• 한국전자파학회논문지
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• 제18권8호
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• pp.887-894
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• 2007

본 논문에서는 전기 결합 구조와 추가된 개방 스터브를 이용해 제이 가능한 4개의 전송 영점을 갖는 저역 통과 필터를 설계 및 제작하였다. 필터의 통과 대역은 GSM 대역이며, 전기 결합에 의해 WiBro 및 위성 DMB 대역에서 전송 영점이 각각 발생한다. 또한, 임의의 상측 주파수에서 개방 스터브에 의해 추가적인 2개의 전송 영점이 발생하는 구조이다. 적은 기생 성분을 갖는 준집중 소자를 이용해 필터를 구현함으로써 차단 대역의 고조파 성분을 억제하였다. 유한 전송 영점의 제어를 위한 등가 회로의 전기 결합 성분인 $C_M$은 필터 구조의 개방 스터브 간 간격 조절을 통해 구현하였다. 유전율 2.6인 테프론 기판을 사용하여 제작된 필터의 전체 크기는 급전선로를 포함하여 $38{\times}20{\times}0.79mm^3$이다. 측정된 3dB 차단 주파수는 1.55GHz이며, 전송 영점의 위치는 각각 2.20, 2.43, 4.11 및 6.84 GHz이다.

• 한국전기전자재료학회논문지
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• 제27권1호
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• pp.14-17
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• 2014

In this study, lead-free Piezoelectric $(Na_{0.47}K_{0.47}Sr_{0.03}Ca_{0.03})(Nb_{0.94}Ti_{0.06})O_3$-0.1 $MnO_2$ ceramics were fabricated using mixed oxide method and the effects of various sintering temperature on the structural and electrical properties were investigated. For the $(Na_{0.47}K_{0.47}Sr_{0.03}Ca_{0.03})(Nb_{0.94}Ti_{0.06})O_3$-0.1 $MnO_2$ (NKN-SCT-$MnO_2$) ceramics sintered at temperatures of $1,025{\sim}1,100^{\circ}C$. The results indicated that all specimens were perovskite single phase formation without any second phase. It has been shown that relative density is increased to increasing sintering temperature. When the sintered temperature at $1,075^{\circ}C$, highest sintered density and maximum value of $4.45g/cm^3$. Average grain size is increased to increasing sintering temperature. The electromechanical coupling factor, dielectric constant, dielectric loss, d33 and curie temperature at the sintering temperature $1,075^{\circ}C$ of NKN-SCT-$MnO_2$ specimens were 0.22, 511, 0.033, 103 and $380^{\circ}C$, respectively.

• Asian-Australasian Journal of Animal Sciences
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• 제26권5호
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• pp.668-674
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• 2013

An in vitro fermentation was conducted to determine the effects of hainanmycin on protein degradation and populations of ammonia-producing bacteria. The substrates (DM basis) for in vitro fermentation consisted of alfalfa hay (31.7%), Chinese wild rye grass hay (28.3%), ground corn grain (24.5%), soybean meal (15.5%) with a forage: concentrate of 60:40. Treatments were the control (no additive) and hainanmycin supplemented at 0.1 (H0.1), 1 (H1), 10 (H10), and 100 mg/kg (H100) of the substrates. After 24 h of fermentation, the highest addition level of hainanmycin decreased total VFA concentration and increased the final pH. The high addition level of hainanmycin (H1, H10, and H100) reduced (p<0.05) branched-chain VFA concentration, the molar proportion of acetate and butyrate, and ratio of acetate to propionate; and increased the molar proportion of propionate, except that for H1 the in molar proportion of acetate and isobutyrate was not changed (p>0.05). After 24 h of fermentation, H10 and H100 increased (p<0.05) concentrations of peptide nitrogen and AA nitrogen and proteinase activity, and decreased (p<0.05) $NH_3$-N concentration and deaminase activity compared with control. Peptidase activitives were not affected by hainanmycin. Hainanmycin supplementation only inhibited the growth of Butyrivibrio fibrisolvens, which is one of the species of low deaminative activity. Hainanmycin supplementation also decreased (p<0.05) relative population sizes of hyper-ammonia-producing species, except for H0.1 on Clostridium aminophilum. It was concluded that dietary supplementation with hainanmycin could improve ruminal fermentation and modify protein degradation by changing population size of ammonia-producing bacteria in vitro; and the addition level of 10 mg/kg appeared to achieve the best results.

• Asian-Australasian Journal of Animal Sciences
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• 제26권6호
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• pp.755-765
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• 2013

The accumulation of inbreeding and the loss of genetic diversity is a potential problem in the modern swine breeds in China. Therefore, the purpose of this study was to analyze the pedigrees of Chinese Duroc (CD), Landrace (CL) and Yorkshire (CY) swine to estimate the past and current rates of inbreeding, and to identify the main causes of genetic diversity loss. Pedigree files from CD, CL and CY containing, 4529, 16,776 and 22,600 records, respectively, were analyzed. Pedigree completeness indexes of the three breeds, accounting for one generation back, were 83.72, 93.93 and 93.59%, respectively. The estimated average annual inbreeding rates for CD, CL and CY in recent three years were 0.21, 0.19 and 0.13%, respectively. The estimated average percentage of genetic diversity loss within each breed in recent three years was about 8.92, 2.19, and 3.36%, respectively. The average relative proportion of genetic diversity loss due to unequal contributions of founders in CD, CL and CY was 69.09, 57.95 and 60.57%, and due to random genetic drift was 30.91, 42.05 and 39.43%, respectively. The estimated current effective population size for CD, CL and CY was 76, 117 and 202, respectively. Therefore, CD has been found to have lost considerable genetic diversity, demanding priority for optimizing the selection and mating to control future coancestry and inbreeding. Unequal contribution of founders was a major cause of genetic diversity loss in Chinese swine breeds and random genetic drift also showed substantial impact on the loss of diversity.

• Asian Pacific Journal of Cancer Prevention
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• 제15권20호
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• pp.8765-8774
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• 2014

This study aimed at summarizing epidemiological research findings on associations between tobacco, alcohol and tea consumption and risk of gastric cancer (GC) in the Chinese population. The review searched PubMed, Embase, China National Knowledge Infrastructure (CNKI) and China Biology Medicine (CBM) databases and reference lists of review papers for all studies published in English or Chinese languages. Information extracted, via two independent researchers, from retrieved articles included first author, year of publication, study design, sample size, source of controls and adjusted odds ratio (OR) or relative risk (RR) with the corresponding 95% confidence intervals (CIs) for each category. Statistical analyses used software STATA version 12.0. The systematic search found 89 articles containing 25,821 GC cases and 135,298 non-cases. The overall random effects in terms of pooled OR and 95%CI for tobacco, alcohol and tea consumption were 1.62 (95%CI: 1.50-1.74), 1.57 (95%CI: 1.41-1.76) and 0.67 (95%CI: 0.59-0.76) respectively; while the heterogeneity among included studies ranged from 80.1% to 87.5%. The majority of subgroup analyses revealed consistent results with the overall analyses. All three behavioral factors showed statistically significant dose-dependent effects on GC (P<0.05). The study revealed that tobacco smoking and alcohol drinking were associated with over 1/2 added risk of GC, while tea drinking conferred about 1/3 lower risk of GC in the Chinese population. However, these results should be interpreted with caution given the fact that most of the included studies were based on a retrospective design and heterogeneity among studies was relatively high.

• Asian Pacific Journal of Cancer Prevention
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• 제14권10호
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• pp.6165-6171
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• 2013

This study aimed to analyze the expression and clinical significance of cyclin G2 (CCNG2) in thyroid carcinoma and the biological effects of CCNG2 overexpression in a cell line. Immunohistochemistry and Western blotting were used to analyze CCNG2 protein expression in 63 cases of thyroid cancer and normal tissues to allow the relationship with clinical factors to be assessed. CCNG2 lentiviral and empty vectors were transfected into the thyroid cancer K1 cell line. Reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting were applied to detect the mRNA and protein levels of CCNG2. MTT assay and cell cycle were also conducted to assess the influence of up-regulated expression of CCNG2 on K1 cell biology. The level of CCNG2 protein expression was found to be significantly lower in thyroid cancer tissue than normal tissues (P<0.05). Western blot: The relative amount of CCNG2 protein in thyroid cancer tissue was respectively found to be significantly lower than in normal tissues (P<0.05), correlating with lymph node metastasis, clinic stage and histological grade (P<0.05), but not gender, age or tumor size (P>0.05). Loss of CCNG2 expression correlated significantly with poor overall survival time on Kaplan-Meier analysis (P<0.05). The results for biological functions showed that K1 cell transfected CCNG2 had a lower survival fraction, a greater percentage in the G0/G1 phases, and lower cyclin-dependent kinase 2 (CDK2) protein expression compared with K1 cells non-transfected with CCNG2 (P<0.05). CCNG2 expression decreased in thyroid cancer and correlated significantly lymph node metastasis, clinic stage, histological grade and poor overall survival, suggesting that CCNG2 may play important roles as a negative regulator in thyroid cancer K1 cells by promoting degradation of CDK2.

• 한국수산과학회지
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• 제21권4호
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• pp.246-258
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• 1988

진주만에 분포하는 점토광물의 평균 함량비는 iillite $55.1\%,\;kaolinite\;23\%,\;chlorite\;22.5\%$, 그리고 smectite가 $0.4\%$이다. 부근의 남해 대륙붕에 비해 illite는 $10\~20\%$ 정도 낮고, kaolinite는 $10\%$ 정도 더 높다. 남강의 방류로 인해 조립질 퇴적물이 대량으로 유입되는 진주만 동북쪽 지역인 사천만을 제외하면 진주만에 분포하는 세립질 퇴적물은 초량천등 하동-산청 지역의 고령토 지대를 집수구역으로 하는 하천들이 주 공급원이고, 일부는 비교적 활발한 조수유동으로 노량수도와 삼천포수도를 통하여 대륙붕으로 부터 공급되었으리라 생각된다. 또한, 진주만 중앙부의 수심이 얕은 지역은 관곡천에서 진교만으로 유인된 퇴적물의 퇴적작용에 영향을 받은 것으로 생각된다.

• 유통과학연구
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• 제13권3호
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• pp.69-77
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• 2015

Purpose - The purpose of this study is to examine whether the cash policies of retail firms listed on Korean stock markets are consistent with the evidence provided in the study of Almeida et al. (2004). Liquidity management is an important issue for financially constrained firms relative to financially unconstrained firms. Because there are few sources of external funding, the optimal liquidity policies of financially constrained firms should reflect their own earnings or cash inflows to create opportunities for current and future real investments. According to this simple idea, we estimate the sensitivity of cash to cash flows and simply check whether the estimated sensitivity to cash flows of the cash retained by constrained retail firms is greater than that of the cash retained by unconstrained retail firms. Through this work, we aim to explain why the cash policies of the retail firms listed on the Korean stock markets differ from those of listed manufacturing enterprises. Research design, data, and methodology - To explain a firm's cash holdings, we use only three explanatory variables: earnings before interest and taxes (EBIT), Tobin's q, and size. All the variables are defined as the value of the numerator divided by aggregate assets. Thanks to this definition, it is possible to treat all the sample firms as a single large firm. The sample financial data for this study are collected from the retail enterprises listed on the KOSPI and KOSDAQ markets from 1991 to 2013. We can obtain these data from WISEfn, the financial information company. This study's methodology has its origin in Keynes's simple idea of precautionary liquidity demand: When a firm faces financial constraints, cash savings from earnings or cash inflows become important from the corporate finance perspective. Following this simple idea, Almeida et al. (2004) developed their theoretical model and found empirical evidence that the sensitivity of cash to cash flows varies systematically according to different types of financing frictions. To find more empirical evidence for this idea, we examined the cash flow sensitivity of the cash held by Korean retail firms. Results - Through several robustness tests, we empirically showed that financially constrained Korean retail firms display significant positive propensity to save cash from earnings before interest and taxes, while the estimated cash flow sensitivity of the cash held by unconstrained retail firms is not significant. Despite the relatively low earnings of retail firms, their sensitivity is three times greater than that of manufacturing enterprises. This implies that Korean retail firms have greater intentions of facilitating future investments rather than current investments. Conclusions - The characteristics of the cash policies of Korean retail firms differ from those of manufacturing firms. This contrast may be attributable to industry-oriented policy planning, regulations, and institutional differences. However, the industrial policymakers should observe signals of the long-term growth options of retail firms based on their high propensity to save from their cash inflows.

• Asian-Australasian Journal of Animal Sciences
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• 제31권1호
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• pp.63-70
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• 2018

Objective: The aim of the study was to isolate gossypol-degrading bacteria and to assess its potential for gossypol degradation. Methods: Rumen liquid was collected from fistulated cows grazing the experimental pasture. Approximately 1 mL of the rumen liquid was spread onto basal medium plates containing 2 g/L gossypol as the only source of carbon and was then cultured at $39^{\circ}C$ to isolate gossypol-degrading bacteria. The isolated colonies were cultured for 6 h and then their size and shape observed by microscope and scanning electron microscope. The 16S rRNA gene of isolated colonies was sequenced and aligned using National Center for Biotechnology Information-Basic Local Alignment Search Tool. The various fermentation conditions, initial pH, incubation temperature, inoculum level and fermentationperiod were analyzed in cottonseed meal (CSM). The crude protein (CP), total gossypol (TG), and free gossypol (FG) were determined in CSM after fermentation with isolated strain at $39^{\circ}C$ for 72 h. Results: Screening results showed that a single bacterial isolate, named Rumen Bacillus Subtilis (RBS), could use gossypol as a carbon source. The bacterium was identified by 16S rDNA sequencing as being 98% homologous to the sequence of Bacillus subtilis strain GH38. The optimum fermentation conditions were found to be 72 h, $39^{\circ}C$, pH 6.5, moisture 50%, inoculum level $10^7cell/g$. In the optimum fermentation conditions, the FG and TG content in fermented CSM decreased 78.86% and 49% relative to the control. The content of CP and the essential amino acids of the fermented CSM increased respectively, compared with the control. Conclusion: The isolation of a gossypol-degrading bacterium from the cow rumen is of great importance for gossypol biodegradation and may be a valuable potential source for gossypol-degradation of CSM.

• 한국멀티미디어학회논문지
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• 제11권9호
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• pp.1296-1301
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• 2008

초음파 영상은 초음파 펄스를 이용하여 반사파를 수신하여 진단에 필요한 영상을 구성하는데 신호가 약해 질 경우 잡음이 발생하며 미세한 명암도 차이 등에 의해 분석 과정에서 육안으로 인지하고 진단하는데 어려움이 있다. 특히 근골격계 검사를 위한 초음파 영상에서 근육 영역의 진단에 어려움을 준다. 따라서 본 논문에서는 초음파 영상에서 영상 처리 기법을 이용하여 근육 영역을 검출할 수 있는 방법을 제안한다. 초음파 영상에서의 근육 영역 검출은 피하지방층과 기타 영역 그리고 근육을 둘러싸고 있는 근막 후보 영역을 검출한 후, 위치 정보와 형태학적 특징을 이용하여 최종적으로 근막 내부 영역인 근육 영역을 검출한다. 제안된 방법의 근막 후보 영역의 검출 과정은 개선된 히스토그램 스트레칭과 Multiple 연산으로 대비차를 향상시키고 반복 이진화 기법을 적용한 후, 잡음에 의해 손실되거나 끊어진 근막 영역을 거리 및 방향 분석을 이용하여 연결한 후에 근막 후보 영역을 검출한다. 검출된 근막 후보 영역의 형태학적 특징과 위치정보를 이용하여 피하지방층과 기타 영역을 분류한 후, 최종적으로 근육 영역을 검출한다. 실제 초음파 영상을 대상으로 제안된 근육 검출 방법을 적용하여 검출된 근육 영역과 전문의가 분석한 근육 영역을 비교한 결과, 제안된 근육 검출 방법이 전문의가 육안으로 분석한 근육 영역과 근접하게 검출되어 본 논문에서 제안한 근육 영역 검출 방법이 효율적임을 확인하였다.