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        검색결과 892

        81.
        2021.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study is to analyze the adequacy of production capacity of the assembly process system of mobile bath vehicle’s top box panel and process design through a simulation analysis. Towards this end, the layout of the facility designed with pre-verification job using a simulation modeling and an experiment, and facility, logistics process, and personnel input method were made into a simulation model, and the design system’s adequacy was evaluated through an experiment. To produce 120 mobile bath vehicles annually, it was analyzed that 14 general workers and seven skilled workers were adequate through the experiment. It was also identified that three painting process lines carried out through outsourcing were adequate. Production lead time was 201.7 hours on average and it was 230 hours maximum. To meet customer delivery service level of 95% within the deadline when establishing a customer order and vehicle delivery plan, it was analyzed that more than 215 hours of lead time is needed minimum. If the process cycle time is reduced to 85% upon system stabilization and skillfulness improvement, it was analyzed that annual output of 147 vehicles can be achieved without additional production line expansion.
        4,000원
        83.
        2021.05 구독 인증기관 무료, 개인회원 유료
        3,000원
        85.
        2021.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The role of QR Code robots in smart logistics is great. Cognitive robots, such as logistics robots, were mostly used to adjust routes and search for peripheral sensors, cameras, and recognition signs attached to walls. However, recently, the ease of making QR Codes and the convenience of producing and attaching a lot of information within QR Codes have been raised, and many of these reasons have made QR Codes recognizable as visions and others. In addition, there have been cases in developed countries and Korea that control several of these robots at the same time and operate logistics factories smartly. This representative case is the KIVA robot in Amazon. KIVA robots are only operated inside Amazon, but information about them is not exposed to the outside world, so a variety of similar robots are developed and operated in several places around the world. They are applied in various fields such as education, medical, silver, military, parking, construction, marine, and agriculture, creating a variety of application robots. In this work, we are developing a robot that can recognize its current position, move and control in the directed direction through two-dimensional QR Codes with the same horizontal and vertical sides, and the error is to create a QR Code robot with accuracy to reach within 3mm. This paper focuses a suggestion of control method in QR Code-aware indoor mobility robots.
        4,000원
        87.
        2021.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Salivary gland adenocarcinoma(AdCa NOS) is one of the major causes of mortality among malignant salivary gland tumors. New therapeutic measure are needed to improve the outcome for patients with AdCa NOS because current therapy does not significantly improve survival rates. Transglutaminase 2(TGase 2) was implicated in forming cross-linked protein polymer, apoptosis and matrix interaction. And also TGase 2 expression is up-regulated in proliferation, migration, invasion, and metastasis of cancer cells. shRNA which has emerged as an effective method to target specific genes for silencing has provided new opportunities for cancer therapy. But there has been rarely reported using shRNA-TGase 2 transfection in AdCa NOS. The purpose of this study were to examine the specific inhibition of TGase 2 mRNA and protein expression by siRNA transfection of TGase 2 through RT-PCR and immunoslot blotting, and to study proliferation, migration and invasion assay of SGT cell line from AdCa NOS. Cell cycle analysis showed that the downregulation of shRNA-TGase 2 caused the accumulation of cells in the sub-G0/G1 phase. In migration assay, suppressing shRNA-TGase 2 inhibited the capacity of the cells to migrate compared to parental cells. In invasion assay, cells transfected with shRNA-TGase 2 decreased in invasion when compared to SGT and vector transfected cells. shRNA-TGase 2 expressing plasmids efficiently downregulated TGase 2 mRNA and TGase 2 protein expression. It suggested that the shRNA-TGase 2 targeting system against TGase 2 could have a therapeutic potentiality for malignant salivary gland tumors, especially in inhibiting and/or preventing cancer cell proliferation, migration and invasion.
        4,000원
        90.
        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
        91.
        2021.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Machines and facilities are physically or chemically degenerated by continuous usage. The representative type of the degeneration is the wearing of tools, which results in the process mean shift. According to the increasing wear level, non-conforming products cost and quality loss cost are increasing simultaneously. Therefore, a preventive maintenance is necessary at some point . The problem of determining the maintenance period (or wear limit) which minimizes the total cost is called the ‘process mean shift problem’. The total cost includes three items: maintenance cost (or adjustment cost), non-conforming cost due to the non-conforming products, and quality loss cost due to the difference between the process target value and the product characteristic value among the conforming products. In this study, we set the production volume as a decreasing function rather than a constant. Also we treat the process variance as a function to the increasing wear rather than a constant. To the quality loss function, we adopted the Cpm+, which is the left and right asymmetric process capability index based on the process target value. These can more reflect the production site. In this study, we presented a more extensive maintenance model compared to previous studies, by integrating the items mentioned above. The objective equation of this model is the total cost per unit wear. The determining variables are the wear limit and the initial process setting position that minimize the objective equation.
        4,000원
        92.
        2021.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        목적 : 정상안에서 조도에 따른 눈의 굴절력과 동공 크기의 동적변화를 측정하고, 동공 중심점의 이동량과 방향을 알아보고자 하였다. 방법 : 2020년 7월부터 2020년 9월까지 경기도 지역 안경원에 원용 안경 처방을 위해 내원했던 안과적인 질환 및 각막 굴절 교정 수술 경험 없는 성인 29명(남 14명, 여 15명) 58안을 검사하였고, 평균 나이는 35.62±14.48세였다. 전자동 수차 분석기를 이용하여 조도에 따른 눈의 굴절력, 동공 중심점의 변화 값을 측정하 였고, 각각 3회씩 측정하여 평균값을 사용하였다. 통계 프로그램 SPSS를 이용하여 조도 변화에 따라 명소시와 암소시에서의 굴절력, 그리고 동공 중심의 이동량을 비교 분석하였다. 결과 : 조도에 따라 구면 굴절력은 –2.80 D에서 -2.94 D로 평균 –0.14 D 만큼 변화하였다(p<0.001). 원주 굴 절력은 –0.93 D에서 -0.98 D로 평균 –0.05 D가 증가하였다(p<0.001). 동공 중심점의 평균 이동량은 수평 방향으로 0.14 mm, 수직 방향 0.13 mm만큼 이동하였다. 방향 별 동공 중심점 이동은 양안에서 상측 35안(60.3%), 하측 20안(34.5%), 코측 25안(43.1%), 귀측 33안(56.9%) 이동하였다. 양안에서 동공 중심점 이동은 수평방향으 로 높은 상관관계가 있었고(r=0.700), 수직방향으로는 낮은 상관관계가 있었다(r=0.244). 결론 : 조도가 어두워질수록 구면굴절력은 (-)방향으로 커지고, 동공 크기가 증가하며, 동공 중심은 수평과 수직 방향으로 모두 이동하였다. 따라서 야간 활동 안경렌즈를 조제할 때는 굴절력 변화와 동공 중심 이동에 따른 시력의 질적 저하를 고려해야 할 것으로 생각된다.
        4,000원
        93.
        2021.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The role of QR code robots in smart logistics is great. Cognitive robots, such as logistics robots, were mostly used to adjust routes and search for peripheral sensors, cameras, and recognition signs attached to walls. However, recently, the ease of making QR codes and the convenience of producing and attaching a lot of information within QR codes have been raised, and many of these reasons have made QR codes recognizable as visions and others. In addition, there have been cases in developed countries and Korea that control several of these robots at the same time and operate logistics factories smartly. This representative case is the KIVA robot in Amazon. KIVA robots are only operated inside Amazon, but information about them is not exposed to the outside world, so a variety of similar robots are developed and operated in several places around the world. They are applied in various fields such as education, medical, silver, military, parking, construction, marine, and agriculture, creating a variety of application robots. In this work, we are developing a robot that can recognize its current position, move and control in the directed direction through two-dimensional QR codes with the same horizontal and vertical sides, and the error is to create a QR code robot with accuracy to reach within 3mm. This paper focuses on the driving operation techniques during the development of QR code-aware indoor mobility robots.
        4,000원
        94.
        2021.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In order to collect basic information of response behavior of red seabream (Pagrus major) during pilling, works for constructing wind power station in Byeonsan Peninsular, Korea were investigated. Four cultured red seabream CRB1 to CRB4 [total length (TL): 27.1 ± 1.0 cm; body weight: 359 ± 30 g] were tagged with an acoustic tag and used in experiment. CRB1 and CRB2 to CBR4 were released on the sea surface at same time around the constructing site of the wind power plant on September 22, 2017 and July 18, 2018, respectively. The tracking of the CRB1 to CRB2 and CRB3 to CRB4 were conducted for two hours, approximately, using VR100 receiver including a directional hydrophone and VR2W receivers array consisted of 19 presence/absence receivers (VR2W receivers), respectively. The underwater noise level before (no pile driving works) and during pile driving works was measured 116.0-118.0 dB (re 1Pa) and a maximum of 160 dB (re 1Pa), respectively. CRB1 moved about 6.0 km with average swimming speed of 80.2 ± 20.5 cm/s for 2.1 hours without pile driving work. The average water depth of the sea bed on the route of CRB1 was 9.1 ± 0.4 m. CRB2 moved about 7.3 km with the average swimming speed of 96.8 ± 27.1 cm/s for 2.1 hours with pile driving work. The water depth of the sea bed on the route of CRB2 was 11.9 ± 0.6 m. At results of the Rayleigh’s z-test two fishes CRB1 and CRB2 showed significant directionality in the movement (p < 0.01). Movement mean angles of CRB1 and CRB2 were 92.7 and 251.8°, respectively. CRB2, CRB3 and CRB4 exhibited the escaping behavioral response from the noise of source during the pile driving work. The swimming speed of the CRB2 exposed on the heavy underwater noise stimuli due to the pile driving work was 1.21 times faster than that of the CRB1 exposed on the ambient underwater
        4,200원
        95.
        2021.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The role of QR code robots in smart logistics is great. Cognitive robots, such as logistics robots, were mostly used to adjust routes and search for peripheral sensors, cameras, and recognition signs attached to walls. However, recently, the ease of making QR codes and the convenience of producing and attaching a lot of information within QR codes have been raised, and many of these reasons have made QR codes recognizable as visions and others. In addition, there have been cases in developed countries and Korea that control several of these robots at the same time and operate logistics factories smartly. This representative case is the KIVA robot in Amazon. KIVA robots are only operated inside Amazon, but information about them is not exposed to the outside world, so a variety of similar robots are developed and operated in several places around the world. They are applied in various fields such as education, medical, silver, military, parking, construction, marine, and agriculture, creating a variety of application robots. In this work, we are developing a robot that can recognize its current position, move and control in the directed direction through two-dimensional QR codes with the same horizontal and vertical sides, and the error is to create a QR code robot with accuracy to reach within 3mm. This paper focuses on the moving control model during the development of QR code-aware indoor mobility robots.
        4,000원
        96.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        벼는 동남아에서 매우 중요한 작물이며 작물 재배면적의 대부분을 차지하고 있다. 벼 생산량 증대를 위해 주요 문제 해충인 멸구류를 방제하는 것이 중요하다. 방제 방법으로는 농약을 이용한 방제가 주를 이루고 있는데, 규정상 농약은 공인 된 등록약제를 사용하도록 되어 있다. 그러나 동남아 주요 벼 재배국가의 방제 농약의 정보는 국내에 알려져 있지 않기 때문에 멸구류 방제용 등록 약제를 소개한다. 1. 등록 약제는 국가별로 소폭 차이는 있으나 그 계통이 네오니코티노이드계가 가장 많은 비중을 차지한다는 점에서 공통점을 보였다. 이러한 특성 때문에 동일 약제의 연용으로 인한 저항성 발현 문제가 잠재되어 있다고 판단된다. 2. 이는 동남아만의 문제가 아니라 장기적으로는 기류를 타고 멸구류가 비래해오는 우리나라에도 영향을 줄 수 있다는 것을 시사하고 있다. 3. 따라서 향후 동남아 국가간 공동방제 등 상호협조가 필요하며, 농촌진흥청에서 추진하고자 하는 AFACI 사업을 통해 국가별 약제저항성 검정 및 방제 표준화기술 확립 등과 같은 지원에 협력을 해주어야 할 것으로 판단된다.
        4,000원
        97.
        2020.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        감염병의 전파는 환자와의 접촉이 중요한 전파 경로이기 때문에 개인 차원에서의 활동 정보는 감염 위험성을 파악하는데 중요한 지표로 활용될 수 있다. 이 연구는 코로나바이러스감염증-19 (COVID-19) 확진자의 이동 특성을 파악하는 방안을 제시하는 것이 목적이다. 이를 위해서 시간지리학 개념을 적용한 지리적 시각화 프로토타입 환경을 구축하여 서울시의 코로나 확진자 이동경 로 데이터를 분석하였다. 지리적 시각화 프로토타입에서는 코로나바이러스감염증-19 확진자의 시간대별 방문 장소를 3차원 경로로 시각화하였다. 또한 방문장소별 방문시간과 체류시간은 정거장 개념을 반영한 원통으로 표현하여 확진자별 방문 장소의 중복 여부를 파악할 수 있었다. 이 연구에서 제안하는 시각화 방법은 다음과 같이 활용될 수 있다. 첫째, COVID-19 확진자 이동 자료의 시공간적 범위와 특성을 동시에 시각화함으로써 시공간적 이동 특성을 분석할 수 있다. 둘째, COVID-19 확진자 이동경로에 있는 정거장 시각화를 통해서 확진자 접촉가능 장소를 파악할 수 있다.
        4,000원
        98.
        2020.12 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        본 연구는 스마트건설 지원을 위한 드론 활용의 활성화를 위해 RTK 드론 기반의 항공측량 정밀도를 분석하고자 GPS만을 사용하는 방식, GCP를 설치하는 방식, RTK 드론을 이용한 방식의 정사영상의 위치정확도를 분석하였고 사업의 목적과 대상지의 형태에 따른 드론 활용의 기준을 제시하였다. 또한 상용 드론을 이용한 체적기반의 토공량 산출을 2.5D 환경에서 산출하여 기존 방법과 비교해서 드론영상을 효율적으로 활용할 수 있는 방법을 제시하였다. 본 연구로 대규모 건설현장의 작업효율 및 드론 활성화가 기대된다.
        4,000원
        100.
        2020.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        최근 전 세계적으로 지진 발생빈도가 급증하면서 초고층 건축물에 다양한 피해가 발생하고 있다. 특히 고층 건물에 가해지는 수평하중이 구조물의 주요 구조요소 뿐만 아니라 외부 패널의 파손으로 유리 외장재가 낙하하는 등 2차 피해가 발생할 수 있다. 이러한 문제의 심각성을 고려하여 비구조 요소에 대한 2차 손상 방지 방안을 마련하는 것이 필요하다. 본 연구에서 는 기존 건축물 외부 패널이 가진 문제점에 대하여 실대형 시험과 유한요소 해석을 토대로 구조적 성능을 분석하고 취약부를 도출하였으며, 이를 보완하기 위해 층간 분리형 커튼월 모듈과 이동형 패스너를 적용한 커튼월 모듈에 대한 유한요소해석을 수행하였다. 해석결과를 바탕으로 기존 커튼월과 비교시 구조적 안정성을 확보할 수 있는 것으로 확인되었다.
        4,300원
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