• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2014.05a
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• pp.919-920
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• 2014

따개비(barnacle)는 선저부에 붙어서 번식하며 딱딱한 석회질 껍데기로 덮여있다. 이로 인하여 선박의 속도를 저하시키고 도료기능을 상실시키는 주요인이 된다. 이를 제거하기 위해 작업자가 직접 액체를 분사하고 브러쉬로 세척해야 한다는 불편함과 위험에 노출되기 때문에 선박작업용 로봇이나 기계들이 많이 개발되고 있다. 현재 연구 중이거나 개발이 완료된 것 중에는 영구자석 또는 전자석 휠을 사용하거나 공압을 이용하여 수직벽면에서 작업을 한다. 특히 공압 방식을 많이 사용하였는데 수직벽면에 로봇이 밀착될 만큼 강한 공압이 필요하게 되기 때문에 부가적인 장치가 많이 필요하다. 본 논문에서는 부가적인 장치를 최소화하고 효과적인 동작을 하기위해 전자석 방식을 선택 하였으며 간편하게 선박의 수직벽면을 작업할 수 있는 전자석 방식의 4륜 로봇을 개발하고자 한다. 선박의 수직벽면 작업용 4륜구동 로봇을 전자석을 이용하여 수직벽면에 부착할 수 있도록 설계하였으며 자력의 세기와 방향을 제어하여 로봇이 선박의 수직면에 밀착되어 자유롭게 이동이 가능하도록 개발 하고자 한다.

• Journal of ILASS-Korea
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• v.28 no.3
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• pp.126-133
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• 2023

This study analyzes the flow characteristics and sponge ball recovery performance in a ball strainer according to vortex promoter design variables through flow-particle analysis based on actual experiments to derive a method for improving the recovery rate of cleaning sponge balls of CTCS applied to existing power plants. Based on the ball strainer in CTCS used in the power plant, the experiment was conducted by changing the design factor of the improved shape. In addition, flow and particle analysis were performed under the same conditions as the experiment to numerically the flow characteristics and recovery rate in the ball strainer according to the design factor of the vortex promoter. As a result of the study, it was confirmed that the recovery performance was improved by about 3% by changing the design height of the Vortex promoter. And when comparing the difference between maximum and minimum recovery rate, it was found that the effect on the recovery performance increased slightly according to the distance condition compared to the vortex promoter design height condition.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.7
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• pp.1154-1161
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• 2004

The objective of this study was to evaluate microbiological Quality of HACCP application in elementary school foodservice operations. Microbiological Quality of utensils and non-heated foods such as salad was measured two times at five elementary schools in Daegu. The two experimentations differed in that after the first experimentation employees were educated and trained on HACCP based sanitation standards with a goal of improving microbiological Quality of foodservice. Microbiological Quality, time, and temperature were evaluated at three critical control points (CCPs)： washing and disinfecting, personal hygiene and non-cross contamination. Micro-biological Quality was assessed using 3M petrifilm to measure total plate count and coliform group. The first experimentation showed low microbiological Quality due to cross contamination of utensils and cooking gloves; high microbiological count of the garlic, powdered red pepper, and ginger; and not thoroughly washing and disinfecting vegetables. In the second experimentation, microbiological Quality was greatly improved by washing and thoroughly disinfecting raw ingredients and utensils, and using good personal hygiene. However, microbiological Quality of seasonings was still low. Immediate corrective actions were required in one of the foodservice operations that was assessed. These results strongly suggest that foodservice operations should address non-heated food Quality. It is essential to measure microbiological Quality regularly and continually train and retrain employees on hand washing and disinfecting raw ingredients. Further studies are needed to determine whether pathogens are present in raw vegetables and seasonings.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.8
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• pp.478-488
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• 2017

Stormwater filtration is widely used for the urban runoff treatment. However, intensive maintenance and lack of information about the performance have resulted in an increased need of proper evaluation. In this study, the performance of an upflow stormwater runoff filtration system, consisting of a supporting unit and a filtration unit filled with a ceramic media, was investigated. The maximum head loss increase was about 3 cm under the suspended solid (SS) load of $30kg/m^2$ and the SS removal was more than 96%, when the filtration velocity was 20-40 m/h. The head loss and the porosity of the media can successfully be described by a power model. It was confirmed that the a significant amount of SS can effectively be removed at supporting unit, minimizing SS load to the filter media bed. Several backwashing strategies have been tested to establish the optimum condition. It was found that the stagnant water discharge is important to minimize the SS release immediately after backwashing. Also, the filter bed loaded with $400-450kg/m^2$ SS can almost completely be washed to reduce the head loss to the that of empty bed. The results in this study indicate that the upflow ceramic media filter is an excellent alternative to stormwater treatment, with high SS removal and long lifespan.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.4
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• pp.566-574
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• 2001

For decades it has been a clinically accepted requirement, in case of salivary contamination, to re-etch conditioned enamel and dentin to proceed with the adhesive technique. Only a few reports have been so far dealing with the potential of one-bottle adhesive system to bond even when applied after salivary contamination and without re-etching. The purpose of this study was to evaluate the influence of the salivary contamination on the shear bond strength of dentin. The results were as follows: 1. In group II, in which saliva contamination and washing occurred before applying of Prime & Bond NT showed high shear bond strength as in control group. In Group III and IV, in which the cured adhesive was contaminated with saliva, showed significantly lower mean bond strength, 2. Relating long resin tags of $70\sim120{\mu}m$ were observed in samples of all groups under SEM. We could observed hybrid layer, resin tag and many lateral branches in every group. And there were no differences between groups.

• Journal of Wetlands Research
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• v.20 no.4
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• pp.417-423
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• 2018

It analyzed the efficiency of the runoff reduction of artificial reservoir by analyzing the influent and effluent of reservoir located downstream of the livestock area. Production of non point pollutants in livestock feeding areas, which is located at steep slope land, was mainly due to first flushes. Suspended Solid concentration of influent increased due to amount of rainfall, and T-P also increased over four times and 30 % of total nitrogen increased on average compared to those of dry season. While the concentration of nitrate nitrogen showed little variation, ammonia nitrogen increased over two times. The storage style nonpoint reduction facility showed the highest removal efficiency of 53 % for total phosphorus in dry weather, when the removal efficiency was 37 % for suspended solids, 10% for organic compounds, and 5 % for total nitrogen. Since algal bloom grows due to eutrophication in summer, the minus removal efficiencies of nitrogen concentration through the reservoir occurred with high frequency. Removal efficiency decreased during rainfall, showing 60 % for supended solids, and 22 % for total phosphorus. While having over nine times of capacity than the standard of non-point removal facility from Ministry of Environment, it was impounded with water during rainy season, showing not enough nonpoint removal efficiency, which indicates that maintenance is also an important factor to the nonpoint removal efficiency.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.264-264
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• 2017

국외의 상수도 원격검침 시스템 내 데이터 전송방식은 도시 규모, 계량기의 밀도, 전력공급 여부 및 통신망의 설치 여부 등을 종합적으로 고려하여 결정되었다. 대부분의 스마트워터미터 제조업체들은 계량기의 부호기가 공급하는 판독 내용(데이터)을 전송할 검침단말기와 근거리 통신망(neighborhood area network)을 연계하여 개발 및 판매하였으며, 자체 소유 통신 프로토콜을 사용하여 라디오 주파수(RF) 통신 기술을 사용하고 있다. 광역통신망(wide area network)의 경우, 노드(말단의 계량기 및 센서)들과 이에 연결된 통신망 들을 포함한 네트웍의 배열이나 구성이 스타(star), 메쉬(mesh), 버스(bus), 나무(tree) 등의 형태로 통신망이 구성되어 있으나, 스타와 메쉬형 통신망 구성형태가 가장 널리 활용되는 것으로 조사되었다. 시스템 통합운영관리 업체들인 IBM, Oracle, Itron 등은 용수 인프라 관리 또는 통합네트워크 솔루션 등의 통합 물관리 시스템(integrated water management system)을 개발하여 현장적용을 하고 있으며, 원격검침 시스템을 통해 고객들의 현재 소비량과 과거 누적 소비량, 누수 감지 서비스 및 실시간 요금 고지 등을 실시간으로 웹 포털과 앱을 통해 제공하고 있다. 또한, 일부 제조업체들은 도시 용수공급/소비 관리자가 주민의 용수사용량을 모니터링하여 일평균 용수사용량 및 사용 경향을 파악하고, 누수를 검지하여 복구 및 용수 사용 지속가능성 지수를 제시하고, 실시간으로 주민의 용수사용량 관련 데이터를 모니터링하여 용수공급의 최적화를 위한 의사결정지원 서비스를 용수공급자에게 제공하고 있다. 최근에는 인공지능을 활용해 가정용수의 용도별(세탁용수, 화장실용수, 샤워용수, 식기세척용수 등) 사용량 곡선을 패터닝하여 profiling 기법을 도입해, 스마트워터미터에서 용수사용량이 통합되어 검지될 시 용수사용량의 세부 용도별 re-profiling 기법을 도입하여 가정용수내 과소비되는 지점을 도출 후 절감을 유도하는 기술이 개발 중이다. 또한, 미래 용수 사용량 예측을 위해 다양한 시계열 자료를 분석하는 선형 종속 모형(자기회귀모형, 자기회귀이동평균모형, 자기회귀적분이동평균모형 등)과 비선형 종속 모형(Fuzzy Logic, Neural Network, Genetic Algorithm 등)을 활용한 예측기능이 구축되어 상호 비교하여 최적의 용수사용량 예측 도구를 제공되고 있다.

• Science of Emotion and Sensibility
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• v.10 no.1
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• pp.55-68
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• 2007

This paper describes a Voice User Interface(VUI) method and a design guideline tool which supports the studies for domestic appliance. This issue covers specification of user requirement and selection of appropriate VUI to represent speech generation. The criteria for paper is interaction design to enhance user engagement. The studies were carried out to measure prototype of domestic appliance such as a refrigerator, a washing machine, a Gimchi refrigerator, an oven range, a dishwasher and an air conditioner. This paper is presented a study of user preferences and suitability. The results of these findings to voice interface design are discussed and it is suggested that VUI guideline and optimal prototyping can provide a useful application tools in the design process.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.4
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• pp.2602-2608
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• 2015

The aim of this research was microbiological hazard analysis which is required to application of HACCP(Hazard Analysis Critical Control Point) system to chili powder. A processing had been conducted in Yong-Geum Agricultural Production located in Dongnyang-myeon, Chungju-si between January 10, 2014 to June 13, 2014. A manufacturing process chart was prepared by entire level of processing. A changes of microorganism was tested by changing sterilization time in ultraviolet ray sterilization processing which can control microbiological Hazard. As a result, critical Limits is decided as ultraviolet rays lamp $20W{\times}12EA$, sterilization $63{\pm}3$ min of each. The result of the microorganism test after ultraviolet ray sterilization was safe. On the other hand, a microorganism test of manufacturing environment and workers suggested that the microbiological hazard should be reduced through systematic cleaning and disinfection accompanied by personal hygiene based on hygiene education on workers.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.34 no.4
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• pp.179-188
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• 2011

This paper outlines a systematic guideline for remanufacturing process using the Failure Mode and Effect Analysis (FMEA) method in order to estimate the reliability and quality of the remanufactured alternator. The method is just a tool to help, but the remanufacturer must determine the optimal remanufacturing process and specific inspection and production that will turn the alternator as-good-as new and place the product into the market with reliability and quality equal to a new product. FMEA is a method that is widely used in industry and has shown its value and effectiveness in the above remanufacturing case study. Actions taken often result in a lower severity, occurrence or detection rating. Redesign may result in lower severity and occurrence ratings while inserting validation controls and maintenance can reduce the detection rating. The revised ratings are recorded with the originals on the FMEA template form. After these corrective actions and revisions have been established, evaluation of the ranks can be repeated, until the redesign and control parameters comply with safety standards.