• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2016.11a
• /
• pp.158-158
• /
• 2016

최근 화석연료의 고갈과 환경 보전 및 에너지 절약에 대한 관심이 높아짐에 따라 화석연료의 소비를 최소화하고 실내조건을 쾌적하게 유지하려는 연구가 진행되고 있다. 국내의 경우 전체 에너지 소비의 30%이상을 차지하고 있는 건물부문에서의 에너지 소비를 줄이기 위한 활발한 연구가 진행되고 있으며 이에 따른 에너지절약 소재개발이 활발하게 진행되고 있다. 1975년 이후 여러 차례에 걸친 단열강화 조치를 통해 건물에서의 에너지 소모를 줄이고 있었으나 건물의 외벽에 대한 사항으로 한정되어있었고, 또한 건물의 창 면적이 증가함에 따라 창을 통한 열손실량과 열획득량이 더욱 증가하게 되었다. 이러한 문제를 해결하기 위해 열반사유리에 대한 많은 연구가 진행되고 있다. 열반사유리는 근적외선(열선)영역의 빛을 반사시켜 실내의 열손실량 및 외부에서의 열획득량을 감소시켜 에너지의 소비를 줄일 수 있는 유리을 말한다. 이러한 열반사유리은 fresnel 방정식을 통해 빛의 파장대에 따른 반사율 및 투과도를 예측할 수 있는데, 다층박막구조인 Oxide-Metal-Oxide(OMO)구조는 Oxide의 높은 굴절률과 Metal의 낮은 굴절률을 통해 가시광영역대의 높은 투과도와 근적외선 영역의 높은 반사율을 얻을 수 있다. 또한 Metal층을 삽입함으로서 flexible한 코팅이 가능하고, 높은 carrier density와 mobility로 표면 플라즈몬 공명을 통해 특정 파장대의 반사율을 높일 수 있으므로 많은 연구가 진행되고 있다. $TiO_2$는 고굴절률 및 낮은 광흡수성의 특성을 가지는 산화물반도체로 기존의 $In_2O_3$계 산화물에 비해 값이 싸고 높은 안정성과 광촉매특성을 보이므로 외부에 노출된 환경에 적합한 재료이다. Ag는 저굴절률과 낮은 광흡수성을 가지는 재료로 금속층에 적합하다. 본 연구에서는 fresnel 방정식을 통해 반사도 및 투과도를 예측하고 마그네트론 스퍼터링법으로 다층박막을 열선인 적외선 영역에서의 반사율 및 반사 효율을 평가하였다. Index-matching 시뮬레이션을 통해 $TiO_2/Ag/TiO_2$ 다층박막의 투과도와 반사도를 이론적으로 검토하였다. 시뮬레이션 프로그램은 Macleod프로그램을 이용하였고 재료 각각의 굴절률은 Ellipsometry를 이용하여 측정하였다. 두께 40 nm 와 8 ~ 16 nm를 가지는 $TiO_2$층과 Ag층을 각각 RF/DC 마그네트론 스퍼터링법을 이용하여 Glass기판 위에 증착하였다. 직경 3 in 의 $TiO_2$, Ag 소결체 타깃을 이용하였고 스퍼터링 파워는 각각 200 W, 50 W로 설정하였고, 스퍼터링 가스는 Ar가스의 유량을 20 sccm으로 설정하였다. 작업압력은 모두 1 Pa로 설정하였고 타깃 표면의 불순물 및 이물질 제거를 위해 Pre-sputtering을 10분 진행하였다. 박막의 두께는 reflectometer와 Alphastep을 이용하여 측정하였고 Hall effect measurement를 이용하여 비저항, carrier density, mobility등 전기적 특성을 측정하였다. 또한 UV-VIS spectrometer와 USPM-RU-W NIR Micro-Spectrophotometer를 통해 광학적 특성을 측정하였고 계산 값과 비교분석하였다. 또한 열반사 특성을 평가하기 위해 직접 set-up한 장비를 이용하였다. 단열 박스에 샘플을 장착해 적외선 램프를 조사하였을 때의 열 반사효율을 평가하였고, IR Camera를 이용하여 단열 박스 내부의 온도 변화를 관찰하였다.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.41 no.10
• /
• pp.1475-1485
• /
• 2012

This study was conducted in order to understand nutrition teachers (dietitians)' perceptions of barriers to implementation of HACCP system in school foodservices in Gyeongnam, Korea. Questionnaires were distributed to 350 nutrition teachers (dietitians) from November to December of 2009, and 214 were collected and analyzed. The results of this study were as follows. First, nutrition teachers (dietitians) recognized the following as barriers in implementing the HACCP system: 'the status of facilities and utilities'> 'monitoring'> 'work satisfaction'> 'foodservice employees'> 'cooperation of HACCP team'> 'cooperation of persons concerned besides foodservice employees'> 'understanding the HACCP system'. Second, total working experience was found to be the factor most affecting 'cooperation of HACCP team (p<0.01)', 'cooperation of persons concerned besides foodservice employees (p<0.01)', 'foodservice employees (p<0.05)', and 'work satisfaction (p<0.05)'. Further, 'the status of facilities and utilities' was significantly affected by 'construction/reconstruction of kitchen (p<0.01)', 'division of kitchen area (p<0.01)', 'existence of preliminary preparation room (p<0.01)', and 'existence of dishwashing room (p<0.01)'. Third, dietitians perceived the following concerning hindrance factors of the HACCP system according to CCP stage: 'CCP 1'> 'CCP 3'> 'CCP 2, 'CCP 6'> 'CCP 4'> 'CCP 8'> 'CCP 7'> 'CCP 5'. In conclusion, this study showed that nutrition teachers (dietitians) in the Gyeongnam area recognized 'the status of facilities and utilities' from HACCP areas and 'CCP 1 (menu planning)' from CCP stages as the greatest barriers to implementing the HACCP system in school foodservices. To implement the HACCP system successfully in school foodservices, facilities and utilities should be properly equipped, and menu planning training for nutrition teachers (dietitian) should be conducted.

• Journal of the Korean Society of International Agriculture
• /
• v.30 no.4
• /
• pp.292-299
• /
• 2018

In a survey in which farmers were asked about their levels of satisfaction with agricultural machines, Japanese products scored higher than local products by 1.2, 1.3, and 1.4 times for tractors, combine harvesters, and rice transplanter, respectively. Japanese products corresponded to generally high satisfaction levels in terms of operating performance, operability, frequency of breakdowns, and durability, excluding sales price and after-sales services. Effective countermeasures through quality improvement are therefore necessary for Korean products. Furthermore, a survey of dealers showed that the components and consumables for core agricultural machines had high frequencies of breakdowns and repairs. Four major components of tractors represented 85.3% of all breakdowns and repairs, five components of combine harvesters represented 89.6%, and three components of rice transplanters represented 80.5%. Moreover, a comparison of the technological levels between local and imported machines showed that the local machines' levels were at 60-100% for tractors, 70-100% for combine harvesters, and 70-95% for rice transplanters. Small and mid-sized tractors, 4 interrow combine harvesters, and 6 interrow rice transplanters showed similar levels of technology. The results of the analysis suggest that action is urgently needed at a policy level to establish an agricultural machinery component research center for the development, production, and supply of commonly-used components, with the participation of manufacturers of agricultural machines and components, in order to enhance the competitiveness of local manufacturers and to revitalize the agricultural machine market.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.47 no.5
• /
• pp.50-60
• /
• 2010

For the last half a century, the personal computer and software industries have been prosperous due to the incessant evolution of computer systems. In the 21st century, the embedded system market has greatly increased as the market shifted to the mobile gadget field. While a lot of multimedia gadgets such as mobile phone, navigation system, PMP, etc. are pouring into the market, most industrial control systems still rely on 8-bit micro-controllers and simple application software techniques. Unfortunately, the technological barrier which requires additional investment and higher quality manpower to overcome, and the business risks which come from the uncertainty of the market growth and the competitiveness of the resulting products have prevented the companies in the industry from taking advantage of such fancy technologies. However, high performance, low-power and low-cost hardware and software platforms will enable their high-technology products to be developed and recognized by potential clients in the future. This paper presents such a platform for industrial embedded systems. The platform was designed based on Telechips TCC8300 multimedia processor which embedded a variety of parallel hardware for the implementation of multimedia functions. And open-source Embedded Linux, TinyX and GTK+ are used for implementation of GUI to minimize technology costs. In order to estimate the expected performance and power consumption, the performance improvement and the power consumption due to each of enabled hardware sub-systems including YUV2RGB frame converter are measured. An analytic model was devised to check the feasibility of a new application and trade off its performance and power consumption. The validity of the model has been confirmed by implementing a real target system. The cost can be further mitigated by using the hardware parts which are being used for mass production products mostly in the cell-phone market.

• Journal of the korean veterinary medical association
• /
• v.32 no.4
• /
• pp.206-219
• /
• 1996

동물의 전염성 해면형 뇌증에는 양과 염소의 스크래피, 사슴과 엘크의 만성소모형, 밍크의 전염성 밍크 뇌증, 소 및 소과 야생동물의 소 해면형 뇌증 그리고 고양이의 고양이 해면형 뇌증등이 알려져 있다. 전염성 해면형 뇌증의 원인은 알려져 있지 않으며, 스트레인간의 차이는 숙주의 프리온 유전자에 있어서의 대립유전자의 차이에 의존되는 것으로 추정되고 있다. 이러한 동물의 전염성 해면형 뇌증들은 우리나라에서의 발생보고가 없는 해외 가축전염병이며 현재 영국에서 문제되고 있는 소 해면형 뇌증 즉 일명 광우병은 영국에서 1986년 최초로 확인된 새로운 가축전염병으로서 사람의 크로이츠휄트-야콥병과의 어떤 연관 가능성 때문에 수의학계의 관심의 대상이 되고 있는 질병이다. 영국정부 보건장관 스티픈 도렐은 최근(1996년 3월 20일)에 과거 10년 동안 영국의 소에 감염되어 온 소 해면형 뇌증이 사람의 희귀한 뇌 질환인 크로이츠휄트-야콥병의 새로운 스트레인과 관련성이 있는 증거가 있을 수 있는 것으로 과학자문위원회가 믿고 있다고, 영국하원에서 보고한 바 있다. 한편, 영국의 농업장관 더글러스 호그는 영국에서 30개월 이상된 소를 도살할 때에는 모든 뼈를 제거하여야 하며, 모든 포유동물의 조직은 농업용 사료로 사용해서는 아니된다는 새로운 규정을 공표하였다. 그러나 영국의 쇠고기는 안심하고 먹을 수 있다고 발표하면서 만일 문제가 된다면, 영국에서 사육하는 1천 1백만 마리의 소를 전부 도살할 용의가 있다고 하였다. 이러한 영국정부 견해는 다음 날 CNN News 등 세계 각 매스컴을 통하여 보도되었으며, 아직까지 과학적인 증거가 확립된 바는 없지만, 수의학이나 의학적인 사실 확인의 여부를 떠나, 사회 경제적인 문제로 큰 놀라움과 많은 의문사항을 남겨둔 채, 영국산 소와 쇠고기의 수입금지 조치 등 국제적인 문제로 확대되었다. 본편에서는 동물의 전염성 해면형 뇌증에 대하여 종합적으로 고찰해 보고자 한다.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.9 no.10
• /
• pp.1071-1078
• /
• 2014

Recently, information providing service using Big Data is being expanded. Big Data processing technology is actively being academic research to an important issue in the IT industry. In this paper, we analyze a skilled pattern of welder through Big Data analysis or extraction of welding based on R programming. We are going to reduce cost on welding work including weld quality, weld operation time by providing analyzed results non-skilled welder. Welding has a problem that should be invested long time to be a skilled welder. For solving these issues, we apply connection rules algorithms and regression method to much pattern variable for welding pattern analysis of skilled welder. We analyze a pattern of skilled welder according to variable of analyzed rules by analyzing top N rules. In this paper, we confirmed the pattern structure of power consumption rate and wire consumption length through experimental results of analyzed welding pattern analysis.

• Journal of Advanced Navigation Technology
• /
• v.20 no.4
• /
• pp.292-297
• /
• 2016

Since continuous descent operations (CDO) is one of several tools available to aircraft operators and air navigation service providers (ANSPs) to increase safety, flight predictability, and airspace capacity while reducing noise, controller-pilot communications, fuel burn and emissions, widespread implementation of CDO would result in significant reductions in the environmental impact and aircraft operation costs in south korea as well. After analyzing each procedure from standard terminal arrival routes used for the Incheon international airport, it can be noticed that one of the procedures has a relatively high altitude constraint at initial approach fix than others, which lead the pilots to use unnecessary drag device in certain situations. Therefore we came to a conclusion that some arrival procedures need to be revised, so unnecessary procedure required during approach can be minimized, thereby reducing fuel consumption, noise and emissions compared to current approach procedures. And it is going to increase the safety margin significantly during approach phase due to reduced workload.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.37 no.2
• /
• pp.37-42
• /
• 2000

In this paper, The high-speed, low-Power analog-to-digital conversion structure is proposed using the pipelined comparator away for high-speed conversion rate and the successive- approximation structure for low-power consumption. This structure is the successive-approximation structure using pipelined comparator array to change the reference voltage during the holding time. An 8-bit 10MS/s analog-to-digital converter is designed using 0.8${\mu}{\textrm}{m}$ CMOS technology. The INL/DNL errors are $\pm$0.5/$\pm$1, respectively. The SNR is 41㏈ at a sampling rate of 10MHz with 100KHz sine input signal. The Power consumption is 4.14㎽ at 10MS/s.

• Journal of Navigation and Port Research
• /
• v.44 no.4
• /
• pp.354-361
• /
• 2020

The term "articles for ship" is a general term for all relevant mechanical accessories (SPARE) and consumable materials (STORE) commonly used in ships. Ships commonly are at sea, so it is difficult to respond rapidly to the demand for them in an emergency situation. In particular, it is more difficult to determine the boarding location of tramper ships as it is more difficult to predict the next sailing route in advance. The purpose of this study was to identify the important factors to be considered in determining the boarding location of tramper ships through a survey of each ship owner and ship management company. This valuable information on the proposed supply procedures for each country and port, would be an efficient way to supply articles for ships.

• Journal of Advanced Marine Engineering and Technology
• /
• v.36 no.6
• /
• pp.788-793
• /
• 2012

This study was focused on the estimations of air pollutants, such as PM(Particulate matters), SOx(Sulfur Oxides), $CO_2$(Carbon diOxides) and NOx(Nitrogen Oxides), from a diesel propulsion engine installed on a naval vessel. Legislative and regulatory actions for exhaust emissions from ships are being strengthened in international communities and national governments to protect human health and the environment. In this context, various technologies have been developed from all of the nations of the world to meet strict standards. These regulations are based on commercial ship applications and according to size, but are not suitable for military naval vessels, which have much different engine operating conditions and hull architectures. Additionally, there is no international emission control system for military ships. Emission factors have been updated for commercial ship types from work at various research institutes; however, it is difficult to develop emission factors for military vessels because of their characteristics. In this paper, exhaust emissions from diesel engines installed on naval vessels under steady navigation condition were estimated with emission inventory methodology applied to ocean going vessels using fuel-based methods and fuel sulfur content analysis.