• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 A
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• pp.130-132
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• 1997

In this paper, we propose a new type of tubular linear induction motor(TLIM) with two-dimensional motion. The proposed motor consists of four short primary LIMs arranged on a same circumference and a common secondary. By adopting independently energized ring-windings to the primary, we can expect the reduction of coil-end region and the freedom of alternating current supply. The secondary conductor is capable of producing anyone of rotary, linear, and helical motions by controlling the phase of supply currents in each primary winding. From the 3-D finite element analysis and the experiment, we derive the feeding conditions to increase the subsidiary rotary-force and an optimal arrangement of primary currents to reduce the number of slot.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2005년도 춘계학술대회 논문집
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• pp.97-102
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• 2005

This paper presents feed rate optimizaton of a PMLSM driven feed-slide for mininum vibrations by smoothing velocity curve with finite jerk. First of all, the PMLSM was designed and made to reduce detent force. Next, a PMLSM driven feed-slide system was mathematically modeled as a 4-degree-of-freedom lumped parameter model. The key idea of our vibration minimization method is to find out the most appropriate smooth velocity curve with finite jerk. The validity of our proposed method has been verified by comparing computer simulation results of the feed-slide model with experimental ones.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제54권8호
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• pp.351-357
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• 2005

This paper presents vibration minimization of a PMLSM driven feed-slide by using optimized smooth velocity curve with finite jerk. First of all, the PMLSM was designed and made to reduce detent force. Next, a PMLSM driven feed-slide system was mathematically modeled as a 4-degree-of-freedom lumped parameter model. The key idea of our vibration minimization method is to find out the most appropriate smooth velocity(feedrate) curve with finite jerk. The validity of our proposed method has been verified by comparing computer simulation results of the feed-slide model with experimental ones.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.781-785
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• 2005

Cutting forces and tool deflection in end milling are represented as the closed form of tool rotational angle and cutting conditions. The discrete cutting forces caused by tool entry and exit are continued using the Fourier series expansion. Tool deflection is predicted by direct integration of the distributed loads on cutting edges. Cutting conditions, tool geometry, run-outs and the stiffness of tool clamping pan are considered for cutting forces and tool deflection estimation. Compared to numerical methods, the presented method has advantages in short prediction time and the effects of feeding and run-outs on cutting forces and tool deflection can be analyzed quantitatively. This research can be effectively used in real time machining error estimation and cutting condition selection for error minimization since the ferm accuracy is easily predicted by tool deflect ion curve.

• 한국반도체및디스플레이장비학회:학술대회논문집
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• 한국반도체및디스플레이장비학회 2005년도 추계 학술대회
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• pp.155-159
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• 2005

High speed presses with high resolution in semiconductor lead frame manufacturing process are needed . But high speed operation accompanies mechanical vibration. therefore optimized kinematic structure to minimize vibration is required for a high speed press. And the growing competition in the industry asks a press with low cost, high speed, high resolution, and high pressing force, For this purpose a high speed press was modeled with 3D CAD solid modeling system and dynamic analysis were performed with CAE S/W for multibody dynamic analysis, Through these analyses a motor appropriate to a high speed press was selected and link structure for feeding system of the press was modified to reduce vibration. To perform this analysis working Model which is 2D kinematics and dynamic analysis software was used.

• Journal of Animal Science and Technology
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• 제45권3호
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• pp.455-462
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• 2003

이 연구는 소 비육후기에 칼슘제(석회석)를 첨가하지 않은 사료의 급여가 성장율, 근내지방도 및 혈청 1,25-dihydroxy vitamin $D_3$ ($1,25(OH)_2D_3$) 함량에 미치는 영향을 구명하기 위하여 수행되었다. 거세 한우 24두(20${\sim}$24개월령)를 12두씩 대조구(석회석 2.5% 함유 농후사료)와 칼슘제 무첨가구(석회석 0%)로 배치하여 223일 동안 사료(농후사료 및 오차드그라스 건초)와 물을 무제한 급여하였고, 사양시험이 완료된 후 도축하여 육질을 평가하였다. 혈청 $Ca^{2+}$, Ca 및 P 함량에는 처리 간 차이가 없었으나 (P>0.05), 1,25(OH)2D3 함량은 시험 시작 후 2 또는 6개월째 모두 칼슘제 무첨가구가 대조구보다 (각각 78.3 vs 51.7 또는 80.3 vs 51.1 pg/mL) 높았다 (P<0.01). 칼슘제를 첨가하지 않은 사료를 급여한 비육우가 대조구보다 농후사료 섭취량은 증가하고 건초 섭취량은 감소하는 경향을 보였다. 일당증체량은 대조구보다 칼슘제 무첨가구에서 높았다(P<0.01). 등심단면적(82.8 vs 77.2 $cm^2$), 근내지방도(5.1 vs 2.2) 및 지방 함량(10.2 vs 6.7%)이 칼슘제 무첨가구가 대조구보다 높았고 (P<0.05), 수분 함량(67.6 vs 70.4%)은 낮았다 (P < 0.05). 등심 육색, pH 및 보수력에서는 처리 간 차이가 없었으나 전단력에서는 칼슘제 무첨가구에서 (2.9 vs 3.2 kg/1.27-cm diameter core) 약간 낮게 (P = 0.08) 나타났다. 관능평가에서는 칼슘제 무첨가구가 대조구보다 연도 (4.9 vs 4.5) 및 향미(4.9 vs 4.6)가 약간 개선되었으나 (P<0.05) 다즙성에서는 처리간 차이가 없었다 (P>0.05). 본 연구결과는 비육후기에 칼슘제(석회석)를 첨가하지 않은 사료의 급여는 에너지 섭취의 증가 또는 1,25$(OH)_2D_3$의 합성 촉진을 통하여, 근내지방합성이 증가되어 성장율 및 근내지방도를 개선한다는 것을 제시하였다.

• The Korean Journal of Ecology
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• 제27권6호
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• pp.383-390
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• 2004

본 연구는 1999년 3월부터 2002년 9월에 걸쳐 경기도 시화호, 경기도 웅진군 동${\cdot}$서만도, 장구엽도 3곳에서 검은머리물떼새의 번식기전 행동, 텃세권 행동, 번식생태, 주요 섭식지역과 섭식행동, 종내와 종간번식 및 먹이경쟁에 대해 조사하였다. 검은머리물떼새의 번식 시작은 지역에 따라 차이를 보여 시화호 지역은 4월 중순부터, 동${\cdot}$서만도와 장구엽도의 경우 5월 중순 번식을 시작하였다. 번식에 들어가기 전 짝간의 유대를 강화하기 위한 행동으로 암수짝간의 섭식행동(foraging behavior)과 추적행동(male-female chasing behavior)을 보인다. 교미행동에 들어가기 전 암수는 함께 섭식행동을 하며, 다른 쌍이나 개체들이 섭식장소로 접근해 오면 삑- 삑- 하는 울음소리(piping calling)와 함께 공격적 행동을 보이며 침입자를 쫓아내거나, 침입자 추적비행을 하기도 한다. 연속적 행동양상을 관찰하지 않으면 암수 추적비행과 침입자 추적비행을 구별하기 어렵다. 텃세권 행동은 나비비행(butterfly flight), 음성행동(calling behavior), 침입자 추적행동(chasing behavior), 싸움행동(fight behavior)의 4가지 타입으로 분류하였다. 시화호 지역의 중요 취식 지역은 대부도 선착장 앞쪽, 방어머리 갯벌, 시화방조제 오이도 초입부의 정치망이 설치되어 있는 갯벌, 공단의 조류 조망대 앞쪽 북측 간석지 등 크게 4지역으로 구분된다. 섬지역 중 동${\cdot}$서만도는 썰물시 갯벌에서, 만조시에는 섬 주변에서 취식하였고, 밀${\cdot}$썰물의 차가 없는 장구엽도의 경우 섬 주변에서 주로 취식하였다. 섭식행동 중 종내(intraspecific)와 종간 (interspecific) 경쟁이 이루어졌다. 취식지역에서 검은머리물떼새 개체간에는 먹이를 빼앗기 위해 쫓아가는 행동이 관찰되기도 하고, 중요 취식지역에 다른 개체가 들어올 경우 침입자 추적행동을 하며 쫓아내기도 하였다. 종간 섭식 경쟁은 주로 괭이갈매기와 일어난다. 괭이갈매기와 먹이경쟁이 이루어질 경우에 검은머리물떼새는 먹이를 갈취 당하거나 공격을 받아 다른 지역에서 먹이를 취식하는 개체보다 먹이 섭취율이 상대적으로 떨어지는 것이 관찰되었다. 종간 경쟁이 심하면 섭식지역을 떠나 다른 지역으로 이동하였다.

• Asian-Australasian Journal of Animal Sciences
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• 제20권6호
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• pp.971-975
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• 2007

Two experiments were conducted to evaluate the feeding values of red pepper seed oil meal (RPSOM) and to investigate its dietary supplementation on broiler performances. In Exp. 1, nutritional values of RPSOM were evaluated by analyzing chemical composition and determining true metabolizable energy (TME), nitrogen corrected TME (TMEn) and true available amino acid (TAAA). RPSOM contained 22.50% of CP, 4.75% of ether extract, 27.70% of crude fiber, 4.73% of crude ash and 49.97 ppm of xanthophylls. The contents of capsaicin and dihydrocapsaicin were 34 mg and 31 mg/100 g DM, respectively. The values of TME and TMEn determined by force-feeding 16 roosters were 1.73 kcal/g and 1.63 kcal/g DM, respectively. The average TAAA value of 17 amino acids was 85.22%. In Exp. 2, a total of 225 Ross male broiler chicks, 3 weeks old, were randomly divided into 9 groups of 25 birds each and assigned to three experimental diets containing 0 (control), 5 or 10% RPSOM fed ad libitum for 3 weeks. No significant differences were observed in growth performances and carcass characteristics. The level of serum cholesterol in the 10% RPSOM group was significantly lower than that of the control group (113.92 vs. 137.50 mg/dl). The dietary RPSOM at 5 and 10% levels increased the content of C18:2 ${\omega}{\sigma}$ in leg muscle compared with the control group. The results suggested that RPSOM can be included into broiler feed up to 10% without any negative effects on broiler performances and physiological responses and used as a non-conventional plant protein source, if its nutritional values are well evaluated.

• 한국철도학회논문집
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• 제10권6호
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• pp.650-654
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• 2007

유도전동기는 전기차량의 주요 동력원으로 광범위하게 사용되고 있으며, 유도전동기의 속도제어에 펄스변조 방식을 이용한 인버터의 사용이 증가하고 있다. 본 논문에서는 유도전동기의 인버터 구동시 발생하는 과도전압에 대해 연구하였다. 전원 케이블의 길이에 따른 과도전압의 크기를 측정하였으며, 시간변화율과 운전주파수에 의한 영향을 분석하였다. 실험결과, 케이블의 길이가 길어짐에 따라 과도전압의 최대값이 증가하였으며 50m 케이블에서 과도전압의 크기는 최대 3.3PU까지 측정되었다. 이러한 현상은 진행파의 반사와 투과에 의해 발생하며, 유도전동기의 인버터 구동시 케이블의 길이에 따른 과도전압의 영향을 고려하여 유도전동기의 절연을 설계해야 할 것이다.

• Asian-Australasian Journal of Animal Sciences
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• 제18권4호
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• pp.545-551
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• 2005

A feeding trial was conducted to determine whether dietary vitamin C (200 mg/kg) and vitamin E (250 mg/kg) prevent any drops in egg shell quality under heat stress in broiler breeder hens. One hundred and sixty molted Ross broiler breeders were housed randomly in an individual cage at 83 weeks of age. Four dietary treatments with forty hens and four replications per treatment were control (no additional vitamins), vitamin C-, or vitamin E-supplemented and combined supplementation of the two vitamins. After a tenday-adaptation period at 25$^{\circ}C$, the ambient temperature was kept at 32$^{\circ}C$ for a three-week-testing period. Egg production dropped dramatically over week but it did not show a significant change among treatments (p<0.05). However, egg quality parameters such as egg weight, specific gravity, shell thickness, SWUSA, puncture force and shell breaking strength from the birds fed the diet with the combined vitamins C and E were significantly improved over those of the control group during the heat stress period (p<0.05). The hens fed the vitamin C diet improved tibia breaking strength (37.16 kg), statistically higher than the birds fed the control and the vitamin E diets (p<0.05). The hens fed the control diet showed higher serum corticosterone levels, a mean of 5.97 ng/ml, than those of the other treatments (p<0.05). The heat stress resulted in elevated heterophils and decreased lymphocytes in serum, increasing the H/L ratios for all the treatments. However, the increases in H/L ratios were alleviated by feeding the diets containing vitamin C alone or together with vitamin E, although there were no significant differences in the ratio between the two groups (p<0.05). In conclusion, vitamins C (200 mg/kg) and/or E (250 mg/kg) supplemented to the diets for broiler breeder hens could prevent drops in egg shell quality and tibia bone strength under highly stressful environmental temperatures.