• 한국세라믹학회지
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• 제38권4호
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• pp.301-301
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• 2001

• 한국재료학회:학술대회논문집
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• 한국재료학회 2009년도 춘계학술발표대회
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• pp.24.1-24.1
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• 2009

The zinc oxide (ZnO) material as the II-VI compound semiconductor is useful in various fields of device applications such as light-emitting diodes (LEDs), solar cells and gas sensors due to its wide direct band gap of 3.37eV and high exciton binding energy of 60meV at room temperature. In this study, the ZnO nanorods were deposited onto homogenous buffer layer/Si(100) substrates by a hydrothermal synthesis. The Effects of the buffer layer annealing and post annealing temperature on the structural and optical properties of ZnO nanorods grown by a hydrothermal synthesis were investigated. For the buffer layer annealing case, the annealed buffer layer surface became rougher with increasing of annealing temperature up to $750^{\circ}C$, while it was smoothed with more increasing of annealing temperature due to the evaporation of buffer layer. It was found that the roughest surface of buffer layer improved the structural and optical properties of ZnO nanorods. For the post annealing case, the hydrothermally grown ZnO nanorods were annealed with various temperatures ranging from 450 to $900^{\circ}C$. Similarly in the buffer layer annealing case, the post annealing enhanced the properties of ZnO nanorods with increasing of annealing temperature up to $750^{\circ}C$. However, it was degraded with further increasing of annealing temperature due to the violent movement of atoms and evaporation. Finally, the buffer layer annealing and post annealing treatment could efficiently improve the properties of hydrothermally grown ZnO nanorods. The morphology and structural properties of ZnO nanorods grown by the hydrothermal synthesis were measured by atomic force microscopy (AFM), field emission scanning electron microscopy (SEM), and x-ray diffraction (XRD). The optical properties were also analyzed by photoluminescence (PL) measurement.

• Bulletin of the Korean Chemical Society
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• 제33권10호
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• pp.3196-3202
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• 2012

Post-synthesis is used to synthesize organic hybrid inorganic mesoporous sieves. In this method, the activity and structure of the base sieve are crucial to obtain the definable hybrid materials. The chemical and physical properties of the base can be largely changed either by the final step of its synthesizing processes, by template removal which is accomplished with the oxidative thermal decomposition (burning) method or by solvent extraction method. In this paper we compared two methods for the post-synthesis of organic hybrid MCM-48. When the template was extracted with HCl/alcohol mixture, the final product showed larger pore size, larger pore volume and better crystallinity compared to the case of the thermal decomposition. The reactivity of the surface silanol group of template free MCM-48 was also checked with an alkylsilylation reagent $CH_2=CHSi(OC_2H_5)_3$. Raman and $^{29}Si$ NMR spectra of MCM-48 in the test reaction indicated that more of the organic group was grafted to the surface of the sample after the template was removed with the solvent extraction method. Direct synthesis of vinyl-MCM-48 was also investigated and its characteristics were compared with the case of post-synthesis. From the results, it was suggested that the structure and chemical reactivity can be maintained in the solvent extraction method and that organic grafting after the solvent extraction can be a good candidate to synthesize a definable hybrid porous material.

• 한국생산제조학회지
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• 제8권3호
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• pp.28-34
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• 1999

The objective of this study is to estimate and to compensate far the volumetric error of a workpiece influenced by the geometric error of a machine tool. In this paper, the volumetric error is defined and the error synthesis model is presented. Then, the volumetric error of workpiece is calculated and compared through the simulation, and a new tool-path is generated to compensate for the error in the post-processor of CAM system using the error synthesis model. By this method, the error is compensated without modification or replacement of a machine tool being in use.

• 대한화학회지
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• 제54권4호
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• pp.411-413
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• 2010

HPA-phosphomolybdic acid 촉매 하에서, 아릴히드라진과 알데히드/케톤을 반응시켜서 치환기를 가지고 있는 indole 화합물을 효율적으로 합성할 수 있는 친환경적인 합성 방법을 개발하였으며, 이때 촉매는 독성이 없으며, 회수하여 재 사용할 수 있다.

• 대한물리의학회지
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• 제7권4호
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• pp.451-458
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• 2012

PURPOSE: The purpose of present study was to determine effects of circuit class training (CCT) on the synthesis of central serotonin in people with post-stroke depression. METHODS: Forty patients with mild post-stroke depression were participated in current study. All subjects were assigned to two groups of CCT (circuit class training) group and SW (stretching and weight shifting) group. Both groups were performed for 80 minutes. The change of blood f-Trp, BCAAs, f-Trp/BCAAs and serotonin according to period training time were examined and the following results were obtained. RESULTS: In the CCT group, f-Trp, BCAAs, and f-Trp/BCAAs increased according to the time point. However, after 24 hour of circuit class training, all of these were significantly decreased by those before training. The change in blood levels of serotonin was the highest in immediately after the training in the CCT group while it was not changed significantly in the SW group. CONCLUSION: It can be seen that CCT can change the serotonin level and have an effect on the synthesis of central serotonin in people with post-stroke depression.

• 대한후두음성언어의학회지
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• 제14권1호
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• pp.30-39
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• 2003

Background and Objectives : Patients with pathologic voice often concern about recovery of voice after surgery. In our investigation, we give controlled values of three parameters of voice synthesis program of Dr. Speech Science. such as jitter, shimmer, and NNE(normalized noise energy) which characterize someone's voice from others and deviced a method to synthesize the predicted voice after performing operation. Subjects and Method : Values of vocal jitter, vocal shimmer, and glottal noise were measured with voices of 10 vocal cord Paralysis and 10 vocal Polyp Patients 1 week Prior to and 1 month after the surgery. With Dr. Speech science voice synthesis program we synthesized 'ae' vowel which is closely identical to preoperative and post-operative voice of the patients by controlling the values of jitter, shimmer, and glottal noise. then we analyzed the synthesized voices and compared with pre and post-operative voice. Results : 1) After inputting the preoperative and corrected values of jitter, shimmer, and glottal noise into the voice synthesis Program, voices identical to vocal Polyp Patients' Pre- and Postoperative voices withiin statistical significance were synthesized 2) After elimination of synergistic effects between three paramenter, we were able to synthesize voice identical to vocal paralysis patients' preoperative voices. 3) After inputting only slightly increased jitter, shimmer into the synthesis program, we were able to synthesize voice identical to vocal cord paralysis patients' postoperative voices. Conclusion : Voices synthesized with Dr. Speech science program were identical to patients' actual pre and postoperative voice, and clinicians will be able to give the patients more information and thus increased patients cooperability can be expected.

• Journal of Power Electronics
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• 제16권6호
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• pp.2258-2271
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• 2016

In this paper, some crucial performance characteristics related to the operational reliability of the post-fault Pulse Width Modulated (PWM) rectifiers, such as line current harmonic distortion, Common Mode Voltage (CMV), and current stress on the capacitors, are fully investigated. The aforementioned performance characteristics of post-fault rectifiers are highly dependent on the utilized space vector modulation (SVM) schemes, which are also examined. Detailed analyses of the three most commonly used SVM schemes for post-fault PWM rectifiers are provided, revealing the major differences in terms of the zero vector synthesis approaches. To compare the performances of the three SVM schemes, the operating principles of a post-fault rectifier are presented with various SVM schemes. Using analytical and numerical methods in the time domain, the performances of the line current distortion, common mode voltage and capacitor current are evaluated and compared for each SVM scheme. The proposed analysis demonstrates that the zero vector synthesis approaches of the considered methods have significant impacts on the performance characteristics of rectifiers. In addition, the advantages and disadvantages of the proposed SVM schemes are discussed. The experimental results verify the effectiveness and validity of the proposed analysis.

• Asian-Australasian Journal of Animal Sciences
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• 제22권6호
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• pp.865-870
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• 2009

In this study, we have attempted to understand the effects of taurine on serum and liver concentrations of cholesterol and triglycerides in broiler chickens and mice in the post-absorptive state, and on in vitro protein synthesis in the livers of broiler chickens and laying hens, as well as the effects of taurine on in vivo protein synthesis in the liver of mice. The experimental animals were subjected to 24 h of starvation in order to perpetuate a post-absorptive state. Serum concentrations of high density lipoprotein cholesterol and triglycerides were significantly (p<0.05) higher in the taurine groups than in the controls in both the broilers and the mice. However, taurine resulted in a significant (p<0.05) reduction in liver concentrations of total cholesterol and triglycerides, relative to what was seen in the control groups of both animals. Taurine stimulated the in vitro synthesis of 57-kDa, 40-kDa and 23-kDa proteins in the liver of broilers, but inhibited the in vitro synthesis of 54-kDa, 37-kDa and 24-kDa proteins. Taurine in the liver of laying hens exerted effects on in vitro protein synthesis, with the exception of the 26-kDa protein which was not detected in broiler liver, but was inhibited by taurine in the liver of laying hens. Unlike the findings regarding in vitro protein synthesis in the liver of broilers or laying hens, taurine appeared to stimulate the synthesis of only two proteins, a 47-kDa and a 40-kDa protein, in the liver of mice. Overall, theses findings indicate that taurine treatment results in a reduction in cholesterol and triglyceride concentrations, and also affects protein synthesis in the livers of broilers, laying hens, and mice.

• 한국정보통신학회논문지
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• 제26권10호
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• pp.1537-1544
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• 2022

application specific integrated circuit (ASIC) 및 system on chip (SoC) 설계 시 디지털 회로는 클럭에 동기화되어 작동한다. 칩 설계 시, place & route (P&R)에서 설계 조건과 타이밍 조건, 클럭의 동기화 여부 등을 고려한다. P&R에서 클럭 경로에 대한 delay를 줄이기 위해, clock tree synthesis (CTS) 기법을 이용한다. 본 논문에서는 사전 클럭트리 합성 가능 여부 판단을 위한 shallow-CTS 알고리즘을 소개한다. 오픈 소스 Parser-Verilog를 사용하여 register transfer level (RTL) 합성가능한 Verilog를 파싱하여, Pre-CTS와 Post-CTS 단계를 진행하고, 가장 긴 clock path와 버퍼 삽입 전후의 표준편차를 비교하여 CTS의 정확도에 대해 분석한다. 본 논문에서 시간 투입이 많이 되는 licensed EDA tool을 사용하여 CTS 결과를 확인하지 않고, RTL 수준에서 사전 클럭 트리 합성 검증 방법을 제공하여 비용 및 시간문제를 감소할 수 있을 것으로 기대된다.