• Journal of the Ergonomics Society of Korea
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• v.28 no.4
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• pp.83-89
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• 2009

This study was conducted to assess exposure to musculoskeletal disorders risk factors in the cooking & housekeeping jobs in hotel work. PATH (posture, activity, tools and handling) method was used for data collection at the 6 hotel settings in different regions across Korea. From 26 workers, a total of 949 PATH observations were obtained. The highest percent time on non-neutral posture was 78% for pinch grip, followed by 74%(wrist deviation), 52%(trunk posture), 37%(shoulder/arm posture), and 30%(neck posture). The highest percent time in the three HAL variables was 47% for HAL-cat2. The percent time of items in relation to both loads with more than 5kg and contact stress was less than 2%. The hotel workers were not exposed to vibration.

• The Transactions of the Korean Institute of Power Electronics
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• v.22 no.3
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• pp.193-198
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• 2017

This paper discusses the design and control of a switched reluctance motor (SRM) drive system for a built-in car vacuum cleaner. The growing popularity of outdoor activities and recreation has led the automobile industry to expand technologies that increase the convenience of vehicles, and thus, a built-in car vacuum cleaner was introduced. However, the existing DC motor of a vacuum cleaning system has several disadvantages, such as maintenance cost and lifespan issues of its commutator-brush structure. An SRM can be a good alternative to the existing DC motor because of its high-speed capability, long lifespan, low maintenance cost, and high efficiency, among other advantages. A prototype SRM drive is designed and manufactured to verify its feasibility for use in a built-in car vacuum cleaning system. Dynamic simulation is conducted to determine the optimal switching angle for maximum efficiency and minimum torque ripple. Load test, noise measurement, and suction-power tests are also carried out.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.3
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• pp.741-746
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• 2015

Recently, as mobile operating system market and wireless communication technology have been rapidly developed, many devices such as smart phones, air conditioners, smart TVs, cleaning robot, and cameras become available with android operating system. Accordingly, collecting variety of information through many everyday use devices with network connections is now enabled. However, in the current market, most devices are controlled individually developed applications, and there is growing need to develop a master application that can control multiple devices. In this paper, we propose and implement a system that can control multiple android-based devices on a Wired/Wireless router(AP) registered through web server. we expect such an effort can attribute to future IoT researches.

• The Journal of the Convergence on Culture Technology
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• v.8 no.1
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• pp.379-384
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• 2022

The year 2021 is a monumental year for the history of Korean cinema that inferiority of the sci-fi genre, by the appearance of two sci-fi blockbuster films- produced by Netflix and produced by TVing-at the same time. Coincidentally, both of movies are sci-fi films which appear post-human such as robot and clone. As can be seen in 『Frankenstein』 story, the progenitor of science fictions, the mankind have imagined beings similar to humen or post-human who are another human being for a long time. deals with the unusual subject matter of a space scavenger and a space janitor, and the main character is a robot that very familiar with human. is the story of a man who lives for a limited life protects and accompanies a clone named Seobok who was created as a test subject. This film deals with the philosophical themes like death and eternal life through the existential concerns of two characters. use Korean Shinpa -Korean specific senimental code-sentiment on narrative, and has the character of a road movie set in Korea's geographical space.

• Journal of Chest Surgery
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• v.40 no.11
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• pp.786-788
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• 2007

Primary malignant fibrous histiocytoma of the lung is extremely rare, A 12-year-old child was admitted to the hospital due to an incidentally detected lung mass. A $2.5{\times}2.5 cm$ sized mass located in the right lower lobe was seen on the chest X-ray, the chest computed tomogram and the positron emission tomogram. We resected the mass through a right lateral thoracotomy and the mass was revealed to be a malignant spindle cell neoplasm on the frozen section diagnosis. So, we performed lobectomy of the right lower lobe with systemic dissection of the mediastinal lymph nodes; the final histopathological diagnosis of the mass was malignant fibrous histiocytoma. The patient was discharged on postoperative day 7 and adjuvant chemotherapy was not applied.

• Journal of the Korea Convergence Society
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• v.5 no.3
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• pp.23-27
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• 2014

In recent times, there is an increasing interest in wireless charge of smartphones and devices, and many companies are developing wireless charges. The range of application of wireless charge would be expanded to almost all electronics, including not only mobile devices, but also notebook computers and vacuum cleaners. On-line electric vehicles are to be launched in the market this year in a massive scale. As such wireless charge-related markets are inexhaustible. Wireless charge is included in the world's top 10 promising technologies, and its rapid growth is expected to have annual growth by more than 100%. However, there's a need to establish a safe environment, by analyzing security threats to technical limitations and harmfulness to human body, and arrange institutional compliments. The development of communication method for a variety of wireless charging are delivering comfortable and safe information. This paper aims to examine the factors to threaten electric vehicle, which are usually intruded through network system and analyzes security threats to and security requirements for magnetic resonance mode-based wireless charge in mobile devices, and suggests security requirements.

• Journal of The Korean Society of Grassland and Forage Science
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• v.26 no.3
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• pp.159-170
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• 2006

This study was conducted to investigate the effects of two dry matter levels of liquid swine manure on dry matter yield and nutritive value of Italian ryegrass, rye and oats, and the chemical characteristics of soil in Jeju. This experiment tested in split plot design. Three forage crops (Italian ryegrass, rye and oats) were the main plot and four fertilizers (no fertilizer=T0, chemical fertilizer=T1, liquid swine manure with DM 2.7%=T2 and liquid swine manure with DM 5.9 %=T3) were the sub plots. Yield and nutrient contents of forage crops and soil properties were determined. Application of liquid swine manure containing 5.9% dry matter resulted in highest DM yield in all three forage crops species compared with the other treatments (p<0.01). Crude protein content(%) and crude protein yield(kg/ha) of forage crops were highest in rye compared with the other forage crops species(p<0.01). K and Mg contents of soil were higher(p<0.01) in rye than in the other species while Na contents was higher(p<0.01) in Italian ryegrass than others. Mg content of soil appeared higher in rye than in the others and higher(p<0.05) in forage crops applied with liquid manure containing 2.7% DM compared with the other species. $NO_3-N$ contents in soil was lower in rye than the other species and higher in species with chemical fertilizer. These findings indicate that most of liquid swine manure produced on local pig farms containing low levels of dry matter and other nutrients suggest a low efficiency of its use as a fertilizer. The liquid swine manure is recommended as a fertilizer for rye production in winter, compared with Italian ryegrass or oat.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2017.04a
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• pp.34-34
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• 2017

목질계바이오매스 중 목재펠릿은 '탄소중립(Carbon Neutral)' 연료로써 온실가스 감축 의무에 대응 가능한 에너지원이다. 하지만 목질계바이오매스 연소 시 발생되는 타르는 보일러 내부에 누적되어 효율을 감소시킨다. 타르 및 연소 불꽃에 의한 효율 감소를 최소화하기 위해 반대측면에 내화재(Castable)를 적용하여 실험하였으며 시뮬레이션을 이용하여 구조변경 분석이 실시되었다. 적용된 내화재는 비중이 낮고 단열성이 우수하여 열손실을 막아 연료비 절감의 효과를 가져 오며, 연소실 내부 청소 면적 감소로 인한 경제적 효과도 기대 할 수 있다. 분석결과를 이용하여 최적화된 펠릿보일러가 제작되었으며, 실험을 통하여 200시간 가동 후 열효율 감소량이 나타났다. 단위시간별 동일한 외부환경(산화제량, 부하, 주변 온도, 펠릿소비량)에서 실험이 진행 되었으며, 타르생성이전(Non-tar), 이후(Tar-existence) 보일러의 열효율 성능 비교실험이 실시되었다. 실험결과 타르생성이전 조건에서 구조변경 전 후 보일러의 열효율은 각각 91.87%, 90.73%로 확인되었으며, 타르생성이후 조건에서 각각 82.68%, 83.27%의 열효율을 확인하였다. 타르생성이전 대비 이후 조건에서 열효율 감소량은 각각 9.19%p, 7.46%p로 구조변경 전 대비 변경 후 보일러의 열효율이 약 1.73%p 더 적게 감소됨을 확인되었으며, 시뮬레이션 결과 타르생성이전 조건에서 구조변경 전 후 보일러의 효율은 각각 91.83%, 92.05%로 확인되었으며 타르 생성이후 조건에서 각각 85.25%, 87.43%의 열효율을 확인하였다. 타르생성이전 대비 이후 조건에서 열효율 감소량은 각각 6.58%, 4.62%로 구조변경 전 대비 변경 후 보일러의 열효율이 약 1.96%p 더 적게 감소됨을 확인하였다.

• Journal of Korean Society of Environmental Engineers
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• v.38 no.7
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• pp.343-352
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• 2016

Effects of grinding time and chemicals dosage in arsenic removal from contaminated paddy soil in China were investigated using lab scale attrition and froth flotation combining process. Arsenic concentration in the field soil was 76.51 mg/kg, exceeding Korean and Chinese standards, and predominant arsenic compounds fraction in sequential extraction was "residual" (over 80%). After wet sieving, soil with >2 mm and < 0.038 mm showed concentration lower than 'Warning Level' in Korea. Soil with 0.038-0.075 mm, showing the highest concentration, was discarded since it occupied minor weight fraction (10.1%). Thus soil between 0.075 and 2 mm was only used in the combining process. The highest Arsenic concentration in progeny fragments smaller than 0.038 mm reached up to 981.66 mg/kg after 5 min of attrition. Optimal dosage of collector ($C_5H_{11}OCS_2K$) and modifier ($Na_2S$ and $CuSO_4$) in froth flotation process for the selective separation of the chipped progeny particles from the parent fragments were determined both as 200 g/ton. Arsenic removal efficiency in froth flotation process was 38.47% and it was increased to 72.74% in additional flotation process, scavenging. Average arsenic concentration after overall process - wet sieving, attrition and froth flotation - was estimated to 16.45 mg/kg.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.2
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• pp.9-14
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• 2020

Four developed patents have applied for a new type of Composite Cyclone Scrubber followed by the previous research (Cho and Kim, 2017), including dust reducing fan with filters. Regarding target installation and maintenance cost, 64% reduction for investment costs (6.2 billion won vs. 17 billion won) compared to existing road pollution reduction system, while social benefit costs increase by 43% compared to existing road pollution reduction measures (72.6 billion won vs. 50.8 billion won). The composition of the device is an air blower type spiral guide vane, and an injection pressure collecting dust efficiency. A nozzle varies Injection angle and contact range, spray liquid species (waterworks, salty water). The proposed patent tests are circulation water Time-by-Time Spray and collected 41.4% more increased micro dust since the sprayed water meets contaminated gas due to the 45° degree colliding, which is 141% increased conventional dust collector. (Ratio of collection over 85%). As regards the source of collection liquid, circulated rainwater and well water, we expect a huge amount of energy and economically saved eco-friendly system in our patent. Finally, the guided vane and metal filter reduced over 90% micro-dust, while sprayed water cleans the vane and filters, resultantly minimizing the maintenance budget. The preliminary evaluations of the developed design make it possible to reduce not only cheaper maintenance budget due to the characteristic water spraying but the cost of water comes from mainly rain and underground.