• Geotechnical Engineering
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• v.11 no.2
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• pp.29-36
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• 1995

Load testis are executed on model reticulated root piles (RRP) to figure out the optimum slanting angle in the piles installation. One set of model RRP consists of 8 slanting piles which are installed in circular patterns forming two concentric circles, each of which is made by 4 piles. Each pile which is a steel bar of 5m in diameter and 300mm in length is coated to become a pile of 6.5mm in diameter. The slanting angle of the model RRP varies from 0$^{\circ}$ to 20$^{\circ}$ Comparing ultimate bearing capacities of the model RRP of different installation angles, it is observed that the ultimate capacities of the RRP increase as the installation angle increases until 15$^{\circ}$, and the optimum slanting angle of the RRP is around 15$^{\circ}$ The ultimate bearing capacity of the 15$^{\circ}$-RRP is found to be 22% bigger than that of the vertical RRP and 120% bigger than that of the circular surface footing whose diameter is same with the circle formed by outer root piles'heads. However, it is noticed that when the slanting angle of the RRP is increased over 15$^{\circ}$, the ultimate capacity starts to be reduced. The ultimate capacity of 20$^{\circ}$-RRP is even smaller than that of the vertical RRP by as much as 5%. From the observation of the load settlement curve obtained during the RRP load tests, it is known that as the slanting angle gets bigger the load -settlement behavior becomes more ductile.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.226-226
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• 2008

지난 10여년 동안 Sn-3.0Ag-0.5(wt%)Cu 합금은 대표 무연솔더 조성으로 다양한 전자제품의 실장 및 접합에 적용되어 왔으며, 그 신뢰성 역시 충분히 검증된 바 있다. 그러나 최근 Ag 가격의 급격한 상승과 솔더 접합부의 내 충격 신뢰성을 보다 향상시키고자 하는 업계의 동향은 Ag의 함량이 낮은 무연솔더 조성의 적용 확대를 유도하고 있다. 이에 따라 본 연구자들은 저 Ag 함유 무연슬더로 Sn-1.2Ag-0.5Cu-0.4In 조성을 제안한 바 있는데, 이는 Sn-3.0Ag-0.5Cu 조성 이상의 solderability를 가지면서도 그 금속원료 가격이 약 20% 가량 저렴한 특징을 가진다. 또한 열 싸이클링 (cycling) 테스트를 통한 슬더 조인트의 신뢰성을 평가한 결과, Sn-3.0Ag-0.5Cu에 크게 뒤떨어지지 않는 양호한 특성이 관찰되었다. 따라서 본 연구에서는 열 싸이클링 테스트와 더불어 최근 그 중요성이 지속적으로 커지고 있는 내 충격 신뢰성 평가 시험을 실시하여 개발된 4원계 무연솔더 조성의 기계적 특성을 기존 무연솔더 조성과 비교, 분석해 보았다. 각 솔더 조성은 솔더 볼 형태로 제조되어 CSP(Chip Scale Package) 상에 범핑 (bumping)되었으며, CSP를 PCB(Printed Circuit Board) 상에 실장하는 공정에서도 Sn-3.0Ag-0.5Cu 및 Sn-1.2Ag-0.5Cu-0.4In의 두 종류의 솔더 페이스트가 사용되었다. 본 연구에서의 내 충격 신뢰성 시험에는 자체 제작한 rod drop 시험기를 사용하였는데, 고정된 CSP 실장 board의 후면 부위를 일정한 높이에서 추를 반복적으로 자유 낙하시켜 급격한 충격을 주는 방식으로 실험을 실시하였다. 이 때 추의 무게는 30g, 낙하 높이는 10cm 였으며, 추의 낙하 시 측정된 board 의 휨 변위량은 약 0.7mm로 측정되었다. 사용된 CSP와 PCB 는 모두 daisy chain 방식으로 연결되어 있기 때문에 저항측정기를 사용한 간단한 실시간 저항 측정 방법으로 시험 이력에 따른 파단부의 발생 시점과 대략의 위치를 손쉽게 확인할 수 있었다. 솔더 조인트의 파단 기준 저항값으로 $1000\Omega$을 설정하였으며. 각 조건 당 5 개 이상의 샘플에 대해 평가를 실시한 후 그 평균값을 조사하였다. 시험 결과 제안된 Sn-1.2Ag-0.5Cu-0.4In 조성은 대표적인 저 Ag 함유 조성인 Sn-1.0Ag-0.5Cu에 비해서는 떨어지는 내 충격 신뢰성을 나타내었지만, 우수한 연성에 기인하여 Sn-3.0Ag-0.5Cu 조성에 비해서는 약 2 배 이상 우수한 신뢰성이 관찰되었다. 또한 CSP의 실장 시 Sn-3.0Ag-0.5Cu보다 Sn-1.2Ag-0.5Cu-0.4In 조성 솔더 페이스트를 적용한 경우에서 보다 우수한 내 충격 신뢰성을 나타내어 기본적으로 개발된 Sn-1.2Ag-0.5Cu-0.4In 솔더 페이스트가 Sn-3.0Ag-0.5Cu 조성의 기존 솔더 페이스트 보다 내 충격 신뢰성이 우수함을 검증할 수 있었다. 각 조성의 솔더 조인트를 $150^{\circ}C$ 에서 500시간 aging한 후 실시한 내 충격 신뢰성 평가에서는 모든 조성에서 그 신뢰성이 급감하는 경항을 나타내었으나, Sn-1.2Ag-0.5Cu-0.4In가 Sn-l.0Ag-0.5Cu보다도 그 상대적인 신뢰성이 우수한 것으로 관찰되었다. 이와 같이 aging 후 실시하는 충격시험은 가장 실제적인 상황과 유사한 조건이므로 상기의 실험 결과는 매우 고무적이었으며, 이에 대한 보다 면밀한 분석이 요청되었다. 마지막으로 파면 및 미세조직 관찰을 통하여 각 조성에서의 충격 파단 특성을 비교, 분석해 보았다.

• Korean Journal of Biological Psychiatry
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• v.14 no.3
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• pp.184-193
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• 2007

Objectives:There is increasing evidence that the cerebellum plays an important role in cognition and psychiatric symptoms as well as motor coordination. The concept of cognitive dysmetria has been making cerebellar function in schizophrenia the focus of current studies. In other words, disruption in the corticocerebellum-thalamic -cortical circuit could lead to disordered cognition and clinical symptoms of schizophrenia. The purposes of this study were to determine cerebellar dysfunction in male schizophrenic patients semiquantitatively with ICARS and to investigate the clinical and cognitive correlates of ICARS in patients. Methods:We compared the scores of cerebellar neurologic sign using ICARS in 47 male patients with a DSM-IV-TR diagnosis of schizophrenia with 30 gender and age-matched healthy control subjects. The semiquantitative 100-point ICARS consists of 19 items divided into 4 unequally weighted subscores:posture and gait disturbances, kinetic functions, speech disorders and oculomotor disorders. All subjects were also assessed with cognitive function test. Cognitive functions were evaluated by Korean-Mini Mental Status Examination (K-MMSE), Verbal fluency test, and Clock drawing test. The patients were administered Korea version of Positive and Negative Symptom Scale(K-PANSS) to assess the symptom severity. Results:Schizophrenic patients had significantly higher scores on the ICARS than control subjects with posture and gait disturbances, kinetic functions, and oculomotor disorders. They also showed more significant impairments in cognitive function tests than control subjects. There was a significant correlation between ICARS and negative symptoms of patients. In cognitive function test, Clock drawing test was significantly associated with negative symptoms. In addition, Clock drawing test was negatively correlated with the total score of ICARS. Conclusion:In this study, we confirmed that schizophrenic patients have significant impairments in cognitive and cerebellar function, and that those were related with negative symptoms of schizophrenic patients. These results support a role of the cerebellum in schizophrenia. It is meaningful that we used a structured, and reliable procedure for rating neurological soft signs, ICARS. We hope that future prospective studies using a similar design help that rate of neurological sign should have been visible with the progression of illness.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.10 no.6
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• pp.425-433
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• 2000

The stochiometric mix of evaporating materials for the $CuGaTe_2$single crystal thin films was prepared from horizontal furnance. Using extrapolation method of X-ray diffraction patterns for the $CuGaTe_2$polycrystal, it was found tetragonal structure whose lattice constant $a_0 and c_0$ were 6.025 $\AA$ and 11.931 $\AA$, respectively. To obtain the single crystal thin films, $CuGaTe_2$mixed crystal was deposited on throughly etched semi-insulator GaAs(100) substrate by the Hot Wall Epitaxy (HWE) system. The source and substrate temperature were $670^{\circ}C$ and $410^{\circ}C$ respectively, and the thickness of the single crystal thin films is 2.1$\mu\textrm{m}$. The crystalline structure of single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). Hall effect on this sample was measured by the method of van der Pauw and studied on carrier density and mobility dependence on temperature. The carrier density and mobility of $CuGaTe_2$single crystal thin films deduced from Hall data are $8.72{\times}10{23}$개 $\textrm m^3$, $3.42{\times}10^{-2}$ $\textrm m^2$/V.s at 293K, respectively. From the photocurrent spectrum by illumination of perpendicular light on the c-axis of the $CuGaTe_2$single crystal thin film, we have found that the values of spin orbit coupling $\Delta$s.o and the crystal field splitting $\Delta$cr were 0.0791 eV and 0.2463 eV at 10 K, respectively. From the PL spectra at 10 K, the peaks corresponding to free bound excitons and D-A pair and a broad emission band due to SA is identified. The binding energy of the free excitons are determined to be 0.0470 eV and the dissipation energy of the donor-bound exciton and acceptor-bound exciton to be 0.0490 eV, 0.0558 eV, respectively.

• Korean Journal of Materials Research
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• v.11 no.3
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• pp.171-177
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• 2001

The thermal and mechanical properties of amorphous Z $r_{62-x}$N $i_{10}$C $u_{20}$A $l_{8}$ $Ti_{x}$ (x=3, 6, 9at%) alloys were investigated. The crystallization process was confirmed as amorphous longrightarrow amorphous + Z $r_2$A $l_3$+ Zr + (Ni,Ti) longrightarrow Z $r_2$Cu + Al + (Ni,Ti) for 3at%Ti, amorphous longrightarrow amorphous + Al longrightarrow $Al_2$Ti + NiZr + CuTi for 6at%Ti and amorphous longrightarrow amorphous + Zr + Al longrightarrow Zr + $Al_2$Zr + Al $Ti_3$+ CuTi for 9at%Ti. lickers hardness ( $H_{v}$ ) increased with increasing volume fraction( $V_{f}$ ) of pricipitates for all concerned compositions. Tensile fracture strength ($\sigma_{f}$ ) showed a maximum value 1219MPa at $V_{f}$ = 38% for 3at%Ti, 1203MPa at $V_{f}$ = 2% for 6at%Ti and 1350MPa at $V_{f}$ = 5% for 9at%Ti. The $\sigma_{f}$ was rapidly decreased after showing the maximum value. The $V_{f}$ corresponding to rapidly decreased $\sigma_{f}$ coincided with the $V_{f}$ transited from ductile to brittle fracture surface.ace.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.10
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• pp.1446-1451
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• 2010

Silk sericin protein was hydrolyzed by seven proteolytic enzymes to examine the effectiveness of the hydrolysates to bind iron. The amino acid nitrogen contents of hydrolysates by Flavourzyme were higher than the others enzymes, and its iron binding capacity showed dose-dependent increase. The bioavailability of iron binding peptide from sericin hydolysates was investigated in iron-deficient rats. Three-week-old male rats were fed iron-deficient diet for three weeks. Rats were divided into four groups (DD: no treated group on iron deficient diet, DD+HI: heme-iron treated group, DD+OI: sericin-Fe, and DD+II: inorganic iron ($FeSO_4$) treated group, and then iron supplemented by injection for one week. After oral administration for one week, the iron contents of serum and liver were significantly higher in DD+OI ($4.2\;{\mu}g/mL$ and $80.1\;{\mu}g/mL$) and DD+HI ($3.2\;{\mu}g/mL$ and $70.6\;{\mu}g/mL$) than DD ($2.0\;{\mu}g/mL$ and $47.9\;{\mu}g/mL$). Hemoglobin content of treated groups was significantly higher than DD, but the significant difference among groups was not shown. Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels did not show any significant difference among all groups. Binding iron to peptide from sericin hydolysates seems to improve its bioavailability and to hasten the cure of iron deficiency in experimental rat.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.36 no.3
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• pp.1-15
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• 2018

This study aims to investigate an aspect of physical palace by reviewing the emergences of tigers and leopards in the palace in Hanyang from the environmental historical perspective. To do so, three topics in environmental history were reviewed including 'environment,' 'impact of human-beings on the environment,' and 'sense and attitude of human-beings on the environment' based on the historical records such as "'Wangjoshilok(王朝實錄)". The results of this study are as follows. First, It was confirmed that leopards and tigers were emerged not only in the palace but also near the City Wall of Hanyang from time to time in Joseon Dynasty. Moreover, tigers lived and propagated in the backyard. Second, This situation may be caused by the natural factors of palace in Hanyang including location, philosophy and technique of building, and so on. That means 'good location' placed by palace worked favorably not only for human-beings but also for the activities of tigers and leopards. Third, In addition to the locational environment, forest policies on the palace and capital may facilitate the emergences of leopards and tigers. With the managements of pine trees, prohibition of burials, prohibition of climbing, prohibition of mountain entrance, and so on, forests were developed in the mountainous territories, which might play a role of shelters or passages for the tigers and leopards. Fourth, It was confirmed that countermeasures on the emergences of tigers in the palace as well as the capital city were different by the kings. Out of these, Jeong-jo was highlighted to seek the realistic countermeasures with actual understanding on the emergences of tigers and leopards. Fifth, In summary, frequent emergences of tigers and leopards in the palace and capital city could be a practical evidence to show 'pro-naturalism' or 'eco-friendliness' of the palace in Joseon which was mentioned superficially, paradoxically speaking. Further studies with the related disciplines are required on the cultural or ecological history of the palace. In addition, it is considered to conduct more detailed scientific studies related to the trend of ecological changes in Joseon.

• Journal of Embryo Transfer
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• v.18 no.3
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• pp.249-255
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• 2003

These studies were performed to improve the reproductive efficiency of gilts and we investigated the effects of puberty periods, first mating time and backfat thickness and will adapt to these results for early selection of excellent gilts. The main results were as follows; 1. First heats on birth season were showed 194.14 day, 163.25 day, 160.25 day and 157.92 day at birth of spring, summer, autumn and winter, respectively and birth of spring was significantly latest among other seasons (p<0.01). 2. First service on birth season were revealed 222.05 day in spring, 193.00 day in summer, 199.20 day in autumn and 190.11 day in winter. birth of spring was significantly latest among others (p<0.01). 3. First heat period of cadidated gilt had 13∼16 mm backfat thickness was 180.32 day, 171.24 day in 17∼20 mm and 162.20 day in 21∼23 mm and was showed delay in thin backfat gilts. There was no differences among backfat thickness. 4. First service of cadidate gilt had 13∼16mm backfat thickness was 211.12 day, 202.43 day in 17∼20 mm and 195.43 day in 21∼23 mm and was showed delay in thin backfat gilts. There was no differences among backfat thickness. 5. The litter size were 9.64 in gilts under 160 day of first heat, 10.14 in 161∼180 day, 9.56 in 181∼200 day and 9.13 in over 201 day. There showed the largest litter size in 161∼180 day of first heat but was no differences. 6. The litter size in gilts under 180 day of first service was 9.13, 9.75 in 181∼200 day, 10.13 in 201∼220 day and 9.45 in over 221 day. There showed the largest litter size in 201∼220 day of first service but was no differences. 7. The litter size of gilt had 13∼16 mm backfat thickness on first service was 9.33, 9.81 in 17∼20 mm and 10.17 in 21∼23 mm and was showed delay in thin backfat gilts. There was no differences among backfat thickness.

• Development and Reproduction
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• v.8 no.2
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• pp.119-122
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• 2004

It is well known that unidentified factors in sera, hormones and growth factors promote the proliferation of granulosa cells and nuclear maturation of bovine COCs in vitro. Attemps had been developed the simple composition of culture media and similar system to in vivo conditions has been applied. In the present study, we investigated the effect of TGF-${\beta}$ on in vitro maturation and in vitro development of Hanwoo COCs. When the COCs were matured in TCM 199 containing 0.1, 1 or 10 ng/ml TGF-${\beta}$ for 24 hrs, metaphaseⅡ of COCs were obtained 95.8%, 100% of matured COCs, respectively and there were no differences among the concentrations of TGF-${\beta}$. Matured COCs with TGF-${\beta}$ cultured in maturation medium after in vitro fertilization, developmental rate to blastocyst were 0~0.8%. Matured COCs with TGF-${\beta}$ were cultured in TCM 199+10% FBS, 0.8% BSA, 0.1% PVA, blastocyst formation were showed in 12.4%, 12.8%, 8.5% of those and cultured in IVMD or IVD without serum were 38.4%, 34.8%, respectively. There were significant differences among the media (P<0.05). TGF-${\beta}$ is available for i vitro maturation of bovine COCs, but further investigation would be need for finding the synergistic autocrine/paracrine fashion of other growth factors in early bovine development.

• Economic and Environmental Geology
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• v.47 no.6
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• pp.571-588
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• 2014

It consists of the Precambrian Jirisan metamorphic complex and Sancheong anorthosite complex and the Mesozoic granitoids which intrude them in the Sancheong area, the Jirisan province of Yeongnam massif, Korea. The study area is located in the western part of the stock-type Sancheong anorthosite complex. We performed a detailed fieldwork on the Sancheong anorthosite (SA) and Fe-Ti ore body (FTO) which constitute the Sancheong anorthosite complex, and reinterpreted the origin of FTO foliation and the genetic relationship between them from the foliations, shear zones, occurrences of the SA and FTO. The new structural characteristics between them are as follows: the multilayer structures of FTO, the derived veins of straight, anastomosing uneven types and block structures related to the size reduction of SA, the gradual or irregular boundaries of SA blocks and FTO showing bulbous lobate margins and comb structures, the FTO foliation and linear arrangements of flow occurrence which is not ductile shear deformation, the discontinuous shear zone of SA, the orientation of FTO foliations parallel to the boundaries of SA blocks, the predominance of FTO foliations toward the boundaries of SA blocks and being proportional to the aspect ratio of plagioclase xenocrysts and SA xenoblocks, and the flow folding structures of FTO foliation. Such field evidences indicate that the SA is not fully congealed when the FTO is melt and the fracturing of partly congealed SA causes the derived veins of FTO and the size reduction of SA. Also the gradual or irregular boundaries of SA blocks and FTO result from the mutual reaction between the not fully congealed SA blocks and the FTO melt, and the FTO foliation is a magmatic foliation which was formed by the interaction between the FTO melt and the partly congealed SA blocks. Therefore, these suggest that the SA and FTO are not formed from the intrusion of different magmas in genesis and age but from a coeval and cogenetic magma through multiple fractionation. We predict that the FTO will show an very irregular occurrence injected along irregular fractures, not the regular occurrence like as the intrusive vein and dike. It can be applied to the designing of Fe-Ti mineral resource exploration in this area.