• 한국공작기계학회논문집
• /
• 제10권3호
• /
• pp.75-82
• /
• 2001

The continuous chip in turning operation deteriorates the precision of workpiece and can cause a hazardous condition to operator. Thus the chip form becomes a very important task for reliable turning process. The chip form is identified using the neural network of supervise data Through the measurement of energy radiated from the chip. The feed mechanism os adjusted in order to break continuous chip according to the result of the chip form recognition and it shows a good approach for precision turning operation.

• Journal of information and communication convergence engineering
• /
• 제4권4호
• /
• pp.170-173
• /
• 2006

Recently, with increasing efficiency of DSC (photo-electrochemical using a nano-particle), The Performance of DSC solar generation system also needs improvement. The approach consists of a Fly-back DC-DC (transfer ratio 1:10) converter to boost the DSC cell voltage to 300VDC. The four switch (MOSFET) inverter is employed to produce 220V, 60Hz AC outputs. High performance, easy manufacturability, lower component count., safety and cost are addressed. Protection and diagnostic features form an important part of the design. Another highlight of the proposed design is the control strategy, which allows the inverter to adapt to the: requirements of the load as well as the power source. A unique aspect of the design is the use of the DSP TMS320LF2406 to control the inverter by current and voltage feed-back. Efficient and smooth control of the: power drawn from the DSC Cell is achieved by controlling the front end DC-DC converter in current mode.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2000년도 춘계학술대회 논문집
• /
• pp.890-893
• /
• 2000

In this paper, the test of machinability according to the cutting positions when the ball end milling of hemispheric workpiece is carried out to find the optimum cutting position of free form surface die. Tool runout, cutting force. and chip form are measured. The results show that the optimum cutting condition to get the constant feed per tooth is the inclined angle of 40 degree of workpiece.

• Asian-Australasian Journal of Animal Sciences
• /
• 제13권10호
• /
• pp.1407-1413
• /
• 2000

Oil palm frond (OPF) is a new non-conventional fibrous feed for ruminants. Evaluation on the nutritive values and digestibility of OPF was carried out using goats. In a completely randomised design, 20 local male goats were assigned to evaluate fresh and different types of processed OPF. A 60 day feeding trial was done to determine the digestible nutrient intake of fresh, ensiled and pelleted OPF and its response on live weight gain of goat. The pelleting of OPF increased (p<0.05) intake compared to fresh or ensiled OPF. The OPF based mixed pellet (50% OPF with 15% palm kernel cake, 6% rice bran, 6% soybean hull, 15% molasses, 2% fishmeal, 4% urea, 1.5% mineral mixture and 0.5% common salt) increased (p<0.05) nutrient intake, digestibility and reduced feed refusals. The mixed pellet also increased digestible dry matter intake (DDMI) and digestible organic matter intake (DOMI) at 80% and 63% level respectively than the fresh OPF. The increased digestible nutrient intake on the OPF based mixed pellet, resulted in increased live weight gain of goats. Furthermore, OPF has a good potential as a roughage source when it is used with concentrate supplement. OPF based formulated feed in a pelleted form could be used as a complete feed for intensive production of goat and other ruminants.

• Journal of Advanced Research in Ocean Engineering
• /
• 제2권3호
• /
• pp.136-149
• /
• 2016

Green water impact occurs frequently on offshore platform due to waves with a height greater relative to the freeboard of the structure. This phenomenon exerts a large impact load on the deck. In this paper, offshore platform models with green water protectors of various shapes were fixed to the center of a 3D wave tank to measure the impact pressure acting on the various points on deck and protectors. The impact pressure distribution differed depending on the protector shape, and various patterns of wave creeping up the protector were observed. The protector shape that exerted the lowest pressure impact on the deck will be useful in the deck design of offshore platform, and the model test results will be expected to be used for designers to select the best protector form.

• Asian-Australasian Journal of Animal Sciences
• /
• 제12권6호
• /
• pp.944-950
• /
• 1999

Hexavalent chromium (CrVI) was fed to one day old chicks of Gallus domesticus in the form of different concentrations (250 and 500 mg/kg feed) of potassium dichromate mixed with the feed, ad libitum, for 32 weeks. After 20 weeks of feeding, the total body weight was higher in the low dose (260 mg/kg (feed) group and lower in the high dose (500 mg/kg feed) group, as compared with the control chicks. After 32 weeks of feeding, however, the total body weight was significantly decreased in both the treated groups. Egg laying was enhanced. Fertility remained unaffected, whereas hatchability was considerably decreased after CrVI-treatment. The egg shell thickness increased significantly (13%). Cr was deposited in a dose dependent manner in the liver and lungs. Some structural derangements in liver were also noted in treated chicks. The results of this study i.e., rapid ageing, excessive Cr deposition, decreased hatchability and hepatotoxicity indicate toxic effects of CrVI.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2002년도 춘계학술대회논문집
• /
• pp.991-995
• /
• 2002

차량 실내에서 발생하는 엔진 부밍 소음은 엔진의 진동이 샤시로 전달되어 구조 진동의 형태로 발생하는 구조소음이다. 본 연구에서는 이러한 엔진 부밍 소음과 그 원인이 되는 엔진 진동 사이의 관계를 알아보고자 엔진 마운트 중 한 위치에서 차체로 전달되는 엔진 진동을 줄일 경우 실내 엔진 부밍 소음의 변화를 고찰하였다. 이를 위하여 제어용 구동기를 제작하고 feed-forward 와 feed-back 제어기를 혼합한 hybrid 제어기를 적용하여 실차 실험을 수행하였다.

• Journal of Power Electronics
• /
• 제4권4호
• /
• pp.217-227
• /
• 2004

A robust controller that combines the merits of the feed-back, feed-forward and model-following control for induction motor drives utilizing field orientation control is designed in this paper. The proposed controller is a two-degrees-of­freedom (2DOF) integral plus proportional & rate feedback (I-PD) speed controller combined with a model-following (2DOF I-PD MFC) speed controller. A systematic mathematical procedure is derived to find the parameters of the 2DOF I-PD MFC speed controller according to certain specifications for the drive system. Initially, we start with the I-PD feed­back controller design, then we add the feed-forward controller. These two controllers combine to form the 2DOF I-PD speed controller. To realize high dynamic performance for disturbance rejection and set point tracking characterisitics, a MFC controller is designed and added to the 2DOF I-PD controller. This combination is called a 2DOF I-PD MFC speed controller. We then study the effect of the 2DOF I-PD MFC speed controller on the performance of the drive system under different operating conditions. A computer simulation is also run to demonstrate the effectiveness of the proposed controller. The results verify that the proposed 2DOF I-PD MFC controller is more accurate and more reliable in the presence of load disturbance and motor parameter variations than a 2DOF I-PD controller without a MFC. Also, the proposed controller grants rapid and accurate responses to the reference model, regardless of whether a load disturbance is imposed or the induction machine parameters vary.

• Fisheries and Aquatic Sciences
• /
• 제18권4호
• /
• pp.367-372
• /
• 2015

We investigated the effects of dietary supplementation of two types (powder or liquid) of propolis on innate immunity and disease resistance of olive flounder Paralichthys olivaceus against Edwerdsiella tarda. A total of 600 fish averaging 30 g were randomly distributed into 24 tanks in groups of 25. Three tanks were assigned to each of eight experimental diets: 0 (Control), 0.25, 0.5, 0.75 and 1 % propolis in powder form and 0.25, 0.5 and 1 % propolis in liquid form (PP0.25, PP0.5, PP0.75, PP1, LP0.25, LP0.5 and LP1, respectively). Fish were fed each experimental diet twice daily for four weeks to apparent satiation. At the end of the feeding trial, lysozyme and myeloperoxidase activities and total immunoglobulin level were significantly higher in fish fed the PP1 and LP0.5 diets compared to those fed the control diet. The PP1 diet was also associated with a significant increase in anti-protease activity compared to the control diet. After challenge with E. tarda, fish fed the LP0.5 diet showed numerically higher survival compared to the other groups. This study indicates that non-specific immune responses of olive flounder can be enhanced by dietary supplementation with powder and liquid forms of propolis, and that the optimal level would be 1% in powder form or 0.5% in liquid form. It seemed that growth performance and feed utilization are not affected by the propolis supplementation in diets for olive flounder.

• Asian-Australasian Journal of Animal Sciences
• /
• 제25권8호
• /
• pp.1138-1144
• /
• 2012

This study was conducted to evaluate the efficacy of the dipeptide form of phenylalanine as a new source of amino acid in terms of growth performance and whole-body amino acid composition in comparison to the free form for red seabream (Pagrus major). Fish ($1.46{\pm}0.001g$) were fed four isonitrogenous and isocaloric experimental diets containing 0.7 or 1.4% phenylalanine either in free or dipeptide form. A feeding trial was carried out in three replicates and the fish were fed to apparent satiation for six weeks. At the end of the feeding trial, feed intake of fish was influenced by both phenylalanine form and level and significantly higher values were obtained at an inclusion level of 0.7% and by the use of dipeptide form. However, the other growth parameters did not significantly differ among treatments. Whole-body amino acid compositions revealed no significant changes in concentrations of both essential and non-essential amino acids regardless of the increase in phenylalanine levels or the use of its different forms. The finding in this study indicates that juvenile red seabream can utilize dipeptide phenylalanine as efficiently as free form without any undesirable effects on growth performance or whole-body amino acid composition.