This study was conducted to determine whether the layout of wheelhouse and work environment of coastal improved stow net fishing boats affect the physical abnormalities of wheelhouse workers through a survey and to use it as basic data to improve the wheelhouse work environment. The analysis results are as follows. The result of factor analysis on the wheelhouse work environment was classified into three factors: suitability of work environment, suitability of work space arrangement, and layout of navigational and fishing equipment. The result of factor analysis on physical abnormalities was divided into two factors: physical pain and fatigue. The results of regression model analysis showing factors affecting physical pain showed that the t-value in the regression model was 3.625 (p < 0.05), indicating that the work environment suitability had an effect on the physical pain. Work environment suitability had a significantly positive effect on the physical pain. As work environment suitability increased by 1, the physical pain increased by 0.371 (p < 0.05). The results of regression model analysis showing the influencing factors on fatigue were found to have a t-value of 3.009 (p < 0.05) in the regression model, indicating that the work environment suitability had a significantly positive effect on the feeling of fatigue. It was found that fatigue increased by 0.324 (p < 0.05) as the work environment suitability increased by 1. In addition, the manageability of task suitability was found to be t = –2.521 (p > 0.05). As the manageability of task suitability increased, the skipper’s fatigue level decreased. From these results, it is inferred that the wheelhouse of the current coastal improved stow net fishing boats causes physical pain and fatigue for the skippers. In order to reduce such physical pain and fatigue, and to improve safe fishing operation and job satisfaction, it is necessary to provide a wheelhouse to fishermen on coastal improved stow net fishing boats in consideration of the characteristics of the wheelhouse work of fishing boats and in consideration of users.

After the manual shutdown of the Wolseong nuclear power plant due to an earthquake in Gyeongju in 2016, anxiety about the earthquake safety of nuclear power plants has become a major social issue. The shear wall structure used as a major structural element in nuclear power plants is widely used as a major structural member because of its high resistance to horizontal loads such as earthquakes. However, due to the complexity of the structure, it is challenging to predict the dynamic characteristics of the structure. In this study, a three-story shear wall structure is fabricated, and the in-structure response characteristics of the shear wall structure are evaluated through shaking table tests. The test is performed using the Gyeongju earthquake that occurred in 2016, and the response characteristics due to the domestic earthquake are evaluated.

본 연구는 고등학생의 자아존중감, 분노표현, SNS중독경향성의 정도 및 그들 변수 간의 관계와 SNS중독경향성에 미치는 영향 요인을 알아보고자 하는 서술적 조사연구이다. 대상자는 2020년 5월 18일~28일까지 총 10일 간 S시, G도 고등학교에 재학 중이며 SNS을 이용하고 있는 대상자에게 온라인 설문지를 이용하여 총 100부의 자료를 수집하였다. 연구결과, SNS중독경향성과 자아존중감(r=-.385, p<.001), 분노조절(r=-.354, p<.001)과는 보통의 역 상관관계, 분노표출(r=.321, p=.001), 분노억압(r=.308, p=.002)과는 보통의 순 상관관계를 나타냈다. SNS중독경향성에 미치는 영향 요인은 자아존중감(β =-.297, p=.001), 성별(β=.266, p=.003), 분노표출(β=.247, p=.007) 순으로 회귀모형의 설명력은 27.7% 로 나타났다(F=12.279, p<.001). 따라서 SNS중독경향성을 낮추기 위해 고등학생의 자아존중감을 높이고 분노표출을 낮추기 위한 프로그램 개발이 필요하며 특히 성별에서 여자 고등학생의 SNS중독경향성을 낮추기 위한 방안이 모색되어야 할 것이다.

국내 고농도의 초미세먼지 발생 빈도 증가와 함께 그 전구물질인 NH3와 관련한 연구가 활발히 진행 중이다. NH3 배출에 있어 농업의 기여율이 높은 것은 자명한 사실이다. 그러나 비료 사용이 농경지 대기 중 NH3 농도에 장기간 미치는 영향에 관련한 연구는 미비한 실정이다. 따라서 본 연구에서는 수동식 NH3 확산형 포집기를 활용해 11개월 간 농경지 대기 중 NH3 농도를 관측하였다. 그 결과 비료 살포 직후 한 달 동안 NH3 배출의 영향이 가장 큰 것으로 나타났다. 그 이후 여름철 기온 상승으로 NH3 휘발이 촉진되어 대기 중 농도가 증가할 것으로 예상하였으나, 54일간의 지속적인 강우로 인하여 대기 중 높은 암모니아 농도는 관측되지 않았다. 그 후 NH3 농도는 가을과 겨울을 거치면서 점차 감소하였다. 비료의 영향력이 감쇠한 시점 이후에는 기온이 감소할수록, 그리고 강수량이 증가할수록 NH3 농도는 감소하는 것을 상관분석을 통해 확인할 수 있었다. 종합해 보면, 국내 NH3 배출량에서 비료의 기여율을 연구하는 데 있어 비료 살포 직후 최소 한 달 동안은 집중적으로 살펴보아야 할 것이며, 현장 연구 시 강수량과 무강우 일수 등의 기상 정보도 함께 고려해야 할 것이다.

느타리 품종구분을 위한 마커의 개발을 위하여 곤지7호 의 어버이 일핵 균사중의 하나인 MT07156-97의 전체 유전자 염기서열을 바탕으로 제작한 251개의 SSR 프라이머를 제작하였다. 우선적으로 수한1호, 곤지7호, 흑타리 품종에 다형성 여부를 관찰하여 20개의 SSR을 선발하고, 이를 10개 품종에 적용하였다. 단일의 프라이머로는 일부 품종이 구분되지 않았으므로, 선발된 프라이머 간의 다양한 조합(multiplex 방식)을 적용한 결과 모든 품종을 판별 할 수 있는 분자마커 다형성을 보인 프라이머 "166+115" 조합을 선발하였다. 별도로 프라이머 115와 166가 만들어 낸 산술적인 유전자좌(loci) 31개보다 12개 많은 40개의 유전자좌가 증폭되어 다양한 품종에 특이적인 분자마커를 제공할 수 있었다. 개발된 분자마커는 종균의 품질관리, 품종의 판별, 신품종 보호에 활용될 수 있을 것이다.

근대 영어와 영문학에 기여한 대표적인 요인으로 교육혁명과 윌리엄 틴데일의 성경 번역을 들 수 있다. 인본주의와 실용성에 근거한 에라스뮈스의 수사학 이론과 번역된 고전들은 많은 영국 작가들을 위한 토양이 되었다. 이와 같은 환 경에서 교육받은 틴데일은 성경은 모국어로 읽어야 한다는 신학적 동기를 가지고 그의 역서에서 원어의 성경적 의미는 놓치지 않으면서 간결하고도 웅장한 구사를 할 수 있었다. 틴데일 성경에 사용된 다양한 새로운 단어들, 관용구들, 그리고 수사적 장치들은 16세기의 언어적이고 문학적인 발전에 지대한 영향을 미쳤다. 틴데일이 없었다면 엘리자베스 시대와 그 이후에 나타난 직설적인 산문체는 물론이고, 셰익스피어를 비롯한 당대 영국 작가들의 역동적이면서도 간결한 문어체도 없었을 것이다.

The noise environment was evaluated using the ISO recommended NR evaluation curve and PSIL (Preferred Sound Interference Level) in order to investigate the onboard educational environment according to the noise in the Motor Vessel Saehaerim, a fishing training ship under making way. As a result, NRNs were measured at 37-61 dB in accommodation areas, 44-56 dB in work areas, 37-57 dB in educational and conference areas, 83-103 dB in engine areas and 65.3 dB and 51.2 dB in the work and education areas respectively based on PSIL. The NRNs, which evaluated the cabin of the experimental ship according to the purpose, exceeded all of the indoor standard noise recommended by the ISO, and the PSIL had a generally short conversational distance within 0.25-2.3 m and 0.75-1.3 m for teaching and work areas.

In order to collect basic data for the improvement of fishing systems in coastal improved stow net fishery, a questionnaire survey and on-site hearing were conducted from May 10 to June 11, 2019 on the basic items of coastal improved stow net fishery and safety accidents that occurred during fishing operation. The questionnaire for the survey on the actual conditions of coastal improved stow net fishery consisted of a survey on basic matters (six questions) and a questionnaire (six questions) on safety accidents occurring during fishing operation. The results of the survey on basic items were analyzed by region (Incheon, Seocheon, Gunsan and Mokpo), by the captain’s age (less than 50 years of age, 50 to 60 years and more than 60 years of age), by the captain’s career (less than 20 years, 20 to 30 years, 30 to 40 years and more than 40 years) and by the age of fishing vessel (less than 10 years, 10 to 20 years and more than 20 years). According to the survey on basic items of coastal improved stow net fishery such as the captain’s age, the captain’s career, the age of fishing vessel, the fishing nets in use, the crews on board and the operation days per voyage by region, the average captain’s age was 55.7 years, the average captain’s career was 20.5 years, the average age of fishing vessels was 9.0 years, the average numbers of nets used by fishing boats was 14.0 sets, the average numbers of crew on board a fishing boat was 4.4 persons and the average numbers of operation days per voyage was 4.9 days (p < 0.05). As a result of the survey on safety factors during fishing operations, such as experience of ship accidents, major causes of ship accidents experienced, causes of ship accidents (first priority), experience of human accidents, major causes of human accidents, and causes of human accidents (first priority), more than 96% of the respondents experienced ship accidents including collisions with other vessels or fishing gear during fishing operations. The most significant cause of the accident was the other’s fishing gear installed in the fishing grounds. The first possible causes of ship accidents during fishing operations were found to be other fishing gear installed in fishing grounds, steering or engine failure, and inability to avoid accidents during casting and hauling nets. The survey of the experience of human accidents, such as injuries or sea falls, showed that more than 90% of the respondents experienced human accidents during fishing operations. The most important cause of accidents experienced during fishing operations was stucked in a fishing gear during casting and hauling nets. The first important causes of accidents during fishing operations were movement of the fishing gear during casting and hauling nets, damage of the fishing gear such as rope cutting. The results are expected to be provided as a basic data to prevent safety accidents occurring during fishing operation and improve the fishing system in the coastal improved stow net fishery.

철도소음은 도시지역의 철도건설과 유지에 가장 큰 장애 요소 중 하나이므로 보다 효과적으로 철도소음을 저감하기 위한 연구가 활발히 진행되고 있다. 방음터널은 철도소음을 저감할 수 있는 가장 효과적인 방법 중 하나이나, 하절기 높은 내부 온도 증가로 인하여 궤도좌굴 또는 전력, 신호 등 선로 설비의 안정성을 저하시킬 우려가 있다. 이러한 온도 상승 문제는 통기 형 방음판을 이용하여 해결할 수 있으나, 방음터널 적용 시의 소음저감 성능에 대한 연구는 미흡한 상황이다. 이 논문에서는 수치해석을 통하여 통기형 슬릿방음판의 효과적인 방음터널 적용 방법에 대한 연구 결과를 제시하였다. 수치해석은 음향해석 프로그램인 Pachyderm Acoustics으로 모델링한 복선 방음터널을 이용하여 수행하였다. 철도소음은 기존 연구결과를 이용하여 모사하였으며, 슬릿방음판의 적용 위치가 다른 6가지 경우에 대하여 소음저감 효과 변화를 검토하였다. 음향해석 결과 20% 정도 의 슬릿방음판 적용 시에도 철도소음을 최소 5dB 감소할 수 있는 것으로 나타났다.

Martensitic stainless steel is commonly used in the medical implant instrument. The alloy has drawbacks in terms of strength and wear properties when applied to instruments with sharp parts. 440C STS alloy, with improved durability, is an alternative to replace 420 J2 STS. In the present study, the carbide precipitation, and mechanical and corrosion properties of STS 440C alloy are studied as a function of different heat treatments. The STS 440C alloy is first austenitized at different temperatures; this is immediately followed by oil quenching and sub-zero treatment. After sub-zero treatment, the alloy is tempered at low temperatures. The microstructures of the heat treated STS 440C alloy consist of martensite and retained austenite and carbides. Using EDX and SADP with a TEM, the precipitated carbides are identified as a Cr23C6 carbide with a size of 1 to 2 μm. The hardness of STS 440C alloy is improved by austenitization at 1,100 oC with sub-zero treatment and tempering at 200 oC. The values of Ecorr and Icorr for STS 440C increase with austenitization temperature. Results can be explained by the dissolution of Cr-carbide and the increase in the retained austenite. Sub-zero treatment followed by tempering shows a little difference in the properties of potentiodynamic polarizations.

This study analyzes the internal temperature characteristics of heater module using a numerical method when the constant heat flux and heat flux time are applied to the surface heating element. The horizontal and vertical dimensions of heater module are 100mm, and the height is 5mm. The heat flux is 10,000W/m2, 15,000W/m2, and 20,000W/m2, and heat flux time is 5 seconds, 10 seconds, 15 seconds, 20 seconds, 30 seconds and 50 seconds, respectively. When the heat flux time was 50 seconds, the temperature of the surface heating element rose to 120.5°C, while the skin epidermis temperature rose 1.7°C. As a result, the surface temperature of the surface heating element increased greatly in the horizontal direction, while it increased low in the depth direction. This is because the heat conduction of the surface heating element is transmitted in the X-Y plane direction, and the thermal conductivity of the pet(polyethylene terephthalate) film and insulation sheet under the surface heating element is very low. when the heat flux at the surface heating element is 20,000W/m2, the skin's epidermal temperature rises up to 0.82℃ compared to 10,000W/m2 and 15,000W/m2.

Industrial wastewater often contains a number of recalcitrant organic contaminants. These contaminants are hardly degradable by biological wastewater treatment processes, which requires a more powerful treatment method based on chemical oxidation. Advanced oxidation technology (AOT) has been extensively studied for the treatment of nonbiodegradable organics in water and wastewater. Among different AOTs developed up to date, ozonation and the Fenton process are the representative technologies that widely used in the field. Based on the traditional ozonation and the Fenton process, several modified processes have been also developed to accelerate the production of reactive radicals. This article reviews the chemistry of ozonation and the Fenton process as well as the cases of application of these two AOTs to industrial wastewater treatment. In addition, research needs to improve the cost efficiency of ozonation and the Fenton process were discussed.