• Bulletin of the Korean Chemical Society
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• 제19권9호
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• pp.927-933
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• 1998

Polycrystalline powder of vanadium-doped forsterite (Vδ $Mg_2SiO_4$) was synthesized by the $H_2O_2$-assisted sol-gel method. The vanadium dopant, which was added as VO$(OMe)_3$ in methanol, went through several redox reactions as the sol-gel reaction proceeded. Upon adding VO$(OMe)_3$ to a mixture of $Mg(OMe)_2$ and Si$(OEt)_4$ in methanol, V(V) reduced to V(IV). As hydrolysis reaction proceeded, the V(IV) oxidized all back to V(V). Apparently, some of the V(V) reduced to V(IV) during subsequent gelation by condensation reaction. The V(IV) remained even after heat treatment of the gel in highly oxidizing atmosphere. The crystallization of the xerogel around 880 ℃ readily produced single phase forsterite without any minor phase. Using the polycrystalline powder as feeding stock, single crystals of vanadium-doped forsterite were grown by the floating zone method in oxidizing or reducing atmosphere. The doping was limited in low level because of the high partitioning of the vanadium in liquid phase during melting. The greenish single crystal absorbed visible light of 700∼1100 nm. But, no emission was obtained in near infrared range.

• 한국컴퓨터정보학회논문지
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• 제11권3호
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• pp.161-166
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• 2006

본 논문은 시간 제약 조건하에서의 모듈 선택 재사용을 이용한 CPLD 저전력 기술 매핑을 제안한다. 일반적인 상위 수준 합성에서의 스케줄링은 실제적인 라이브러리의 복잡한 재사용을 허용하지 않는다. 반면 제안한 알고리즘은 주어진 사용자 정의 모듈을 실제적인 RT 라이브러리 모듈 재사용과 공유된 자원에서의 스위치 활동의 자원 공유하여 스케줄링을 수행한다. 스케줄링은 체이닝과 멀티사이클링을 이용해 다양한 상위 레벨 벤치마크의 환경에서 최적의 스케줄링의 결과를 얻는다. 스케쥴링의 결과 재사용된 자원은 CPLD 저전력 기술 매핑 알고리즘을 이용하여 저전력으로 회로를 구현한다.

• 한국컴퓨터정보학회논문지
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• 제23권1호
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• pp.33-39
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• 2018

In this paper, We studied the possibility of SoC(System On Chip) design using infrared image processing IP(Intellectual Property). And, we studied NUC(Non Uniformity Correction), BPR(Bad Pixel Recovery), and CEM(Contrast Enhancement) processing, the infrared image processing algorithm implemented by IP. We showed the logic and timing diagram implemented through the hardware block designed based on each algorithm. Each algorithm was coded as RTL(Register Transfer Level) using Verilog HDL(Hardware Description Language), ALTERA QUARTUS synthesis, and programed in FPGA(Field Programmable Gated Array). In addition, we have verified that the image data is processed at each algorithm without any problems by integrating the infrared image processing algorithm. Particularly, using the directly manufactured electronic board, Processor, SRAM, and FLASH are interconnected and tested and the verification result is presented so that the SoC type can be realized later. The infrared image processing IP proposed and verified in this study is expected to be of high value in the future SoC semiconductor fabrication. In addition, we have laid the basis for future application in the camera SoC industry.

• Nuclear Engineering and Technology
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• 제54권8호
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• pp.2999-3005
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• 2022

The new experimental setup has been built at the 11b channel of the IBR-2 research reactor at FLNP, JINR, to study the elemental composition of samples by registration of prompt gamma emission during thermal neutron capture. The setup consists of a curved mirror neutron guide and a radiation-resistant HPGe high-purity germanium detector. The detector is surrounded by lead shielding to suppress the natural background gamma level. The sample is placed in a vacuum channel and surrounded by a LiF shield to suppress the gamma background generated by scattered neutrons. This work presents characteristics of the experimental setup. An example of hydrogen concentration determining in a diamond powder made by detonation synthesis is given and on its basis, the sensitivity of the setup is calculated being ~4 ㎍.

• 한국전기전자재료학회논문지
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• 제35권4호
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• pp.359-365
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• 2022

The development of efficient electron donor (or hole-transporting) molecules that can be used in various optoelectronic device fields is highly demanded. In this work, a novel class of triptycene-based three-dimensional (3D) triphenylamine (TI-TPA) derivatives with different end substituents was designed and prepared for transparent electron donor materials. Owing to the rigid 3D triptycene framework, the obtained TI-TPA derivatives had an amorphous morphology with high thermal decomposition temperature. The oxidation potential of these TI-TPA derivatives decreased as the electron donating strength of the end substituent increased. Among TI-TPA derivatives, TI-TPA-OMe exhibited the highest HOMO level (-5.31 eV) which is similar to that of Spiro-OMeTAD (-5.22 eV). In addition, TI-TPA-OMe was found to form a strong charge transfer complex with the triptycene-based acceptor TI-BQ, leading to a new absorption band at around 640 nm. These results can be applied for developing efficient electron donor materials that can mimic the advantages of the spiro-linked structure and TPA units of Spiro-OMeTAD.

• Journal of Animal Science and Technology
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• 제46권1호
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• pp.61-68
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• 2004

본 연구는 monosodium glutamate의 생산 후 발생되는 부산물인 condensed molasses solubles(CMS)가 반추가축의 질소 공급원으로서 반추위 미생물 단백질 합성에 미치는 효과를 조사하기 위하여 수행하였다. 반추위 canulae가 부착된 4마리의 비착유소를 4 ${\times}$ 4 라틴 방각법에 적용하여 실험을 수행하였으며, 4개의 처리구는 다음과 같다. (1) 기초사료(앞착된 보리 3kg/일과 보리짚의 자유채식), (2) 기초사료에 당밀 200g/일 그리고 물 300g/일 첨가, (3) 기초사료에 당밀 200g/일, CMS 100g/일 그리고 물 200g/일 첨가 (4) 기초 사료에 당밀 200g/일, CMS 200g/일, 그리고 물 100g/일 첨가. CMS의 첨가수준에 따른 반추위내 발효양상은 처리구간에 유의적인 차이가 없었으나, CMS를 200g/일을 첨가한 처리구가 다른 처리구들에 비해 반추위내 미생물 단백질 합성량의 표시로서 이용된 allantoin/creatinine의 비율을 증가시키는 경향이 나타났다(P < 0.10).

• 한국산업보건학회지
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• 제10권2호
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• pp.124-139
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• 2000

This study was performed to investigate monoacetylbenzidine(MABZ) and benzidine(BZ) hemoglobin adducts among workers who worked at benzidine based dye manufacturing company, and exposed by benzidine and benzidine based dye. The hemoglobin adducts were compared with work environment assessment result for evaluating the usefulness of biological monitoring. The mean BZ hemoglobin adducts among the first synthesis worker's hemoglobin adducts were $40.69{\mu}gBZ/g$ Hb and those of dry and packing workers were $22.14{\mu}gBZ/g$ Hb. The mean of MABZ hemoglobin adducts among 1st synthesis workers were $255.84{\mu}gMABZ/g$ Hb, dispersion worker's hemoglobin adducts were $76.17{\mu}gMABZ/g$ Hb and synthesis worker's hemoglogin adducts were $28.66{\mu}gMABZ/g$ Hb. Work environment assessment results during past 3 years were $0.0065mg/m^3$ and $0.5659mg/m^3$ of benzidine based dye concentration in ambient air of drying and packing only. Dye producing process was categorized by the possibility of exposure to benzidine and benzidine based dye. BZ and MABZ hemoglobin adducts were $19.55{\mu}gBZ/g$ Hb, $119.80{\mu}gMABZ/g$ Hb among workers who exposed by benzidine dihydrochloride and $16.32{\mu}gBZ/g$ Hb, $316.56{\mu}gMABZ/g$ Hb among workers who exposed by benzidine based dye. BZ hemoglobin adducts were not detected among control group and MABZ hemoglobin adducts were $5.33{\mu}gMABZ/g$ Hb. The differences between control and other exposed group was statistically significant. But there was no statistically significant differences between benzidine dihydrochloride exposed process and benzidine based dye exposed group. BZ and MABZ hemoglobin adducts were $2.23{\mu}gBZ/g$ Hb, $76.17{\mu}gMABZ/g$ Hb and $3.46{\mu}gBZ/g$ Hb, $21.33{\mu}gMABZ/g$ Hb. So hemoglobin adducts of MABZ were 5 ~ 30 time higher than those of BZ(P<0.003). Above results indicate that work environment assessment didn't detected benzidine and benzidine based dye in ambient air but biological monitoring detected those of hemoglobin adducts. Two group's hemoglobin adducts exposed benzidine dihydrochloride and benzidine based dye were high level but wasn't statistically significant and those were not detected in control group.

• 한국지구과학회지
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• 제26권5호
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• pp.387-394
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• 2005

본 연구는 과학 영재 프로그램을 개발하고 개선하는데 반영하고자 2002년도 서울 대학교 과학 영재 교육센터에서 운영된 과학 영재 프로그램의 각 주제에 제시된 학습 목표, 과학적 모형, 과학 탐구의 인지 과정을 분석하였다. 교육 목표와 과학적 모형, 탐구 활동의 세 요소들은 과학 교육 과정의 구성에 있어서 중요하다는 판단 아래 각 요소들이 제시된 정도를 파악한 후 이들의 수준이 영재 학생들의 인지적 요구를 충족시키는지에 초점을 두어 분석 결과를 해석하였다. 이에 따라 교육 목표의 인지 영역 중에서 상위 사고력 영역에 해당하는 종합 영역, 과학적 모형 중에서 상위수준의 추상성과 복잡성 모형인 다 개념-과정 모형, 과학 탐구의 인지 과정 중 창의성 영역에 해당하는 실험 설계의 인지 과정이 과학 영재 학생들을 가르치는 데 중요한 항목임을 전제하였다. 분석 결과 서울 대학교 과학 영재 프로그램의 각 주제에 제시된 교육 목표는 상위사고력 영역과 하위사고력 영역이 비슷한 비율로 나타나며, 그 중에서 종합 영역은 낮게 나타났다. 과학적 모형은 다 개념-과정 모형보다는 단일 개념 모형이 많았으며 추상성 수준은 중간 정도였다. 과학 탐구의 인지 과정은 실제 과학 탐구의 인지 과정을 고르게 다루지는 않았다. 특히 실험 설계의 인지 과정은 적게 다루고 있었다. 따라서 분석한 과학 영재 프로그램이 과학 영재들의 인지적 요구를 충족시키기 위해서는 종합 영역의 교육 목표, 다 개념-과정 모형, 실험 설계의 인지 능력을 더 많이 반영해야 한다.

• Asian-Australasian Journal of Animal Sciences
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• 제26권4호
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• pp.529-536
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• 2013

The objective of this study was to investigate the effect of levels of cottonseed meal with various carbohydrate sources in concentrate on feed intake, nutrient digestibility, rumen fermentation and microbial protein synthesis in dairy bulls. Four, 6 months old dairy bulls were randomly assigned to receive four dietary treatments according to a $2{\times}2$ factorial arrangement in a $4{\times}4$ Latin square design. Factor A was carbohydrate source; cassava chip (CC) and cassava chip+rice bran in the ratio of 3:1 (CR3:1), and factor B was cotton seed meal levels in the concentrate; 109 g CP/kg (LCM) and 328 g CP/kg (HCM) at similar overall CP levels (490 g CP/kg). Bulls received urea-lime treated rice straw ad libitum and were supplemented with 10 g of concentrate/kg BW. It was found that carbohydrate source and level of cotton seed meal did not have significant effects on ruminal pH, ammonia nitrogen concentration, microbial protein synthesis or feed intake. Animals which received CC showed significantly higher BUN concentration, ruminal propionic acid and butyric acid proportions, while dry matter, organic matter digestibility, populations of total viable bacteria and proteolytic bacteria were lower than those in the CR3:1 treatment. The concentration of total volatile fatty acids was higher in HCM than LCM treatments, while the concentration of butyric acid was higher in LCM than HCM treatments. The population of proteolytic bacteria with the LCM treatments was higher than the HCM treatments; however other bacteria groups were similar among the different levels of cotton seed meal. Bulls which received LCM had higher protein digestibility than those receiving HCM. Therefore, using high levels of cassava chip and cotton seed meal might positively impact on energy and nitrogen balance for the microbial population in the rumen of the young dairy bull.

• Journal of Periodontal and Implant Science
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• 제28권2호
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• pp.235-247
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• 1998

Calcium sulfate has a long history of medical use as an implant material. The biocompatibiliry of the material has been clearly established. Bone ingrowth concomitant with resorption occurs rapidly with efficient conduction of bone from particle to particle. Calcium sulfate also has a potential for functioning as a good bamer membrane. The purpose of this study was to compare the biocompatibility of different types of calcium sulfate grafting materials including an expelimental calcium sulfate compound on periodontal ligament cells in vitro as a preliminary test towards the development of a more convenient and useful form of grafting material which could promote regeneration of periodontal tissue. Human periodontal ligament cells were collected from the premolar teeth extracted for orthodontic treatment. cells were cultured in a.MEM culture medium containing 20% FBS, at $37^{\circ}C$ and 100% humidity, in a 5% CO2 incubator. Cells were cultured into 96 well culture plate $1{\times}104$ cells per well with $\alpha$-MEM and incubated for 24 hours. After discarding the medium, those cells were cultured in $\alpha$-MEM contained with 10% FBS alone (control group), in medcal-grade calcium sulfate(MGCS group), in plaster(plaster group), experimental calcium sulfate paste(CS paste group) for 1, 2, 3 day respectively. And then each group was characterized by examining of the cell counting, MTI assay, collagen synthesis. The results \vere as follows. 1. In the analysis of cell proliferation by cell counting, both medical-grdde calcium sulfate group and plaster group showed no stastically significant difference at day 1, 2, 3 accept for plaster group at day 1 compared to control group, but there was stastically significant difference between CS paste group and all other groups at day 1, 2, 3(P<0.05). 2. In the analysis of cytotoxicity by MIT assay, both medical-grade calcium sJlfate group and plaster group showed no stastically significant difference compared to control group at day 1, 2, 3 but there was stastically significant difference between CS paste group and all other groups at day 1, 2, 3(P<0.OS). 3. In the analysis of collagen synthesis by immunoblotting assay, high level was detected for medical-grade calcium sulfate group and plaster group at day 1, 2, 3 compared to CS paste group. On the basis of these results, medical-grade calcium sulfate and plaster was shown to possess biocompatibility whereas the CS paste had unfavourable outcome. This observation shows a need for modification of the materials contained in calcium sulfate paste.