• Food Science of Animal Resources
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• v.27 no.3
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• pp.284-289
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• 2007

This study was conducted to investigate the effects of copper and zinc supplementation on growth performance, nutrient digestibility, and meat and carcass characteristics in finishing pigs. A total of 72 $(Landrace{\times}Yorkshire{\times}Duroc)$ pigs (58.47 kg initial BW) were assigned to 6 treatments in a $2{\times}3$ factorial design $(Zn\;levels{\times}Cu\;levels)$. The sources of zinc and copper were Zn-methionine chelate and Cu-methionine chelate, respectively. Zinc levels used were 80 and 120 ppm and copper levels used were 10, 30 and 60 ppm. Throughout the entire experimental period, the average daily gain (ADG) and average daily feed intake (ADFI) were not significantly affected by Cu or Zn levels, or their relative levels. The G:F ratio was significantly affected by the relative levels of Cu and Zn (p<0.05), specifically at 30 ppm Cu and 120 ppm Zn. Dry matter digestibility was significantly affected by the levels of Cu (p<0.02), Zn (p<0.01) and the relative levels of each (p<0.04), in particular at 30 ppm Cu and 120 ppm Zn. Nitrogen digestibility was significantly affected by Zn levels (p<0.01) and the combination of 30 ppm Cu and 120 ppm Zn (p<0.03). The $L^*-value$, shear force, cooking loss and pH were not significantly affected by Cu levels, Zn levels or their combination. The $a^*- (p<0.04)\;and\;b^*- values (p<0.01)$ were significantly affected by Zn levels at 80 ppm. The Water hoding capacity was significantly affected by Cu and Zn in combination (p<0.01) at 10 ppm Cu and 120ppm Zn. The carcass weight, backfat thickness and carcass grade were not significantly affected by Cu levels, Zn levels or their relative levels. The carcass percentage was significantly affected by the combination (p<0.04) of 30ppm Cu and 120ppm Zn. In conclusion, dietary supplementation of Cu and Zn at 30 and 120 ppm, respectively, is effective for feed efficiency, nutrient digestibility and carcass percentage, while at the levels of Cu at 10 ppm and Zn at 120 ppm have effects on WHC.

• The Magazine of the IEIE
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• v.29 no.6
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• pp.76-80
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• 2002

'Liquid Crystal의 상전이(相轉移)와 광학적 이방성(異方性)이 1888년과 1889년 F. Reinitzer와 O. Lehmann에 의해 Monatsch Chem.과 Z.Physikal.Chem.에 각각 보고된 후 부터 제2차 세계대전이 끝난 뒤인 1950년대 까지는 Liquid Crystal을 단지실험실에서의 기초학문 차원의 연구 대상으로만 다루어 왔다. 1963년 Williams가 Liquid Crystal Device로는 최초로 특허 출원을 하였으며, 1968년 RCA사의 Heilmeier등은 Nematic 액정(液晶)에 저주파(低周波) 전압(電壓)을 인가하면 투명한 액정이 혼탁(混濁)상태로 변화하는 '동적산란(動的散亂)'(Dynamic Scattering) 현상을 이용하여 최초의 DSM(Dynamic Scattering Mode) LCD(Liquid Crystal Display)를 발명하였다. 비록 150V 이상의 높은 구동전압과 과소비전력의 특성 때문에 실용화에는 실패하였지만 Guest-Host효과와 Memory효과 등을 발견하였다. 1970년대에 이르러 실온에서 안정되게 사용 가능한 액정물질들이 합성되고(H. Kelker에 의해 MBBA, G. Gray에 의한 Cyano-Biphenyl 액정의 합성), CMOS 트랜지스터의 발명, 투명도전막(ITO), 수은전지등의 주변기술들의 발전으로 인하여 LCD의 상품화가 본격적으로 이루어지게 되었다. 1971년에는 M. Shadt, W. Helfrich, J.L. Fergason등이 TN(Twisted Nematic) LCD를 발명하여 전자 계산기와 손목시계에 응용되었고, 1970년대 말에는 Sharp에서 Dot Matrix형의 휴대형 컴퓨터를 발매하였다. 이러한 단순 구동형의 TN LCD는 그래픽 정보를 표시하는 데에는 품질의 한계가 있어 1979년 영국의 Le Comber에 의해 a-Si TFT(amorphous Silicon Thin Film Transistor) LCD의 연구가 시작되었고, 1983년 T.J. Scheffer, J. Nehring, G. Waters에 의해 STN(Super Twisted Nematic) LCD가 창안되었고, 1980년 N. Clark, S. Lagerwall 및 1983년 K.Yossino에 의해 Ferroelectric LCD가 등장하여 LCD의 정보 표시량 증대에 크게 기여하였다. Color화의 진전은 1972년 A.G. Ficher의 셀 외부에 RGB(Red, Green, Blue) filter를 부착하는 방안과, 1981년 T. Uchida 등에 의한 셀 내부에 RGB filter를 부착하는 방법에 의해 상품화가 되었다. 1985년에는 J.L. Fergason에 의해 Polymer Dispersed LCD가 발명되었고, 1980년대 중반에 이르러 동화상(動畵像) 표시가 가능한 a-Si TFT LCD의 시제품(試製品) 개발이 이루어지고 1990년부터는 본격적인 양산 시대에 접어들게 되었다. 1990년대 초에는 STN LCD의 Color화 및 대형화(大型化) 고(高)품위화에 힘입어 Note-Book PC에 LCD가 본격적으로 적용이 되었고, 1990년대 후반에는TFT LCD의 표시품질 대비 가격경쟁력 확보로 인하여 Note-Book PC 시장을 독점하기에 이르렀다. 이후로는 TFT LCD의 대형화가 중요한 쟁점으로 부각되고 있고, 1995년 삼성전자는 당시 세계최대 크기의 22' TFT LCD를 개발하였다. 또한 LCD의 고정세(高情細)화를 위해 Poly Si TFT LCD의 개발이 이루어졌고, 디지타이져 일체형 LCD의 상품화가 그 응용의 폭을 넓혔으며, LCD의 대형화를 위해 1994년 Canon에 의해 14.8', 21' 등의 FLCD가 개발되었다. 대형화 방안으로 Tiled LCD 기술이 개발되고 있으며, 1995년에 Sharp에 의해 21' 두장의 Panel을 이어 붙인 28' TFT LCD가 전시되었고 1996년에는 21' 4장의 Panel을 이어 붙인 40'급 까지의 개발이 시도 되었으며 현재는 LCD의 특성향상과 생산설비의 성능개선과 안정적인 공정관리기술을 바탕으로 삼성전자에서 단패널 40' TFT LCD가 최근에 개발되었다. Projection용 디스플레이로는 Poly-Si TFT LCD를 이용하여 $25'{\sim}100'$사이의 배면투사형과 전면투사형 까지 개발되어 대형 TV시장을 주도하고 있다. 21세기 디지털방송 시대를 맞아 플라즈마디스플레이패널(PDP) TV, 액정표시장치 (LCD)TV, 강유전성액정(FLCD) TV 등 2005년에 약 1500만대 규모의 거대 시장을 형성할 것으로 예상되는 이른바 '벽걸이TV'로 불리는 차세대 초박형 TV 시장을 선점하기 위하여 세계 가전업계들이 양산에 총력을 기울이고 있다. 벽걸이TV 시장이 본격적으로 형성되더라도 PDP TV와 LCD TV가 직접적으로 시장에서 경쟁을 벌이는 일은 별로 없을 것으로 보인다. 향후 디지털TV 시장이 본격적으로 열리면 40인치 이하의 중대형 시장은 LCD TV가 주도하고 40인치 이상 대화면 시장은 PDP TV가 주도할 것으로 보는 시각이 지배적이기 때문이다. 그러나 이러한 직시형 중대형(重大型)디스플레이는 그 가격이 너무 높아서 현재의 브라운관 TV를 대체(代替)하기에는 시일이 많이 소요될 것으로 추정되고 있다. 그 대안(代案)으로는 비교적 저가격(低價格)이면서도 고품질의 디지털 화상구현이 가능한 고해상도 프로젝션 TV가 유력시되고 있다. 이러한 고해상도 프로젝션 TV용으로 DMD(Digital Micro-mirror Display), Poly-Si TFT LCD와 LCOS(Liquid Crystals on Silicon) 등의 상품화가 진행되고 있다. 인터넷과 정보통신 기술의 발달로 휴대형 디스플레이의 시장이 예상 외로 급성장하고 있으며, 요구되는 디스플레이의 품질도 단순한 문자표시에서 그치지 않고 고해상도의 그래픽 동화상 표시와 칼라 표시 및 3차원 화상표시까지 점차로 그 영역이 넓어지고 있다. <표 1>에서 보여주는 바와 같이 LCD의 시장규모는 적용분야 별로 지속적인 성장이 예상되며, 새로운 응용분야의 시장도 성장성을 어느 정도 예측할 수 있다. 따라서 LCD기술의 연구개발 방향은 크게 두가지로 분류할 수 있으며 첫째로는, 현재 양산되고 있는 LCD 상품의 경쟁력강화를 위하여 원가(原價) 절감(節減)과 표시품질을 향상시키는 것이며 둘째로는, 새로운 타입의 LCD를 개발하여 기존 상품을 대체하거나 새로운 시장을 창출하는 분야로 나눌 수 있다. 이와 같은 관점에서 현재 진행되고 있는 LCD기술개발은 다음과 같이 분류할 수 있다. 1) 원가 절감 2) 특성 향상 3) New Type LCD 개발.

• Journal of Bio-Environment Control
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• v.14 no.3
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• pp.155-159
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• 2005

This study was carried out to investigate the effects of cultivars and to establish the hydroponic cultivation method of spinach (Spinacia oleracea L.) f3r autumn season. Considering the rate of germination, plant height is 25 cm interior and exterior and leaf blade and petiole attitude is erect the best two cultivars 'Artlars', 'Dimple' were selected among the 19 cultivars tested. Seed germination was more than $90{\%}$ in both cultivars of 'Artlars', 'Dimple'. Seed rate of germination drops more or less, but it was cultivar that 'Mahoroba' cultivars is becoming in export standard production, and 'Premium', 'Platon' cultivar which plant height of leaf blade and petiole attitude is erect is about 20 cm was thought by suitable cultivars to domestic. Plant height relationship difference that follow to planting distances decreased according as planting distances growth than $12{\times}11$ cm to $12{\times}15$ cm. In the meantime, the increase of leaf area and fresh weight was increasing transplanting distance. The yield per ha of 14,890 kg in the $12{\times}11$ cm was $67{\%}$ increased than that in the $12{\times}9$ cm. Therefore, $12{\times}11$ cm spacing is considered optimum planting distance for spinach hydroponic cultivation in autumn season.

• Journal of Korean Society of Forest Science
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• v.26 no.1
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• pp.57-65
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• 1975

This study was carried out to examine the effect of manufacturing factors on physical properties of hardboard (S.I.S) made from the juvenile wood of sycamore (Platanus orientalis L.) The results obtained may be summarized as follows: 1. The difference among the yields of pulp treated with preheat time (defibrate condition) was significant in those of treatments. There was no difference in the yield of pulp treated with defibrate time. The yields of pulp on the tree age classes were shown the difference by 2<4<6<8 years. 2. The specific gravities of hardboard that were treated with hot pressing conditions showed us significantly in those of treatments. There was no difference on the specific gravities among hardboards, treated with resin and wax contents. But in all cases of the specific gravities satisfied the standard which specified the KS F 3203 (Hardboard) 3. The moisture contents of hardboard satisfied the standard which calls for 13-percent below. There were difference in moisture contents between hardboard, treated with preheating time, resin and wax contents and hot pressing conditions. And the moisture contents of hardboard on the tree age classes showed the difference by 2<4<6<8 years. 4. The water absorption and thickness swelling of hardboard treated with defibrations, resin and wax contents, and hot pressing conditions were significant in those of treatments. And the water absorption and thickness swelling of hardboard on the tree age classes showed us the significant difference by 8<6<4<2 years. 5. The difference among the flexural strength in using tested three conditions showed us the difference by defibration$200kg/cm^2$) of hardboard, it is likely to be recommened that the juvenile wood of sycamore is valuable for the raw materials of hardboards.

• The Korean Journal of Pesticide Science
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• v.8 no.4
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• pp.299-308
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• 2004

In order to elucidate the behavior of bensulfuron-methyl, a sulfonylurea herbicide, in a soil/plant microecosystem, rice plants (Oryza sativa L.) were grown for 12 weeks in the specially made stainless steel pots (17cm I.D. $\times$ 10cm H.) containing two different paddy soils treated with fresh and 13-week-aged residues of [phenyl-$^{14}C$]bensulfuron-methyl, respectively. During the aging period, the mineralization to $^{14}CO_2$ from soil A (OM, 3.59%; CEC, 7.65 $cmol^+\;kg^{-1}$; texture, sandy clay loam) and B (OM, 1.62%; CEC, 4.51 $cmol^+\;kg^{-1}$; texture, sandy loam) amounted to 6.79 and 10.15% of the originally applied $[^{14}C]$bensulfuron-methyl, respectively. The amounts of $^{14}CO_2$ evolved from the soils with fresh residues were higher than those from the soils with aged residues. At harvest after 12-week growing, $^{14}C$-radioactivity absorbed and translocated into rice plants from soils A and B containing fresh residues of bensulfuron-methyl was 1.53 and 4.40%, while 4.04 and 6.37% in the two soils containing aged residues, respectively. Irrespective of aging and soil type, the $^{14}C$-radioactivity remaining in soil ranged from 80.41 to 98.87% of the originally applied $[^{14}C]$bensulfuron-methyl. The solvent extractability of tile soils was $39.25\sim70.39%$, showing the big differences among the treatments. Most of the nonextractable soil-bound residues of $[^{14}C]$bensulfuron-methyl were incorporated into the fulvic acid fraction$(61.32\sim76.45%)$. Comparing the microbial activity of the soils with rice plants grown with that of the soils without them, the former was $1.6\sim3.0$ times higher than the latter. However, it did not correlate with the $^{14}CO_2$ evolution.

• Childhood Kidney Diseases
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• v.4 no.2
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• pp.136-143
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• 2000

Purpose : The hemolytic uremic syndrome (HUS) is characterized by microangiopathic hemolytic anemia thrombocytopenia, and acute renal failure. It is ole of tile most common cause of acute renal failure in children but few reports are available in Korea. Thus we investigated the 23 patients diagnosed as HUS during last 14 years. Method : We retrospectively investigated the etiologic factor, clinical manifestations laboratory findings, treatment modalities, and final outcomes of the patients. Then patients were divided into two groups according to outcome, md comparison was performed. Group A(8) comprised patients who progressed to end-stage renal disease or expired. Group B(15) comprised patients who completely recovered after dialysis treatment. Result The number of patients aged less than 4 years were 17; between 5 and 10 were 4 and more than 10 were 2. The gende ratio was M:F=2 : 1. The etiologic factors were as follows: acute gastroenteritis in 14 patients including 4 bloody diarrhea, upper respiratory tract infection in 7 patients, and 1 patient with herbal mediation. The overall mortality rate was 22$\%$: 2 patients died of US complications, 2 patients died of sepsis, and 1 patient died of pulmonary hemorrhage. Group A (Hb 4.8${\pm}$1.2 g/dL) showed lower value in hemoglobin than group B (Hb 6.3${\pm}$1.7 g/dL) during hospital stay (P< 0.05), And the time interval between tile disease onset and dialysis treatment was significantly longer in group A ($11.9{\pm}9.1\;days\;vs\;2.8{\pm}2.1\;days$) (P< 0.05). Conclusion : Overall mortality rate was 22$\%$. Low hemoglobin value and the prolonged time interval between the disease onset and dialysis treatment were related with poor prognosis. So early diagnosis and appropriate intensive care including dialysis treatment is essential to achieve better outcome in children.

• Food Science of Animal Resources
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• v.27 no.1
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• pp.53-59
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• 2007

This study was conducted to determine the effects of dietary supplementation with probiotics on the growth and meat quality of finishing pigs. A total of forty eight ($Landrace{\times}Yorkshire{\times}Duroc$) pigs ($55.3{\pm}1.5 kg$ average initial body weight) were randomly assigned to four groups and fed on a diet supplemented with 0, 0.2, 0.5 or 1% probiotics for 58 days. The pigs were slaughtered at approximately 105 kg live weight. Supplementation with 0.2% probiotics significantly (p<0.05) increased daily gain compared to the control. The daily gain of pigs in the 0.2% probiotic group was 0.95 kg whereas that of the control was 0.85 kg. The average feed intake was 2.79-2.84 kg and there were no significant differences in feed intake between the control and test groups. The feed conversion of the 0.2% probiotic group was 2.96 kg whereas the control showed a feed conversion of 3.28 kg. The results of this study imply that supplementation with 0.2% probiotics may improve the feed conversion of pigs. There were significant differences in carcass weight, carcass ratio, backfat thickness, and frequency percentage of A grade carcasses between the control and probiotic test groups. In addition, the moisture, crude protein and crude ash contents of the probiotic treated groups did not differ significantly from the control group, however the crude fat values of the 0.2% probiotic test group was significantly tower than the other groups. The muscle pH levels of all samples ranged from 5.63-5.67 which is the normal pH of pork. The supplementation of probiotics resulted in decreased lightness ($L^*$) values and increased redness ($a^*$) values. Furthermore, the saturated fatty acid contents of the 0.2% and 0.5% probiotic test groups decreased and the unsaturated fatty acid contents increased relative to the control.

• Korean Journal of Environmental Agriculture
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• v.39 no.1
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• pp.36-43
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• 2020

BACKGROUND: Wicheon watershed has the largest irrigation area among the mid-watershed of Nakdong river. However, no investigation of irrigation water quality has been conducted on the Wicheon watershed, which evaluates the effects on the soil quality and crop cultivation. Therefore, this study aims to provide various assessments of water quality of Wicheon watershed as the scientific basic data for efficient agricultural activities. METHODS AND RESULTS: Water sampling was performed in five locations of the first tributaries of Wicheon. Wicheon watershed showed clean water quality with very low organic matters and safe water quality from metals at all points of investigation. It was estimated that the natural chemical components of Wicheon watershed were originated from water-rock interaction in Gibbs diagram. All samples were concentrated in the type of Ca-HCO₃-Cl in the Piper diagram. The quality of irrigation water was evaluated with sodium adsorption ratio (SAR), residual sodium carbonate (RSC), permeability index (PI), and percent sodium (%Na). The values of these water quality indices were in the range of 0.37-0.67, -2.11--0.24, 41.13-84.52% and 11.28-21.84%, respectively, and were classified as good grades at all sites. CONCLUSION: The water quality of Wicheon watershed was very low in salt, indicating good irrigation water suitable for growing agricultural products. We hope that the results of this study will be used as the basic data for the cultivation of agricultural products and promotion of their excellence.

• Korean Journal of Environmental Biology
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• v.17 no.1
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• pp.35-50
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• 1999

The relationship between floristic composition and soil environmental conditions was investigated in the forest vegetation of Mt. Paekun. The forest vegetation unit of Mt. Paekun was divided into six plant communities by Zurich-Montpellier method, such as Quercus mongelica community (Typical subcommunity, Rhododendron schlippenbaohii subcommunity), Q. variabilis community, Fraxinus rhynchophylla community, Pinus densiflora community, Larix Eeptolepis community and Pinus koraiensis community. Q. mongolica community group was distributed at the altitude over 500 meter, Q. variabilis and P. densiflora communities appeared on the southwestern slope at the altitudes of 600 ~ 700 m and 290 ~ 700 m. However, L. leptolepis and P. koraiensis plantation were distributed at lower altitude, on hillside or around homestead. The DBH class distribution of dominant species in each community showed that Q. mongolica had 10.9 individuals/a at 6~10 cm class, Q. variabilis 2.5 individuals/a at 11~15 cm class, P. densiflora 1.8 individuals/a at 26~30 cm class, F. rhynchophylla 3.3 individuals/a at 2~5 cm class, and L. leptolepis 5.9 individuals/a at 11~ 15 cm class. Q. mongolica and Q. variabilis communities showed a stable bell-shaped pattern of distribution. The contents of organic matters and soil water, and cation exchange capacity of the soil increased, and the pH decreased as the altitude gets higher increased altitude at the each communities. The contents of the soil water and organic matters of the forest soil collected in Q. mongolica community were in the 17.81% to 51.20% and 5.51% to 14.90%, respectively. These tendency is similar to the contents of N, P and K, but those of Ca, Mg, and CEC was lower than in other communities. Cation exchange capacity was suspected to be correlated to the pH. The hypothetical successional sere of the forest vegetation of Mt. Paekun is as follows: Pinus densiflora community longrightarrowQ. variabilis community longrightarrowQ. mongolica community.

• Journal of Animal Science and Technology
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• v.48 no.2
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• pp.203-210
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• 2006

This experiment was conducted to determine the Effect of soybean oil, dried palm oil powder and monoglyceride supplementation on growth performance and serum lipid changes in weaned pigs. One hundred twenty five cross-bred pigs((Y×L)×D, 6.00±0.79kg average initial BW) were used in a 21 d growth trial. Dietary treatments included SOY(containing 5% soybean oil), PALM(containing 5.5% dried palm oil powder) and SOPM0, 12.5 and 25(containing 2.5% soybean oil and 2.7% dried palm oil powder containing 0%, 12.5% and 25.0% monoglyceride, respectively). For the whole period, ADFI was increased in dried palm oil powder containing monoglyceride and PALM treatments compared with SOY and SOPM0 treatment(P<0.05). ADG and G/F were not affected by treatments. Digestibility of fat was higher(P<0.05) for pigs fed SOY diet than fed other diets. SOPM diets containing monoglyceride showed increased fat digestibility compared with PALM diet(P<0.05). SOPM12.5 and SOPM25 treatments were no difference with SOY treatment. However, there were no significant differences in digestibilities of DM, N and DE(P>0.05). Backfat thicknesses were not significantly different among treatments. Pigs fed SOY diet was decreased in serum total cholesterol, HDL-cholesterol, total lipid and was increased in free fatty acid than those fed other diet. Also, triglyceride concentration in serum was increased in PALM treatment compared with SOPM treatment(P=0.06). In conclusion, feeding soybean oil in weaned pigs showed higher fat digestibility and lower cholesterol and triglyceride concentration in serum than feeding only dried palm oil powder. Also, pigs fed monoglyceride were improved fat digestibility compared with those fed dried palm oil powder only.