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        검색결과 72

        2.
        2023.11 구독 인증기관·개인회원 무료
        In the dismantling of nuclear power plants, various forms of radioactive gaseous waste are generated when cutting concrete and metal structures. Large amounts of radioactive dust and aerosols generated during the cutting process of each structure can cause radiation exposure to the environment around the workplace and to the radiation exposure in the body of workers. When cutting structures, water is sprayed to reduce the generation of aerosols, so early saturation of the filter is expected due to radioactive aerosols and fine particles containing a large amount of moisture. A mobile air purification device is being developed to a fast and efficient air purifier that can be used for a long time operation to protect workers from radiation exposure in high radiation areas and to minimize the amount of secondary waste generated. In this paper, the direction for a new concept of unit technology that can achieve the development purpose is described.
        3.
        2023.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Although the proportion of coal-fired power generation is decreasing, efficient operating technology is needed to continuously invest in facilities and reduce maintenance costs until it is abolished. Boilers, one of the main facilities of power plants, operate for a long time in harsh environments of high temperature and high pressure. In addition, damage due to deterioration is likely to occur depending on the fuel and tube material used. It is very important to judge soundness because damage caused by deterioration adversely affects facility operation. Previously, replication method was used to analyze the progress of deterioration. In the replication method, pre-treatment such as chemical treatment is performed on the boiler tube in the field, the area is reproduced by attaching a film, and the replicated film is determined by an expert in the laboratory with an expensive microscope. However, this method involves substantial costs and time requirements, as well as the possibility of human errors. To address these issues, we developed a mobile health assessment system in this research. Since it is detachable and takes images in real time, this system enables swift evaluations across a broad range and facilitates the assessment of preprocessing quality. In addition, it was intended to reduce existing human mistakes by developing a degradation classification algorithm using the merger cluster method.
        4,000원
        4.
        2023.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study assessed the measurement technique of odorous substances using a GC/MOS system with MOS sensor at the detector and the method detection limits were determined for odorous substances such as hydrogen sulfide, acetaldehyde, toluene, m,pxylene, and o-xylene. The portable GC/MOS system was able to separate and measure about 16 out of 22 odorous substances including sulfur compounds, aldehydes, and VOCs. The peak values for hydrogen sulfide, acetaldehyde, toluene, m,p-xylene, and o-xylene showed a nonlinear relationship with concentration and a correlation coefficient of 0.95 or higher was confirmed. The method detection limits for hydrogen sulfide, acetaldehyde, toluene, m.pxylene, and o-xylene using the portable GC/MOS system were determined to be 0.005, 0.023, 0.016, 0.004, and 0.051 ppm, respectively. It is expected that the system can measure odor samples with concentrations of least 50 ppb without additional pretreatment or concentration processes.
        4,000원
        6.
        2023.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Background: The Natural killer cell activity measurement test of the ELISA method developed by company A could have many economic benefits in terms of cost and time compared to the existing 'cytotoxicity test method'. A portable incubator capable of culturing the specimen while moving was developed as a way to save test time and secure the stability of the specimen when transferring the specimen to the entrusted institution. Objectives: This study investigated efficacy evaluation of NK cell activity measurement in a portable incubator. Design: Experimental research. Methods: 100 participants were selected to measure NK cell activity. The collected blood was placed in a general incubator and a portable incubator at the same time to start culturing, and the plasma was separated by centrifugation. The NK cell activity test was measured by enzyme immunometry. Results: In the verification of the culturing performance of the developed portable incuvator, no significance was found between the general incuvator and the portable incuvator, and the same performance was maintained in culture. Conclusion: Portable incubators have a great effect on shortening the test time and securing the stability of samples.
        4,000원
        8.
        2022.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        작물 수분스트레스 지수(CWSI; Crop Water Stress Index)를 통해 관개 시기를 판단할 경우, 정확한 잎의 온도 및 대기 환경을 측정하는 것이 중요하다. 그리하여 본 연구에서는 실시간으로 작물의 생체정보(엽온) 및 대기 환경(대기온·습도, 일사량)을 측정하고 자동으로 CWSI 값이 산정되는 휴대용 수분스트레스 계측기기를 개발하였다. 또한 휴대용 수분스트레스 계측기기와 고정식 온도 측정 방법과의 비교 분석을 통해 휴대용 수분스트레스 계측기기의 성능을 평가하고자 하였다. 본 계측기기는 CWSI 산정을 위한 생체신호 및 기상 데이터를 측정하는 센싱부, 측정된 데이터를 저장하고 CWSI를 산정하는 데이터 수집부, 장치의 기능을 조작하고 측정값을 표시하는 시스템 제어부로 구성하였다. T-test를 실시하여 두 계측 방법에서 측정된 엽온, 일사량, CWSI 평균값의 유의 관계를 분석한 결과, 유의확률은 0.089, 0.318 그리고 0.028로 각각 나타났다. 엽온과 일사량은 유의수준 0.05보다 크므로 유의미한 차이가 나타나지 않았지만 CWSI는 유의확률이 유의수준보다 작으므로 두 측정 방법에 따라 유의미한 차이가 나타났다.
        4,000원
        9.
        2021.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        PURPOSES : The retroreflectivity of pavement markings for road safety was evaluated. METHODS : Field tests of pavement markings, which are characters, symbols, crosswalks, and stop lines, but do not include line markings, were conducted using a portable retroreflectometer with the purpose of evaluating the retroreflectivity according to the type of pavement markings and roads. Furthermore, changes in retroreflectivity due to wheel passing and wet conditions were evaluated. Here, 192 test points for evaluating the retroreflectivity of pavement markings, 5 test points for evaluating reductions in retroreflectivity during conditions of wetness, and 28 test points for checking variability due to type of testing device were selected on major and minor arterial roads in Seoul. RESULTS : The average retroreflectivity of pavement markings measured in this study was 115.7 (mcd/m2·lux), which is lower than the minimum retroreflectivity required six months after installation but higher than the minimum remarking retroreflectivity required by Seoul city. The retroreflectivity of pavement markings measured on minor arterial roads was 69.1% of that on major arterial roads. The average retroreflectivity of pavement markings was reduced to 43.1% by wheel passing, which is below the remarking criterion. The average retroreflectivity measured on wet pavement markings was 43.7 (mcd/m2·lux), which is a ninth of that under dry conditions. The test results showed that retroreflectivity in the rain was much lower than the required value in the case of rain, which is 175 mcd/m2·lux, as issued by Seoul city. Compared with mobile retroreflectometers, a portable retroreflectometer produced 17% higher retroreflectivity based on the results of 28 test points. CONCLUSIONS : Based on the field tests, the retroreflectivity of pavement markings, i.e., characters, symbols, crosswalks, and stop lines, was higher than the average remarking criterion. However, the retroreflectivities of pavement markings passed by the wheel or in rain were lower than the remarking criteria. Considering that the remarking criteria in Seoul city are higher than those in Europe and the test results in this study indicate much lower values than those required in Seoul, further study is necessary to be able to properly modify the criteria for retroreflectivity.
        4,000원
        10.
        2021.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The leading source of occupational fatalities is a portable ladder in Korea because it is widely used in industry as work platform. In order to reduce victims, it is necessary to establish preventive measures for the accidents caused by portable ladder. Therefore, this study statistically analyzed injury death by portable ladder for recent 10 years to investigate the accident characteristics. Next, to monitor wearing of safety helmet in real-time while working on a portable ladder, this study developed an object detection model based on the You Only Look Once(YOLO) architecture, which can accurately detect objects within a reasonable time. The model was trained on 6,023 images with/without ladders and safety helmets. The performance of the proposed detection model was 0.795 for F1 score and 0.843 for mean average precision. In addition, the proposed model processed at least 25 frames per second which make the model suitable for real-time application.
        4,000원
        11.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        목적 : 본 연구에서는 다양한 방법들을 이용하여 토릭렌즈 마킹 회전량을 평가할때 일치도를 평가측정하고자 하였다. 방법 : 모형안과 콘택트렌즈 착용이 가능한 57안(평균 24.79±1.29세)을 대상으로 토릭소프트렌즈를 제조사의 가이드라인에 따라 피팅한 후, 사진 촬영, 각도기 어플리케이션, 휴대용 돋보기와 세극등 현미경을 사용하여 회전 평가를 진행했을 때의 서로 다른 검사자 간의 검사 결과값을 비교 분석하였고, 서로 다른 회전평가 방법 간의 일 치도는 블랜드 알트만 분석을 사용하였다. 결과 : 서로 다른 검사자 간 같은 회전평가 방법으로 토릭소프트렌즈의 회전량을 측정하였을 때, 측정값의 평 균 차이가 사진 촬영, 각도기 어플리케이션, 휴대용 돋보기, 세극등 현미경 평가 방법 각각 –0.50, -0.70, -0.30, -0.13°로 유사한 결과를 보였다. 회전평가 방법 간 비교에 대해서는 사진 촬영과 각도기 어플리케이션을 사용했을 때, 허용 오차 범위(5°) 내의 측정값이 각각 74.56%, 75.44%로 비교적 낮은 신뢰도를 보였고 휴대용 돋 보기를 사용한 방법에서는 95.61%로 높은 신뢰도를 보였다. 결론 : 토릭소프트렌즈 처방에서 세극등 현미경을 사용할 수 없어도 사진 촬영, 핸드폰 각도기 어플리케이션, 휴대용 돋보기를 통해 토릭소프트렌즈 회전평가에 대한 임상적으로 유용한 결과를 얻을 수 있다.
        4,200원
        13.
        2020.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 논문에서는 상용코드인 ANSYS CFX를 통한 해양레저 스포츠 및 야외 활동 시 사용 가능한 휴대용 수평축 수차의 유입유속(U) 및 주속비(TSR, Tip Speed Ratio) 변화에 따른 성능해석을 수행하였으며, 해석결과 및 유동장 분석을 통해 설계에 대한 검토 및 장치의 성능을 확인하였다. 또한, 추가적으로 블레이드의 피치각도(αpitch) 변화에 따른 성능해석을 통해 수차의 성능개선에 필요한 데이터를 획득하고자 하였다. 본 논문의 연구 결과 수치해석 케이스 중 주속비 4인 경우, 모든 유입속도 및 블레이드 피치 각도에서 가장 높은 성능을 보였으며, 설계 유속 이하의 일부 조건에서도 설계 출력인 30 W 이상의 출력을 보였다. 그리고 수치해석 케이스 중 가장 높은 출력과 출력계수는 유입유속 1.5 m/s, 블레이드 피치 각도 3°, 주속비 4에서 보였으며, 출력 약 85 W, 출력계수 약 0.30이었다.
        4,000원
        15.
        2020.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This paper suggests a nonlinear pressure consideration scheme through an unsteady pipe network analyzer for leakage detection with a portable pressure wave generator. In order to evaluate the performance of a proposal scheme, linear input pattern has been simulated and experiments had been carried out under both no leakage and one leakage conditions in a reservoir-pipeline-valve system. This method using portable pressure wave generator showed that a leakage can be detected from a reflection where a leakage is originated through time domain analysis. Meaningful similarity in pressure response between nonlinear input pattern and experimental results were found both no leakage and a leakage conditions.
        4,000원
        17.
        2019.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Gas burner has been widely utilized to many industrial fields and personal outdoor activities and so on. Portable small-sized gas burner is, especially, useful in personal outdoor activities. The performance and safety of portable small-sized gas burner is important because it uses gas as fuel. The purpose of this study was to investigate the possibilities of performance improvement of portable small-sized gas burner through flow and structural analysis, respectively. As the results, it showed that mass fraction of butane gas in all cases(Type 1, Type 2, Type 3) was about 12~18% and further safety load of 3 stand leg was below 10 kgf.
        4,000원
        18.
        2019.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        목적 : 본 연구는 목욕서비스 제공자의 편의성, 업무효율성, 안전성 증진을 통한 근골격계질환 발생 위험성 예방 및 감소시킬 수 있는 이동형 목욕보조기기 개발과 이의 효과성 검증에 목적을 두었다. 연구방법 : 목욕서비스 제공자는 광역시 소재 요양병원에서 근무하는 간병인, 요양보호사 24명을 대상으로 하였다. 연구도구는 목욕서비스 제공자와 전문가집단의 의견수렴을 거쳐 개발한 이동형 목욕보조기기 프로토타입을 사용하였다. 사전평가로 Rapid Entire Body Assessment(REBA), Visual Analogue Scale(VAS)를 하였으며, 사후평가로 REBA, VAS, Korean version of Quebec User Evaluation of Satisfaction Assistive Technology(K-QUEST 2.0), 사용자의 주관적 의견을 설문조사하였다. 사용 전후의 REBA와 VAS를 비교하기 위해 t-test로 분석하였으며, 상관관계를 알아보기 위해 pearson 상 관분석을 하였다. 일반적 특성과 종속변수 간의 분석을 위해 ANOVA를 실시하였다. 결과 : 이동형 목욕보조기기 프로토타입을 사용 후 평가결과, 2가지 자세(목욕용품 사용, 샤워기 사용)에서 측정되었던 REBA 조치수준이 ‘높음’에서 ‘낮음’으로 변경되었다. 통증 정도는 보조기기 사용 후 팔을 제외한 모든 항목에서 감소되었으며 전체 평균점수는 통계적으로 유의한 차이를 보였다. 사용 후 만족도 에서는 규격과 무게를 제외한 6개 항목에서 ‘보통’으로 나타났다. 사용 전·후에 따른 종속변수들 간의 상관관계 분석 결과에서는 높은 상관성을 보이지 않았으며 일반적 특성과 종속변수 간의 통계적 유의성 은 없는 것으로 나타났다. 결론 : 본 연구에서 최종 개발한 이동형 목욕보조기기는 목욕서비스 제공자의 신체적 부담을 줄일 수 있을 뿐만 아니라 편의성, 효율성, 안전성도 증진시킬 수 있는 보조기기로서의 역할이 가능하다고 예상된다.
        4,600원
        19.
        2019.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to create a new odor analysis technology that combines the separation technology of GC and the measurement of MOS sensors. The detector of the GC system is replaced with the MOS sensor to analyze various odor compounds. Carrier gas also used air in the normal atmosphere through a micro pump. Therefore, it is possible to develop a portable odor analysis device since no additional cylinder is needed. Retention times for H2S, C7H8, and C2H4O analyzed by the combined GC/MOS system were identified as 1.28 minutes, 3.88 minutes and 1.77 minutes, respectively. Measurement reproducibility of odorous RT was very good at less than 1.2 %RSD. Also, the magnitude of the peak as a result of changes in the concentration of each odor showed a linear proportional relationship. Thus, a new method could be proposed to analyze various odorous substances with the combined GC/MOS system.
        4,000원
        20.
        2019.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In order to increase the production efficiency of the ship and shorten the production cycle, it is important to evaluate the accuracy of the ship components efficiently during the drying cycle. The accuracy control of the block is important for shortening the ship process, reducing the cost, and improving the accuracy of the ship. Some systems have been developed and used mainly in large shipyards, but in some cases, they are measured and managed using conventional measuring instruments such as tape measure and beam, optical instruments as optical equipment, In order to perform accuracy control, these tools and equipment as well as equipment for recording measurement data and paper drawings for measuring the measurement position are inevitably combined. The measured results are managed by the accuracy control system through manual input or recording device. In this case, the measurement result is influenced by the work environment and the skill level of the worker. Also, in the measurement result management side, there are a human error about the lack of the measurement result creation, the lack of the management sheet management, And costs are lost in terms of efficiency due to consumption. The purpose of this study is to improve the working environment in the existing accuracy management process by using the augmented reality technology to visualize the measurement information on the actual block and to obtain the measurement information And a smart management system based on augmented reality that can effectively manage the accuracy management data through interworking with measurement equipment. We confirmed the applicability of the proposed system to the accuracy control through the prototype implementation.
        4,000원
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