  • Oh, Sang-Hoon;Kim, Jae-Min;Kim, Hyun-Kyu;Yoo, Bong-Whan
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2006.06a
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    • pp.19-20
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    • 2006
  • The emission of particulate matter from marine diesel engines is already restricted by regional regulations in some countries, and IMO has been preparing the regulation for particulate matter from 53rd MEPC. But confusingly, the gravimetric PM measurement methods and procedures are not established clearly yet. On the other hand, smoke measurement method is set clearly, and it can also indicate PM, though it is not direct gravimetric method. As the preparing step for regulations about PM, we measured the smote density of exhaust emission from the marine four-stroke diesel engines operated in constant speed and various load steps on the test-bed, using the filter-type smoke measuring instrument. As a result, we understood the omission characteristics of smoke from the engines. Additionally, to obtain the objective reliability of our measurement data, we carried out experimental studies about various measuring parameters that could affect the smoke density.

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Nonlinear effects on motions and loads using an iterative time-frequency solver

  • Bruzzone, Dario;Gironi, C.;Grasso, A.
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.3 no.1
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    • pp.20-26
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    • 2011
  • A weakly nonlinear seakeeping methodology for predicting motions and loads is presented in this paper. This methodology assumes linear radiation and diffraction forces, calculated in the frequency domain, and fully nonlinear Froude-Krylov and hydrostatic forces, evaluated in the time domain. The particular approach employed here allows to overcome numerical problems connected to the determination of the impulse response functions. The procedure is divided into three consecutive steps: evaluation of dynamic sinkage and trim in calm water that can significantly influence the final results, a linear seakeeping analysis in the frequency domain and a weakly nonlinear simulation. The first two steps are performed employing a three-dimensional Rankine panel method. Nonlinear Froude-Krylov and hydrostatic forces are computed in the time domain by pressure integration on the actual wetted surface at each time step. Although nonlinear forces are evaluated into the time domain, the equations of motion are solved in the frequency domain iteratively passing from the frequency to the time domain until convergence. The containership S175 is employed as a test case for evaluating the capability of this methodology to correctly predict the nonlinear behavior related to wave induced motions and loads in head seas; numerical results are compared with experimental data provided in literature.

Mathematics across the Curriculum - Educational Reform as a Problem Solving Activity -

  • Cerreto, Frank A.
    • Proceedings of the Korea Society of Mathematical Education Conference
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    • 2007.06a
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    • pp.7-19
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    • 2007
  • During the past 20 years, a small but potentially powerful initiative has established itself in the mathematics education landscape: Mathematics Across the Curriculum (MAC). This curricular reform movement was designed to address a serious problem: Not only are students unable to demonstrate understanding of mathematical ideas and their applications, but also they harbor misconceptions about the meaning and purpose of mathematics. This paper chronicles the brief history of the MaC movement. The sections of the paper correspond loosely tn the typical steps one might take to solve a mathematics problem. The Problem Takes Shape presents a discussion of the social and economic forces that led to the need for increased articulation between mathematics and other fields in the American educational system. Understanding the Problem presents the potential value of exploiting these connections throughout the curriculum and the obstacles such action might encounter. Devising a Plan provides an overview of the support systems provided to early MAC initiatives by government and professional organizations. Implementing the Plan contains a brief description of early collegiate programs, their approaches and their differences. Extending the Solution details the adoption of MAC principles to the K-12 sector and throughout the world. The paper concludes with Retrospective, a brief discussion of lessons learned and possible next steps.

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The Effect of Heat Treatment on Shrinkage and Mechanical Properties of PET Filament (섬유공정에서의 습.건열처리가 PET 필라멘트사의 열수축과 인장특성에 미치는 영향)

  • 김경렬;김승진;김태훈;김영진;이응곤;송재수
    • Textile Coloration and Finishing
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    • v.10 no.3
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    • pp.10-19
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    • 1998
  • This paper investigates the change of mechanical properties and thermal shrinkage in commercial multi-filament PET(polyethylene terephthalate) , namely, regular yarn, POY, DTY and composite yarn. To determine changing the effects of processing steps, these were examined at three steps process simulation conditions. The first step is sizing simulation$(S-1\;step\;:\;130^\circ{C}\times2\;min$., hot air treatment under 0.1 gf/d load), the second step is scouring simulation$(S-2\;step\;:\;100^\circ{C}\times20\;min$., boiling water treatment under free tension)and final step is setting simulation$(S-3\;step\;:\;180^\circ{C}\times2\;min$., hot air treatment under free tension). Regular yarn in multi-step treatment showed higher shrinkage at S-3 step and DTY showed higher in at S-1 step. While POY was relaxed at S-1 step, composite yarn showed different shrinkage properties depending on composite yarn type. Mechanical properties showed good relationship with shrinkage : high shrinkage makes initial modulus decrease and bleating strain increase. It also makes decreasing yield strain and yield stress decrease.

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Synthesis of Silver Nano-particles by the Solution Plasma Sputtering Method (유체 플라즈마 방식을 사용한 은 나노파티클의 합성)

  • Yoo, Seung-cheol;Shin, Hong-Jik;Choi, Won Seok
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.65 no.3
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    • pp.216-218
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    • 2016
  • In this study, we used not chemical and physical synthesis method but the solution plasma sputtering method in the synthesis of silver nano-particles. Synthesis of all the silver nano-particles was conducted for 1hour in 360 ml of distilled water and characteristics of changing the input voltage and frequency of the synthesised silver nano-particles by using the solution plasma sputtering method were analyzed through FE-SEM(Field Emission-Scanning Electron Microscope). We changed the input voltage from 8 kV to 10 kV in steps of 1 kV, input frequency from 20 kHz to 30 kHz in steps of 5 kHz in the solution plasma reactor with the advanced device which can control the DC voltage and frequency. We confirmed that the size of silver nano-particles were larger according to the change of the input voltage and frequency.

Column regeneration for Partisil/Partisphere ion-exchange columns (Partisil/Partisphere 이온 교환 컬럼 재생 가이드)

  • Mark Fever;Gemma Howse
    • FOCUS: LIFE SCIENCE
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    • no.1
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    • pp.5.1-5.3
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    • 2024
  • The document discusses the regeneration of Partisil/Partisphere ion-exchange columns in chromatography. It mentions that column efficiency can diminish with use due to the accumulation of sample and/or mobile phase impurities at the head of the column. This can lead to a change in back pressure, lower column efficiency, and sometimes a change in selectivity. The document outlines a procedure that may restore column performance. The document also provides everyday practices to enhance the lifetime of a column. These include using only high-purity HPLC solvents and buffers, using freshly prepared mobile phases and buffers, filtering mobile phases to remove particulates, using appropriate sample clean-up procedures, using a guard column or pre-column filter, and working within the pressure and flow rate limitations of the column. For the regeneration of Partisil/Partisphere SAX, SCX, WAX, and WCX columns, the document suggests passing 20 column volumes of various mobile phases through the column. These include a buffer wash, distilled water, an acid wash, a chelating wash, a methanol wash, and a buffer for separation. The document emphasizes that not all of these wash steps are required for every column clean-up and that some chromatographers require only a combination of certain steps.

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