• 청정기술
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• 제18권2호
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• pp.200-208
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• 2012

본 연구는 공단지역 주민들의 환경오염물질에 의한 건강피해를 예방하기 위한 기초연구의 일환으로 수행되었다. 이를 위하여 공단지역 및 대조지역에 대한 토양 중의 환경오염물질과 다환방향족탄화수소화합물(PAHs)의 농도수준 및 분포특성을 조사하였다. 시료채취는 공단지역과 대조지역의 토양을 대상으로 실시하였으며, 토양 중의 중금속, VOCs(휘발성 유기화합물), PAHs 및 PCB(폴리클로리 네이티드비페닐) 등 토양오염물질 농도를 분석하였다. 직접노출군에 속하는 가까운 거리의 송도동, 해도동, 제철동 등은 거리가 먼 장기면에 비하여 비교적 높은 농도를 나타났다. 특히 배출원 주변의 직접노출지역(제철동)이 대조지역(장기면) 보다 오염물질의 농도가 높은 것으로 조사되었다. 토양 중의 중금속 농도는 제1지역 우려기준에 비해 대체로 낮은 것으로 나타났으나, 아연은 전 지역이 제1지역 우려기준(300 mg/kg)의 약 20.8~58.9% 수준으로 비교적 높은 농도를 나타내었다. 불소는 모든 지점에서 기준치 이하로 나타났으나, 직접노출지역인 제철동의 경우 제1지역의 우려기준(400 mg/kg)의 약 74% 수준으로 조사되어, 불소에 대한 모니터링과 배출원 관리가 필요한 것으로 판단된다. 또한, 유기인, PCB, 페놀류와 VOCs인 벤젠, 톨루엔, 에틸벤젠, 자일렌 등은 분석기기의 검출한계 이하로 나타났고, 석유계총탄화수소(TPH)의 경우에는 송도동이 높게 나타났다. 한편, 토양 중 PAHs 화합물의 농도 수준은 18.71~1744.59 ng/g이었으며, 발암가능물질 6종에 대한 PAHcarc의 농도수준은 6.54~695.94 ng/g을 나타내었다. 송도동에서 가장 높은 농도수준을 나타내어, 직접노출지역인 공업단지로부터 근거리 지점에서의 PAHs 농도가 원거리 지점인 간접노출지역보다 비교적 높은 농도를 나타내었다.

• 한국정보통신학회논문지
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• 제26권9호
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• pp.1272-1278
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• 2022

정부는 2021년 1월에 '중대재해처벌법'을 제정 공포하여, 이 법을 시행하고 있다. 하지만, 2021년 산업재해 사고자수가 전년 동기 대비 10.7% 증가하였다. 따라서, 산업 현장에서는 안전대책이 시급한 현실이다. 본 연구에서는 통신 환경이 열악한 고위험 산업현장의 안전관리를 위하여 BLE Mesh 네트워킹 기술을 적용한다. 복합 센서 AIoT 디바이스로 가스 센싱값, 음성, 모션값을 실시간으로 수집하여, 인공지능 LSTM 알고리즘과 CNN 알고리즘을 통해 정보값을 분석하여 위험 상황을 인식하고, 서버에 전송한다. 서버에서는 전송 받은 위험정보를 실시간으로 모니터링 하여 즉각적인 구호조치가 수행되도록 한다. 본 연구에서 제안하는 AIoT 디바이스와 안전관리 시스템을 고위험군 산업 현장에 적용함으로써, 산업재해를 최소화하고 사회안전망 확대에도 기여할 것이다.

• 대한안전경영과학회지
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• 제14권2호
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• pp.49-54
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• 2012

As all kind of industry has developed, metal structure and machine instrument use bolt, pin, rivet and welding for assembly and combination. For pin and hinge, dimension accuracy is crucial to keep the operation and safety of the structure and machine instrument. In case of complex machine, the hinge for cover open-loop system is one of the significant design elements. Most of the hinges are being imported and assembled sine they give high technology development cost for its unit cost position. The reason is that the localization of hinge is inadequate. As the demand increase and the necessity of localization grow, it is now more important than ever to develop low cost structure. By the low cost structure, a new technology could be obtained for electronic product and structural hinge since it would enable for complex machine hinge to be guaranteed, technologically. Open-loop hinge is the link type and designed for the structure to keep constant open-loop. And, the hinge is examined in design stability by finite element analysis method. In this paper, the operation result is presented when the hinge for complex machine open-loop is designed for link type structure.

• 대한기계학회논문집A
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• 제25권4호
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• pp.610-618
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• 2001

Pantograph, which collects current from cartenary system, is one of the important parts of high-speed train. Kinematic analysis is one of the key technologies for pantograph design and includes joint trajectories, reaction forces, and the required moment of main shaft calculations. The kinematic analysis, however, is very complex and time-consuming process. In this study PC based pantograph kinematic analysis software using graphical user interface tool was developed for the easy evaluations of kinematic characteristics necessary in pantograph design process.

• 소성∙가공
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• 제28권6호
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• pp.321-327
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• 2019

In this study, a hot and cold forging process was investigated to produce a complex-shaped hub of dual clutch transmission with low material loss and high productivity. The process was designed by the commercial finite element (FE) analysis program, DEFORM-2D (hot forging) and 3D (cold forging). And, the material flow and ductile fracture characteristics were studied to check the surface crack initiation of the specimen. The simulation results indicated that the proposed process could manufacture the complex-shaped hub with no surface crack and high-efficiency compared to the conventional machining process. For verification the numerical results, the hub of the SCM440 was fabricated by the proposed process and the mechanical properties and microstructure evolution were studied. It was demonstrated that the suggested hot and cold forging process might be useful in producing the key components of the automobile industry as a high-efficiency and environmentally friendly process.

• Journal of Power Electronics
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• 제16권1호
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• pp.153-162
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• 2016

Given their structural arrangement, photovoltaic (PV) modules exhibit parasitic capacitance, which creates a path for high-frequency current during zero-state switching of the converter in transformerless systems. This current has to be limited to ensure safety and electromagnetic compatibility. Many solutions that can minimize or completely avoid this phenomenon, are available. However, most of these solutions are patented because they rely on specific and often complex converter topologies. This study aims to solve this problem by introducing a solution based on a classic converter topology with an appropriate modulation technique and passive filtering. A 5.5 kW single-phase residential PV system that consists of DC-DC boost stage and DC-AC H-bridge converter is considered. Control schemes for both converter stages are presented. An overview of existing modulation techniques for H-bridge converter is provided, and a modification of hybrid modulation is proposed. A system prototype is built for the experimental verification. As shown in the study, with simple filtering and proper selection of switching states, achieving low leakage current level is possible while maintaining high converter efficiency and required energy quality.

• 청정기술
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• 제17권4호
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• pp.379-388
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• 2011

본 연구는 공단지역의 대기 시료를 이용하여 다환방향족 탄화수소(Polycyclic Aromatic Hydrocarbons, PAHs)의 농도수준, 분포특성 및 생체 중 농도에 관하여 조사하였다. 시료는 공단지역 및 주변지역 4개 지점에서 채취하였으며, 지역적 특성에 따라 다환방향족 탄화수소(PAHs) 농도의 변화를 다음 결과에 나타내었다. 공단지역의 대기 중 다환방향족탄화수소화합물 (PAHs)의 평균농도 수준은 $14.52{\sim}193.48ng/m^3$로 조사되었다. 발암가능물질 6종 PAHcarc.의 평균농도 수준은 $1.65{\sim}13.44ng/m^3$로 나타났다. 농도 수준은 대체적으로 낮았지만 제철동지점은 지속적인 관심이 필요한 지역으로 조사되었다. 모든 지점의 대기 시료에서 벤조(a)피렌(Benzo(a)pyrene)의 검출이 확인되었으나 농도는 높지 않았다. 그러나 제철동 지점에서 벤조(a)피렌(Benzo(a)pyrene)의 농도는 $2.89ng/m^3$로 유럽연합(EU)의 기준($1ng/m^3$)을 초과하는 것으로 나타났다. 직접노출군 240명의 전혈 중 다환방향족탄화수소화합물(PAHs) 농도수준을 조사한 결과, 남자의 경우 $1.12{\sim}11.45ng/m^3$, 여자의 경우 $1.20{\sim}26.89ng/m^3$로 조사되었다. 성별에 따른 차이는 거의 없는 것으로 나타났다. 고령자의 혈중 다환방향족탄화수소화합물(PAHs) 농도가 높게 나타나 생체 축적성을 예측할 수 있었다. 본 연구결과 공단지역 및 주변지역은 다환방향족탄화수소 화합물(PAHs) 및 환경오염물질의 영향을 받고 있는 지역으로 공단지역에 대한 환경오염물질 원인배출원에 대한 감시체계의 보완, 집중관리, 지역 주민의 건강 보호를 위하여 보건 환경성질환에 영향을 미치는 위해인자 및 오염물질을 원천적으로 저감하는 작업이 지속적으로 수행되어야 할 시점이다.

• 센서학회지
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• 제29권5호
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• pp.342-347
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• 2020

In this study, a portable total-phosphorus (TP) monitoring system utilizing a photocatalytic-reaction-based pretreatment method is proposed, fabricated, and characterized. Commercial TP monitoring systems are only used in laboratories because of their complex monitoring procedure, bulk-size, and high-cost. In particular, pretreatment in commercial TP monitoring systems is performed at high temperatures (> 120 ℃) and pressure (> 1.1 kg cm^-2) making it difficult to minimize the scale of the systems. The proposed TP monitoring system employs a pretreatment method with a photocatalytic reaction; thus, its size can be reduced, as photocatalytic reactions occur at room temperature and atmospheric pressure. Analytes with various TP concentrations are pretreated using the proposed portable TP monitoring system and are quantitatively measured with an LED and a photodiode.

• 방사선산업학회지
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• 제17권1호
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• pp.101-110
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• 2023

Radiation and radioisotopes have a high value in terms of utilization that can be used in convergence with various fields. However, due to the specificity of radiation, the use of radiation and radioisotopes is more difficult than in other industrial fields and also involves complex regulations. There are no clear industrial technology standards in these fields. Therefore, the growth of the radiation industry, especially including small companies, is being delayed. Since industrial technology standards play an important role in providing an institutional basis for the continuous development and settlement of domestic technology, the development of technical standards for the radiation and radioisotope industries can lead to systematic growth of the domestic radiation industry. To this end, the technology classification of the radiation industry was promoted and classified into 7 major categories, and detailed classification was divided according to the characteristics of each technology. In addition, a demand and perception survey on the need for industrial technology standards was conducted on RI licensed institutions and companies, and as a result, 61.4% responded that it was necessary, and in particular, they recognized the need for radiation safety(63.3%). In this paper, the technical classification for the radiation field is presented as the first step in the development of industrial technical standards for the radiation industry. In addition, the plan of the current status information and preparation of standard procedures of each category will be discussed.

• 한국산업경영시스템학회:학술대회논문집
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• 한국산업경영시스템학회 2002년도 춘계학술대회
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• pp.51-56
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• 2002

A Korea next-generation high-speed rail system represents a typical example of large- scale multi-disciplinary systems, consisting of subsystems such as train, electrical hardware, electronics, control, Information, communication, civil technology etc. The system design and acquisition data of the large-scale system must be the subject under strict configuration control and management. The system therefore, must be developed using systems engineering that is a efficient and effective methodology to design such a complex system and manage its development. This paper presents the results from a computer-aided systems engineering application to the Korea next generation high-speed railway project. Especially, the focus of the study was on requirement management and PBS management.