In the car speaker, because the sound characteristics is changed by the space of car which mount the speaker, the speaker elements must be decide according to sound field. In this study, the nonlinear characteristics, the frequency response and the sound pressure for the same size speakers which is adapted to domestic car model are investigated. The car model is classified to semi-midsize, midsized, full size automobile in order to change the car space. As a results, we can investigate the differences of the force factor and the stiffness of suspension system for speaker. According to the change of the speaker characteristics, the sound pressure is changed, also. In the future, these data will be used to investigate the correlation between the sound quality and measurement data.

Recently, as the quality of life of modern people improves, interest in environmental noise is gradually increasing. As the public's awareness of environmental rights increased, it was necessary to grasp the actual condition of the noise source and systematic noise management plan. The data is expected to be used as a response to noise-related complaints. As a result measured using the factory noise monitoring system, the amount of data measured every 5 minutes from 00:00 to 24:00 can obtain 288 noise levels and frequency characteristics per day, and frequency using 1/3 octave-band. The analysis reveals what frequency range affects the noise from the metal working plant near the office. In addition, it can be seen that it is possible to compare with the reference value by using the stored data divided into night time, day time, and evening time for each time zone, and it is determined that it is possible to secure smooth data about the noise source to be measured.

Although most of the automobile bodies are made of steel, the application of aluminum alloy sheet with high strength is under consideration for the development of environmentally friendly lightweight body for fuel economy improvement and carbon dioxide emission reduction. In the case of some inner plates, application of magnesium alloy sheet is examined. TRB plate has been studied mainly for weight reduction and rigidity reinforcement of steel plate parts. Recently, research on aluminum TRB rolled plate for light and environment friendly automobile application has been started, It is expected that the development of eco - friendly TRB rolling material made of light alloy will increase as the importance of light weight body for future energy efficiency increases. Therefore, in this study, we tried to obtain the technology to improve the quality of the product by pre - verifying the cooling performance of the hot forming process through the heat flow analysis and evaluating the cooling performance through the temperature distribution analysis. As a result, it was found that the temperature distribution through the flow velocity problem and the flow of the cooling channel can influence the quality of the final product through different heat distribution and cooling time depending on the shape of the mold and the product.

경기도버섯연구회는 1992년 버섯연구소가 설립되면서 도내 거주하며 버섯을 생산하는 농업인을 대상으로 회원을 모집하여 1993년 7월 29일 창립하였다. 연시총회, 지역순회간담회, 재배법 개선에 관한 세미나, 해 외버섯현황과 전망 등 국내외의 버섯산업 발전을 위한 사업을 지금까지 지속되고 있다. 2000년대 들어서면서 병버섯 증수 배지개발과 기계화가 진행되면서 병재배기술에 관심과 농가의 증가로, 병재배 농가 견학, 일 본의 새로운버섯 재배기술 연수를 하였으며, 학습과 친목단체의 성격이 강한 ‘연구회’에서 수익 사업을 더불 어 추진하는 ‘영농조합법인’ 으로 171명 회원으로 다시 태어났다. 20년 가까이 연구소와 같이 학습단체 및 같은 일을 하는 동호회로 정보교류와 친목도모의 기회를 마련하였지만, 회원이 120명으로 초기의 반으로 감소 하는 실정이다. 이러한 현상은 버섯 뿐만아니라 다른 농업분야에서도 적용되는 것으로 점차 심해지는 경쟁사 회와 정보를 얻는 통로의 다양화에 영향을 받을 수 밖에 없는 현실로 받아들여야 할 것이다. 연구회원구성은 16개 지역으로 경기도 31개 시군의 50%를 차지하며, 전체 회원 중 여주, 양평이 50%를 차지하여, 버섯 주재 배단지로 자리잡고 있다. 최근에는 표고농가 회원이 증가하여 회원의 재배품목이 느타리위주에서 표고버섯 비중이 높아지는 추세이다. 버섯산업이 갈수록 어려워지는 추세에서 버섯인이 살아남기 위해서는 현재 문제 점으로는 버섯품목 및 회원 편중화가 심한 것이다. 이를 해결하기 위해서는 귀농귀촌 신규재배자를 회원으로 확보하거나, 연구회 행사 등 각종 행사를 최소화 하거나, 실제적 참여 회원 위주로 운영하는 것이다. 그렇게 된다면 행사에 소요되는 예산이나 시간이 줄어들것이고, 작은모임이 오히려 서로 친목을 도모하는데는 도움이 될 것이다. 또한, 의무자조금을 조성 등을 통하여 버섯연구회 중심으로 이익사업을 제안하고 추진하면서 회원에게 도움이 된다면 적극적인 연구회 사업에 참여를 유도할 수 있을 것이다. 또한, 버섯연구기관의 실증 시험 추진, 전문가 초청세미나 등을 통해 지속적으로 학습하는 모임으로 유지하는 것도 중요하다. 앞으로, 같은 품목에 종사하는 더불어 잘사는 농업을 추구하고 실용화에 중점을 둔 연구사업과 유용한 정보를 교류하는 기회를 마련하는데 매진해야한다. 또한, 회회원들의 자발적 참여로 유지되고, 회원수감소를 이겨낼 수 있 는 방안마련과 추진으로 진정한 연구회 존속이 바람직하다.

To investigate the cyclic characteristics of the retrofitted exterior joints of RC frame with haunch, 70% scaled 6 beam-column exterior joint subassemblies were designed according to design guideline according to 1988 and tested with cyclic loading up to 3.5% story drift ratio. During the experiments axial forces are applied to columns to simulate gravity load. Experimental results shows that the strength of retrofitted specimens was increased steadily until 2.5% story drift ratio and their strengths increased more than 1.7 times of the non-retrofitted in case that main bar was bent away from exterior joint. The joint strength and effective stiffness of the retrofitted specimen was increased and results in more deformation capacity compared to the non-retrofitted.

Optimizing energy usage for maximum efficiency is an essential goal for manufacturing plants in every industrial manufacturing sector. The generation and distribution of purifying compressed air is a large expense incurred in practically all manufacturing processes. Not only is the generation and treatment expensive equipment of compressed air, but frequent maintenance and effective operation is also required. As a plant’s compressed air system is often an integral part of the production process, it needs to be reliable, efficient, and easy to be maintain. In this paper, we study to find operating method to save energy from the adsorption dryer in the process of purifying compressed air, which is required for a clean room production site in “A” company. The compressed air passes through a pressure vessel with two “towers” filled with a material such as activated alumina, silica gel, molecular sieve or other desiccant material. This desiccant material attracts the water from the compressed air via adsorption. As the water clings to the desiccant, the desiccant particle becomes saturated. Therefore, Adsorption dryer is an extremely significant facility which removes the moisture in the air 70℃ below the dew point temperature while using a lot of energy. Also, the energy consumption of the adsorption dryer can be varied by various operating conditions (time, pressure, temperature, etc). Therefore, based on existing operating experiments, we have searched operating condition to maximize energy saving by changing operating conditions of the facility. However, due to a short experiment period (from September to October), further research will be focused on considering seasonality.

The object of this paper is to evaluate a working environment noise at manufacturing process of metal material products. To accomplish the object; An employee noise exposure criteria, which is mounted in big size enterprise, was investigated. The noise at the 460 points of the manufacturing process machine in the 38 processes of the 1 factories were measured. The database of the noise was built from the measurement data. The major sound sources and frequency range for the manufacturing process of metal material product machine was investigated. In this study, we compare working environment noise criteria of korean with employee noise exposure criteria

Among many potential problems associated with automobiles, the problem regarded as most sensitive and important to the customers is the automobile’s quietness. In particular, because the trend toward the high-performance automobiles is increasing, the quietness should be considered reflecting the increasing demand of the customers for the comfort of automobile ride. Road noise is the low-frequency range in the region of 20Hz to 350Hz, generated when the tires are making contacts with the rough road surface while the automobile is running, in which the noises are resonating within the passenger compartment or with the automobile suspension. In this research, among the factors related to the road noise, the influencing factors associated with the suspension and the tire design were investigated. In particular, among the tire design factors, the structure and the rubber material were investigated as the influencing factors, and for the investigative purpose, experimental tires were manufactured and road noise evaluations were conducted thorough actual feeling tests. Then the test results and correlations were analyzed using the 6-Sigma statistical method. Results from this study shows that, among the tire design factors, the apex is the most influencing factor, in which the height of the apex is the key. The influential factors were found out to be apex height, belt angle, and tread hardness, in that order, and when the suspension is of a same kind, the tendency of the road noise was found to be similar.

The object of this paper is to examine the noise generating mechanism at manufacturing process of metal material products. To accomplish the object; A noise generating mechanism of high noise machine, which is mounted in the small and medium size enterprise, was investigated. The measurement method of the noise for the machine by manufacturers were investigated. The noise at the 250 points of the manufacturing process machine in the 40 processes of the 3 factories, 3 business fields was measured. The database of the noise was built from the measurement data. The major sound sources and frequency range for the manufacturing process of metal material product machine was investigated.

본 연구에서는 내력벽 시스템에 대하여 연결보의 단부에 적용이 가능한 박판형 금속감쇠기의 성능을 실험을 통하여 규명하고자 하였다. 박판형 금속감쇠기의 박판 두께와 길이를 변수로 하여 5개 시험체를 제작하였으며, 층간변위비 5%까지 반복하여 횡력을가력하였다. 실험결과, 금속 박판에 좌굴발생 후 소성변형이 발생하면서 에너지 발산이 이루어졌으며, 기존의 일반 콘크리트 시험체보다에너지 발산량이 크게 나타났다. 박판의 길이가 짧을수록 전단내력의 값은 증가하였으나 발산에너지의 양의 증가는 크게 나타나지 않았다. 실험 내력을 탄성좌굴해석과 비교한 결과, 해석에 의한 내력은 내력곡선 선형영역의 최대값을 적절히 예측함을 알 수 있었다.