• 한국산학기술학회논문지
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• 제16권4호
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• pp.2602-2608
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• 2015

본 연구는 고춧가루의 HACCP(Hazard Analysis Critical Control Point) 시스템 적용에 필요한 미생물학적 위해 요소분석을 위한 목적으로 2014년 1월 10일~2014년 6월 13일까지 충주시 동량면 소재에 있는 용금농산에서 수행하였다. 고춧가루 제품의 모든 공정 단계들을 파악하여 공정흐름도를 작성하였고 미생물학적 위해를 제어할 수 있는 자외선살균공정에서 살균 시간을 변화시키면서 미생물의 변화를 시험한 결과 자외선 등 $20W{\times}12EA$, 살균 시간은 $63{\pm}3$초를 한계기준으로 결정하였다. 자외선살균 후에는 위해 미생물 검사 결과는 안전하나 제조환경과 작업자의 미생물 검사 결과 주기적인 세척 및 소독을 실시하여 미생물학적 위해를 감소시키고 작업자 위생교육 등을 통하여 개인위생을 준수해야 할 것으로 판단된다.

• 한국비블리아학회지
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• 제12권1호
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• pp.43-64
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• 2001

본 연구는 대학도서관서비스에 대한 고객만족도를 측정하여 고객 지향의 도서관 운영방안을 마련하려는 목적으로 수행되었다. 그 결과를 요약하면 다음과 같다. 서비스의 질 속성 총 55개 문항에 대한 고객의 만족도를 5점 척도로 조사한 결과, 만족도가 가장 높은 것은 대출 반납의 신속성이었고, 그 다음은 연체료처리, 도서관의 위치, 검색시스템의 용이성과 도서관이용교육, 검색속도, 검색 단말기수, 청결 상태의 순 이었다. 반면, 만족도가 가장낮은 것은 불만처리 속도이었고, 그 다음은 프로그램 사용시간, 민원처리 결과와 도서관이용교육의 정례화, 홍보방법, 인터넷이용의 대기시간, 비 소장자료의 이용의 순 이었다. 또한 대학도서관의 고객이 특히 중요시하는 서비스 부문은 서가에서의 자료 획득 가능성, 학습시설, 장서의 적절성 도서대출, 검색시스템 등이었다. 대학도서관에서는 이런 면에 관심을 갖는다면 고객만족을 더욱 높일 수 있을 것이다.

• 산업경영시스템학회지
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• 제41권1호
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• pp.59-69
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• 2018

The up-to-date business environment for Korean manufacturers is very complex and rapidly changing. Especially, the companies have faced with various changes derived from small quantity batch production, diversification of customer demands, and short life cycles of products. Consequently, the Korean manufacturing companies are in need of more efficient production planning and scheduling techniques. In this paper, the research trend of scheduling techniques is investigated to provide relevant information to researchers in this field. Furthermore, some implications for future researches are presented regarding literatures published in Korea over the last 10 years. This paper presents an entire investigation into Korean research works on scheduling (2,569 papers) that are published from 2007 to 2016. Especially, detailed analysis was carried out in the following three industry : 1) semiconductor, 2) shipbuilding and 3) automobile. In this paper, approaches to scheduling presented in the literature are categorized into the following three categories : 1) application, 2) algorithm, and 3) simulation modeling. First, in the semiconductor industry, scheduling techniques related to semiconductor cleaning processes, photolithography processes, chemical processes, transport and transport equipment have been found to be dominant. Second, the shipbuilding industry is focused on assembly processes, transporter, crane and various existing production management system. On the other hand, the scheduling research of the automobile industry is mainly focused on the vehicle movement routing and procurement supply-chain planning algorithm in terms of logistics. The conclusion of this study are expected to provide many implications for various types of academic and practical follow-up studies related to scheduling in consideration of main characteristics of semiconductor, shipbuilding and automobile industries.

• Restorative Dentistry and Endodontics
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• 제37권1호
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• pp.24-28
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• 2012

Objectives: The aim of this study was to test the hypothesis, that the effectiveness of irrigation in removing smear layer in the apical third of root canal system is dependent on the depth of placement of the irrigation needle into the root canal and the enlargement size of the canal. Materials and Methods: Eighty sound human lower incisors were divided into eight groups according to the enlargement size (#25, #30, #35 and #40) and the needle penetration depth (3 mm from working length, WL-3 mm and 9 mm from working length, WL-9 mm). Each canal was enlarged to working length with Profile.06 Rotary Ni-Ti files and irrigated with 5.25% NaOCl. Then, each canal received a final irrigation with 3 mL of 3% EDTA for 4 min, followed by 5 mL of 5.25% NaOCl at different level (WL-3 mm and WL-9 mm) from working length. Each specimen was prepared for the scanning electron microscope (SEM). Photographs of the 3mm area from the apical constriction of each canal with a magnification of ${\times}250$, ${\times}500$, ${\times}1,000$, ${\times}2,500$ were taken for the final evaluation. Results: Removal of smear layer in WL-3 mm group showed a significantly different effect when the canal was enlarged to larger than #30. There was a significant difference in removing apical smear layer between the needle penetration depth of WL-3 mm and WL-9 mm. Conclusions: Removal of smear layer from the apical portion of root canals was effectively accomplished with apical instrumentation to #35/40 06 taper file and 3 mm needle penetration from the working length.

• 반도체디스플레이기술학회지
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• 제12권3호
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• pp.19-22
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• 2013

The purpose of this study is to develop a system that can monitor the amounts of energy consumption during CVD and etching process for semiconductor manufacturing. Specifically, this system is designed to measure the $CO_2$ emission amounts quantitatively by measuring the flow rate of gas used and amount of power consumed during the processes. The processes of CVD equipment can be classified generally into processing step and cleaning step and all the two steps were monitored. In CVD and etcher equipments, various gases including Ar and $O_2$ are used, but Ar, $O_2$ and He were monitored with the use of the LCI data of Korea Environmental Industry & Technology Institute and carbon emission coefficients of EcoInvent. As a result, it was found that the carbon emission amounts of CVD equipment for Ar, $O_2$ and He were $0.030kgCO_2/min$, $4.580{\times}10^{-3}kgCO_2/min$ and $6.817{\times}10^{-4}kgCO_2/min$, respectively and those of etcher equipment for Ar and $O_2$ are $5.111{\times}10^{-3}kgCO_2/min$ and $7.172kgCO_2/min$, respectively.

• 한국진공학회지
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• 제20권2호
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• pp.86-92
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• 2011

본 연구에서는 새롭게 개발된 센서인 in-situ particle monitor (ISPM)와 기존센서의 기능을 업그레이드 한 센서인 self-plasma optical emission spectroscopy (SPOES)를 이용해 화학기상증착 진공공정을 진단하였다. 본 연구에서 사용된 증착공정 장비는 silane 가스를 이용한 silicon plasma enhanced chemical vapor deposition과 borophosphosilicate glass 증착장비이다. 두 장비의 증착 또는 클리닝 조건에서의 배출되는 오염입자와 배기가스를 개발된 센서를 이용해 공정상태를 실시간으로 진단하는 것과 개발된 센서의 센싱 능력을 검증하고자 하는 목적으로 연구가 진행되었다. 개발된 센서는 장비 배기구 설치되었으며, 공정압력, 유량, 플라즈마 파워 등의 공정변수 변화에 따른 오염입자 크기 및 분포와 배기 부산물의 변화를 측정하고, 측정 결과의 상호 연관성을 분석하였다.

• 멤브레인
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• 제4권4호
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• pp.213-220
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• 1994

정유산업 방출폐수를 재처리하여 양질의 공업용수로 활용하고자 역삼투막 및 공정으로 구성된 재활용 system을 고안하여 현장 pilot 실험을 수행하였다. 생산공정 운전상황에 따라 불규칙적으로 변하는 폐수 특성에도 불구하고 역삼투막의 경우 10~15$kg/cm^2$의 운전압력 범위내에서 96~99%정도의 비교적 높은 염배제율을 보였으며 본 실험을 통하여 얻은 재생수의 경우 냉각탑 공급용수로써의 충분한 가능성을 보여 주었다. 그러나 본 연구에서 제안 사용된 여과형 전처리 공정만으로는 충분한 처리효율을 기대하기 어려웠으며, 이는 각 여과공정법 처리수의 수질분석 결과 및 NaOH를 이용한 역삼투막 세정 결과로부터 쉽게 확인되었다.

• Journal of information and communication convergence engineering
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• 제9권4호
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• pp.475-482
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• 2011

In this research, we have attempted to estimate the water quality of fish farms in terms of parameters such as water temperature, dissolved oxygen, pH, and salinity by employing observational data obtained from a coastal ocean observatory of a national institution located close to the fish farm. We requested and received marine data comprising nine factors including water temperature from Korea Hydrographic and Oceanographic Administration. For verifying our results, we also established an experimental fish farm in which we directly placed the sensor module of an optical mode, YSI-6920V2, used for self-cleaning inside fish tanks and used the data measured and recorded by a environment monitoring system that was communicating serially with the sensor module. We investigated the differences in water temperature and salinity among three areas - Goheung Balpo, Yeosu Odongdo, and the experimental fish farm, Keumho. Water temperature did not exhibit significant differences but there was a difference in salinity (significance <5%). Further, multiple regression analysis was performed to estimate the water quality of the fish farm at Keumho based on the data of Goheung Balpo. The water temperature and dissolved-oxygen estimations had multiple regression linear relationships with coefficients of determination of 98% and 89%, respectively. However, in the case of the pH and salinity estimated using the oceanic environment with nine factors, the adjusted coefficient of determination was very low at less than 10%, and it was therefore difficult to predict the values. We plotted the predicted and measured values by employing the estimated regression equation and found them to fit very well; the values were close to the regression line. We have demonstrated that if statistical model equations that fit well are used, the expense of fish-farm sensor and system installations, maintenances, and repairs, which is a major issue with existing environmental information monitoring systems of marine farming areas, can be reduced, thereby making it easier for fish farmers to monitor aquaculture and mariculture environments.

• 상하수도학회지
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• 제25권1호
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• pp.95-106
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• 2011

Even though MBR processes have many advantages such as high quality effluents, a small footprint and convenience for operation compared to conventional activated sludge processes, there are some shortcomings in terms of the cost and potential fouling incident that keeps MBR (Membrane bioreactor) processes from being widely applied. To reduce these problems, PTFE (Polytetrafluoroethylene) flat sheet membranes that have excellent permeability and durability were tested instead of PVDF (Polyvinylidene fluoride) membrane which is being used widely in water treatment. Low concentration of sodium hydroxide (NaOH) was also added into the membrane modules in order to prevent the membrane fouling as well as to provide the alkalinity. With conditions mentioned above, a pilot-scale MBR system based on the MLE (Modified Ludzack Ettinger) process was operated at flux of 40 $L/m^{2}/hr$ and over 15,000 mg/L MLSS concentration for about 8 months. And coagulant(alum) was added into the membrane tank to remove phosphorus. Although the more coagulant is added the more effectively phosphorus is removed, that can lead to fouling for a long operation(Ronseca et al.,2009). By the way there is a research that fouling grow up after stopping injection of coagulant(Holbrook, 2004). Stable operation of MBR systems was achieved without major chemical cleaning and the effluent quality was found to be good enough to comply with the treated waste water quality regulations of the Korea.

• 한국정밀공학회지
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• 제17권8호
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• pp.180-188
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• 2000

Fine multi-hole sheet metal product(FMSMP) is a specific metal plate which is used in color TV and computer monitor. Processes of manufacturing FMSMP are generally composed of coating cleaning exposure and etching processes. After a thin metal plate is made by rolling photosensitive liquid is coated on the metal plate in coating process. Then the coated thin metal plate consecutively passes through exposure process in which upper and lower glasses are compressed by vacuuming the space between glasses and metal plate. In this lowered glasses are compressed by vacuuming the space between glasses and metal plate. In this lowered vacuum state certain part of metal plate is desirably exposed to light and will be etched into forming lots of well-arranged holes with a specific diameter, nowadays to manufacture FMSMP of 17 inch braun tube 80 second is required for complete vacuum but 35 second is applied to manufacture FMSMP in reality. In the present study vacuuming time is tried to reduce for improvement of productivity by analyzing vacuum system and proposing several solutions, for faster vacuuming speed degree of vacuum state between glasses and metal plate is improved by the proposed method and experiments using the proposed method are performed for verification. In addition microstructure of FMSMP is investigated to prevent stain phenomena and to improve quality of the product.