This study was carried out the estimation on consumption patterns and consciousness of domestic forage for improvement of the quality of domestic forage. Although the cultivated area in South Korea of forage has increased significantly compared to the past, the self-sufficiency rate of domestic forage has increased to around 80% since 2010. Also, livestock farmers prefer to use import forage than domestic due to convenience of use. In Korean beef farms, the ratio of import to domestic forage was higher in domestic forage (import forage 3 : domestic forage 7). In the method of securing domestic forage, purchase of forage (55.6%) was higher than self-cultivation of forage (44.4%). The ratio of use by bailing type was shown in the order of rice staw rice straw (50.5%), domestic hay (15%), imported hay (12.5%), and total mixed ratio (10.7%). The preference of forage was in the order of amount of foreign matter, moisture content, price, feed value in Korean native cattle farm. The result of satisfaction with domestic and import forage showed that the satisfaction of domestic forage price was higher than import forage, while the moisture content and foreign matter of forage were lower than import forage. In addition, in the results of the satisfaction and importance of domestic roughage compared to imported roughage, satisfaction with imported roughage was generally high in all items except for price. As a result, in order to improve the satisfaction of domestic forage in Korean native cattle farm, it is necessary to minimize foreign matter in forage and increase hay production for moisture content uniform in forage.

An interference fit is a fastening between two parts which is achieved by friction after the parts are pushed together, rather than by any other means of fastening. A fit is depending on which part has its size controlled to determine the fit. To select an amount of interference see KS standard tables for class from light to heavy drive fits. The aim of this paper is to find the optimal gap under the interference fit with lowest contact pressure to the two cylinders. To accurately determine the amount of interference clearance, must consider the fluctuation of the response parameters such as contact pressure, displacements and stresses. The response of the cylinder system is modelled with the probabilistic finite element method using the Monte Carlo simulation. The probabilistic design is carried out using ANSYS probabilistic design software. And then the optimal design of the interference gap is sequentially solved to find the solution. The practical optimal design is proposed for the design of the interference fit system. The numerical results are obtained where the displacements and stresses treated as constraints.

Structural dynamic system involves random variables conditions such as material property, geometric parameters and applied loads. This uncertainties result from the structural parameter are carefully considered the dynamic structural response in displacement, stress, and natural frequencies. The random vibrational system must be designed to withstand a certain amount of the fluctuation with respect to the uncertainties. Harmonic response of a spring-mass system is mathematically modelled with the probabilistic finite element method using the Monte Carlo simulation. The aim of this paper is to find the optimal lowest frequency for the spring-mass system with random input variables and response parameters to the displacements. The probabilistic design is carried out using ANSYS probabilistic design module in a commercial application software and then the optimal design is sequentially solved. An efficient and practical optimal design evaluation method is proposed for the design of the harmonic system. The numerical results are obtained where the next highest frequency of the system and displacements treated as constraints.

Structural system involves random conditions such as material property, geometric parameters and applied loads. This is caused by either measurement inaccuracy or system complexity and must be designed to withstand the uncertainties, Random structures may be modelled by using the finite element method using Monte Carlo simulation. It can be applied easily to any structural system with random parameters. The aim of this paper is to find the shape optimal design for the cantilever beam with random input variables to the height and response parameters to the displacement and stresses. The probabilistic design is carried out using ANSYS probabilistic design module in a commercial application software and then the optimal design is sequentially solved. An efficient and practical shape optimal design evaluation method is proposed for the design of the cantilever beam shape. The numerical results are obtained where total volume of the beam, stresses and displacements in the beam treated as constraints

본 연구에서는 정제되지 않은 ZnO 및 TiO₂나노입자를 M4배지에 노출시켜 두 나노입자가 어느 정도 크기의 응집체로 변화되는지를 살펴보고 또한 두 나노입자가 수생태계 생물종인 Daphnia magna에 어떠한 영향을 초래하는지 유영저해 및 폐사율을 통해 살펴보았다. ZnO 및 TiO₂나노입자의 분말상태 크기는 각각 20 nm와 40 nm였지만, M4배지에서는 1333 nm와 1628 nm로 약 40~70배의 크기로 응집되었다. 유영저해의 경우 ZnO와 TiO₂나노입자 모두 시간 및 농도가 높아질수록 D.magna가 유영하는데 영향을 미친 것으로 나타났으며, 특히 ZnO나노입자가 TiO₂나노입자에 비해 더 큰 영향을 미치는 것으로 나타났다. 폐사율의 경우 ZnO나노입자에서는 시간 및 농도가 높아질수록 폐사되는 비율이 높았으며, TiO₂나노입자에서는 72시간이 경과된 시점의 10 ppm 이상의 농도에서 폐사하는 것으로 관찰되었다. 이는 나노입자가 해양에 유입됨으로 인해 원래의 크기에 비해 응집되어 증가되어진다는 것을 알 수 있으며, 또한 그 응집체로 인해 수생태계 생물에 영향을 주는 것으로 나타났다.

‘In structural system, a certain amount of uncertainties always persists in material properties, geometric parameters and applied loads. In this study, the structure is designed to withstand the uncertainties which are caused by either measurement inaccuracy or system complexity. Random structures are modelled by using ANSYS probabilistic design module. It can be applied easily to any structural system with random parameters. The aim of this paper is to make optimal design for the beam with random input variables due to width and height and response parameters due to displacements and stresses. The probabilistic design is also carried out with ANSYS APDL and then the optimal design is sequentially solved. As the total volume of beam, stresses and displacements at the beam are treated as random parameters, the numerical results are obtained.'

본 연구결과 조농비가 다른 사료를 각각 급여한 젖소에 서 임신초기의 유방 크기는 HF군이 LF군 보다 2.4배 가량 유의하게 컸으나, 임신중기와 착유기 동안에는 두 군 간에 차이가 없었다. Estradiol의 혈중농도는 두 군 모두 사춘기 부터 서서히 증가하여 임신기간 동안 사춘기의 2~3.5배가 량이 되었으며, 두 군간 유의한 차이는 나타나지 않았다. 착유기 전 기간에 걸쳐서도 estradiol의 농도는 두 군간 차 이가 없었다. Progesterone의 혈중 농도는 사춘기부터 증가 하기 시작하여 임신중기까지 두 군 모두 비슷한 농도로 유지되었으며, 시험 전 기간에 걸쳐 두 군간 유의한 차이는 없었다. 산유량 4% FCM은 두 군 모두 분만 후 증가하다 LF군은 분만 100일, HF군은 150일을 기점으로 감소하였다. 그러나, 분만 후 50일까지를 제외하고 그 후 전 기간에 걸 쳐 양질 조사료 함량이 높은 사료를 급여한 HF군의 젖소 에서 산유량이 유의하게 높았으며, 분만 250일 까지도 높 은 산유량을 유지하였다. 우유 내 체세포 수는 분만초기를 제외하고 착유기 전 기간 동안 HF군에서 유의하게 감소하 였다. 유지율은 분만 후 비유 초기에 LF군에서 다소 높게 나타났으나, 그 이후부터는 두 군간 차이가 없었으며, 그 밖에 우유 내 단백율, 고형율, MUN 모두 두 군간 차이는 관찰되지 않았다. 산유량과 체세포 수 및 유지율을 기초로 계산한 유대에 있어 HF군이 LF군에 비하여 최고 141.5% 증대되었다. 본 연구결과로부터 젖소의 양질 조사료의 함 량을 적당 수준으로 증가시킴으로써 유방의 크기나 관련 호르몬의 변화 없이 우유의 생산량을 증대시키고 우유의 질을 높일 수 있을 것으로 평가되었다.

Belleville springs can sustain relatively large loads with small deflections and belleville spring washers are especially suited for high loads in small places. Belleville springs are used singly or in stacks to achieve desired load such as power transmission components. The aim of this paper is to design for the belleville spring diameter and thickness to minimize volume of the system. The design is carried out using finding solution in a commercial spreadsheet application software, Microsoft Excel 2007. The numerical results are obtained where the displacement, stress and load in the spring are treated as constraints function.

나노입자란 직경 100nm 이하의 크기를 가진 입자로 가전, 기능성 화장품, 반도체, 항균제 및 광촉매제 등에 널리 사용되어 있어 본 연구는 9종류의 나노입자가 참굴 수정란에 미치는 영향을 살펴보았다. 나인입자를 첨가하지 않은 대조구에서는 인공 수정한 참굴 수정란의 78%가 D형 유생으로 발생하였다. 은(Ag)이 2% 함유된 AGZ020, Nano silver 및 P-25의 나노입자와 주석산화물인 SnO의 나노입자는 24시간 경과 후 0.05ppm 농도에서 각 각 22%, 52%, 58% 및 76%가 D형 유생으로 발생하였으나, 20ppm 농도에서 8시간 이내 참굴 수정란을 모두 파괴하였다. In, Sb, Sn, Zn 및 Ag-TiO2의 나노입자는 24시간 경과 후 0.05ppm 농도에서 모두 70%이상의 D형 유생으로 발생하여 상대적으로 낮은 농도에서 큰 영향을 받지 않는 것으로 나타났으나, 20ppm 농도에서 대조에 비해 D형 유생 발생율이 각 각 57%, 60%, 50%, 65% 및 64%로 저해되었다.

A fresh water generator is designed to produce fresh water from sea water. This generator produces fresh water by evaporating and condensing sea water, and it uses the engine jacket water as the heat source. While a vessel is sailing, it uses main engine coolant to produce fresh water and also, while a vessel is in port, it uses auxiliary engine coolant. After all, sea water is evaporated the heat which the coolant contains, so it can produce fresh water economically, because it dose not need additional heat source. A salinity meter is a densitometer measuring the concentration of salt in sea water. This study designed the multi-function salinity meter(SAL-2000). SAL-2000 has many functions such as conductivity, salinity, flow rate, and so on. In order to evaluate the performance of SAL-2000, the measuring experiments such as salinity, flow rate, and pressure have been conducted.

A valve open/close degree measuring device is used for an indicator of a valve actuator. This device indicates an opening and closing of a valve or throttle in a hydraulic actuator. In ship, equipments requires safe and robust because of a rough environment and a specific condition during a voyage. Thus, the open/close degree measuring device must be developed which can be used at an outdoor environment. This study developed the open/close degree measuring device using a volumetric measuring method(25㎖/100㎖). The housing of the open/close degree measuring device was made by a stainless steel with surface painting after an anodizing coating.