• Title/Summary/Keyword: External quality control

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A Study on the Quality Culture of KOREA TELECOM (한국통신의 품질문화에 대한 연구)

  • 한현배
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.17 no.30
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    • pp.117-123
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    • 1994
  • To improve quality of an product We have adopted new approaches such as SPC(Statistical Process Control), CIM(compure Integreated Munufactture), QDF(Quality Development Function), etc. In spite of using these approaches, an organization should fail to achive its true goal if that organization didn't developed its cooperative quality culture which is the total of collective and shared learning of quality-related values as the organization have developed its capacity to survive in its external environment and to manage its own internal affairs. In this paper, I analyzed the current quality culture of Korea Telecom and tried to suggest how Korea Telecom develop its service quality based on the quality culture.

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Nondestructive estimation of external quality of cherry tomato fruits by hydroponics (방울토마토의 수경재배시 외형형질의 비파괴적 추정)

  • 김영식
    • Proceedings of the Korean Society for Bio-Environment Control Conference
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    • 1994.05a
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    • pp.92-95
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    • 1994
  • 과실의 형질을 비파괴적으로 추정하는 방식은 파괴적 추정방식에 비해 연속적으로 측정이 가능하여 생육상태를 상세히 분석할 수 있으며, 같은 과실에 대하여 반복하여 측정할 수 있는 장점을 지닌다는 점에서 생장분석에 유용하게 사용되고 있는 방식이다. 또한 비파괴적 추정은 simulation에 의한 자동화 등에 적용할 수 있어 최적생장조건을 설정하는데 사용되며, 다량의 과실을 자동선별 및 자동수확하는데 이용될 수 있다. (중략)

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Fuzzy Control and Optimization for the Wastewater Treatment Process (퍼지제어기를 이용한 하폐수처리공정의 최적화)

  • 천성표;김봉철;김성신
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2000.11a
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    • pp.452-455
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    • 2000
  • There are increasingly important financial incentives and environmental consideration to improve the effluent quality of wastewater from domestic and industrial users. The activated sludge process is a widely used biological wastewater treatment process. The activated sludge process is complicated due to the many factors such as the variation of influent flowrate and concentration, the complexity of biological reactions and the various operation conditions. Nowadays, not only suspended solids and residual carbon, but also nitrogen and phosphorous concentration of the effluent water must be taken into account for the design and operation of wastewater treatment plants. Also, the effluent quality to be met are more stringent. Therefore, an intelligent control approach is required in order to successful biological nitrogen removal. In this paper, the strategies for dosage of extra carbon in the anoxic zone and DO concentration in the aerobic zone are presented and evaluated through the simulation using the denitrification layout of the IWA simulation benchmark implemented by Matlab$\^$/5.3/Simulink$\^$/3.0. The control strategy to achieve sufficient denitrification rates in an anoxic zone. Methanol is used as an external extra carbon source. The external extra carbon source is required for the nitrogen removal process because nitrogen and organic concentration are fluctuated in the influent flowrate. The dissolved oxygen is calculated by So concentration in the activated sludge model NO.1. The air flowrate of each aerobic reactor is intelligently controlled to achieve the predefined setpoints. Air flowrate is adjusted by the fuzzy logic controller that includes two inputs and one output. The objective function for the optimization procedure is designed to improve effluent quality and reduce the operating cost.

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Non-Destructive Estimation of External Quality of Cherry Tomato Fruits by Hydroponics (방울토마토의 수경재배시 외형형질의 비파괴적 추정)

  • 김영식
    • Journal of Bio-Environment Control
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    • v.3 no.1
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    • pp.52-57
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    • 1994
  • The external qualities of cherry tomato fruits(Lycopersicon esculentum) grown in circulating deep flow hydroponic culture were non - destructively estimated in 1992 under warm climate conditions and evaluated in 1993-1994 under cool season. The fruit size of ‘Minicarol’ was by far the smallest compared to ‘Chelseamini’ and ‘Popo’. There were high correlations between external qualities of fruits-lengthwise growth harmonized with widthwise growth. The volume and/or weight of fruit could be non -destructively estimated by length and width of fruit. Volume=0.071$\times$ (length+width)$^3$+0.451, Fresh weight=0.072$\times$ (length+width)$^3$+0.542. These models were accurately evaluated by fruits harvested in 1994.

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Packaging Standardization for Biological Control Agents (천적 곤충 포장 표준화에 관한 연구)

  • Ham, Eun Hye;Nam, Yun Bok;Jun, Hye Jeong
    • Korean journal of applied entomology
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    • v.60 no.2
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    • pp.203-214
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    • 2021
  • This study aimed at establishing a packaging standardization method that allows the maintenance of biological control agents product quality during delivery. First, based on the results of distribution status analysis of biological control agent products from four manufacturers, we confirmed that the mean temperature was maintained at 25.6℃ (minimum and maximum temperatures.: 18.1 and 30.7℃, respectively) inside the packaging box of each company for 36-48 h. To establish the optimal packaging method for each season, seven external temperature conditions were set ranging between 0℃ and 30℃ at intervals of 5℃. In addition, we evaluated internal temperature maintenance performance for each coolant pack handling method and determined 14 packaging combinations. A packaging combination that maintained a temperature of 3℃ - 9.9℃ at each external temperature conditions was considered efficient. This temperature range is close to a lower developmental threshold at which the biological control agents can survive with minimum energy for 12 h (direct delivery time), or 36-48 h (general delivery time) after packaging.

Effects of a Comprehensive Rehabilitation Program for Mastectomy Patients (유방절제술 환자를 위한 통합적 재활 프로그램의 효과)

  • 조옥희
    • Journal of Korean Academy of Nursing
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    • v.34 no.5
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    • pp.809-819
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    • 2004
  • Purpose: The purpose of this study was to investigate the effect of a comprehensive rehabilitation program on physical function, immune response, fatigue and quality of life in mastectomy patients. Method: The subjects included fifty-five patients with breast cancer (27 in the control group and 28 in the experimental group). The subjects in the experimental group participated in a comprehensive rehabilitation program for10 weeks, which was composed of 1 session of education, 2 sessions of stress management, 2 sessions of exercise, and 1 session of peer support group activity per week. Result: The results revealed anincrease in shoulder extension, abduction, external rotation, and internal rotation of the affectedupper extremity, and in shoulder extension and abduction of the healthy upper extremity. Also an increase in quality of life and a decrease in fatigue were significantly higher in the experimental group than the control group. However, the results revealed that the natural killer cell ratio of the experimental group increased but there was no significant difference from that of the control group. Conclusion: The 10-week comprehensive rehabilitation program showed a large affirmative effect on physical function, fatigue and quality of life of breast cancer patients after a mastectomy.

A Study on the Improvement of Human Operators' Performance in Detection of External Defects in Visual Inspection (품질 검사자의 외관검사 검출력 향상방안에 관한 연구)

  • Han, Sung-Jae;Ham, Dong-Han
    • Journal of the Korea Safety Management & Science
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    • v.21 no.4
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    • pp.67-74
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    • 2019
  • Visual inspection is regarded as one of the critical activities for quality control in a manufacturing company. it is thus important to improve the performance of detecting a defective part or product. There are three probable working modes for visual inspection: fully automatic (by automatic machines), fully manual (by human operators), and semi-automatic (by collaboration between human operators and automatic machines). Most of the current studies on visual inspection have been focused on the improvement of automatic detection performance by developing a better automatic machine using computer vision technologies. However, there are still a range of situations where human operators should conduct visual inspection with/without automatic machines. In this situation, human operators'performance of visual inspection is significant to the successful quality control. However, visual inspection of components assembled into a mobile camera module belongs to those situations. This study aims to investigate human performance issues in visual inspection of the components, paying more attention to human errors. For this, Abstraction Hierarchy-based work domain modeling method was applied to examine a range of direct or indirect factors related to human errors and their relationships in the visual inspection of the components. Although this study was conducted in the context of manufacturing mobile camera modules, the proposed method would be easily generalized into other industries.

Water Quality Modeling of the Eutrophic Transition Zone in a River-Type Reservoir Paldang (부영양화된 하천형 호소(팔당호) 전이대의 수질모델링)

  • Kong, Dongsoo
    • Journal of Korean Society on Water Environment
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    • v.30 no.4
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    • pp.429-440
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    • 2014
  • This study was conducted to investigate the main cause of water quality deterioration during the spring season in the transition zone between the South Han River and the river-reservoir Paldang. A water quality model modified from QUAL2E (U.S.EPA) was used, and the model showed that eutrophication and algal production in the low flow season affected about 60% of the organic pollution at the downstream of the South Han River. This result means that phosphorus control is prior to external organic material management to ameliorate the deterioration of water quality in the water body.

An Empirical Study about Assessment of the JIT System: on korean semi-production firm

  • Lee, Eung-Kweon
    • International Commerce and Information Review
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    • v.7 no.2
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    • pp.75-94
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    • 2005
  • This study is focused on evaluating the computer-integrated just-in-time (CI-JIT) production system of a semi-conductor manufacturing firm in Korea. Approaching the mid-1980s, the emphasis was on low price, low-cost operations, and quality, especially in USA. American companies have shifted output to low-wage countries like the Philippines, Korea, Japan, Malaysia and allied countries that can make quality products at low prices. Korea and other Asian countries forego short-term profits to gain a solid foothold in a product market, recognizing that larger market share leads to lower cost and higher profit in the long run. They bring manufacturers and suppliers together to improve material management and operation management, using project teams that investigate topics, such as Just-In-Time(JIT)manufacturing, among others. The "Kanban" word means "card" in Japanese, and is used to indicate the desired final delivery schedule. The operation for a particular item produced is scheduled for a specific time. The same process is extended to the external suppliers. More recently, the cards are gradually being replaced by electronic procedures that follow the same concept. Its capacity must be capable of handling the various transactions required by the JIT coverage as well as some allowances for expanded applications.

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Simulation of a piezoelectric flextentional deep-water sonar transducer using a coupled FE-BEM (결합형 유한요소-경계요소 기법을 사용한 심해저용 압전형 유연성 쏘나 변환기의 시뮬레이션)

  • Jarng Soon Suck;Lee Je Hyeong;Ahn Heung Gu;Choi Heun Ho
    • Proceedings of the Acoustical Society of Korea Conference
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    • spring
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    • pp.218-223
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    • 1999
  • A piezoelectric flextentional deep-water sonar transducer has been simulated using a coupled FE-BEM. The dynamics of the sonar transducer is modelled in three dimensions and is analyzed with extern리 electrical excitation conditions as well as external acoustic pressure loading conditions. Different results are available such as steady-state frequency response for RX and TX, displacement modes, directivity patterns, back-scattering patterns, resonant frequencies, bandwidths, quality factors, transmitting voltage (TV) responses, input receiving sensitivity (RS) responses. White the present barrel-stave typed sonar transducer of the piezoelectric material is being simulated, the external surface of the transducer is modified in order to allow the same water pressure to be applied to the inner and the outer surfaces of the transducer. With this modification for deep-water application, the resonance frequency of the modified flextentional sonar transducer becomes much lower than that of the unmodified flextentional sonar transducer. The results of the present sonar transducer modelling are also compared with those of a commercial package such as ATILA.

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