• 한국산림과학회지
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• 제105권3호
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• pp.330-335
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• 2016

본 연구는 중부지방소나무 등 주요 5개 수종에 대하여 상업적으로 이용가능한 재적율인 조재율을 구하기 위하여 수행되었다. 본 연구에 이용한 자료는 최소 1,300여본 이상의 전국적인 조사자료를 이용하였으며, 적용한 추정식은 임목재적 중 목질부 재적을 나타내는 목질부 재적율 추정식과 목질부 재적에 대한 이용재적을 나타내는 원목이용율 추정식이었으며, 이 두가지 추정식의 곱으로 조재율을 도출하였다. 흉고직경에 의한 목질부 재적율(W)은 $W=\frac{a_1}{1+a_2/D}+\frac{b_1}{1+b_2/D}$의 모형을 이용하였으며, 이 식의 적합도는 수종별로 99% 이상이었고 기타 검정통계량도 식의 적합성을 충분히 설명하고 있었다. 목질부 재적에 대한 원목이용율(M)은 $M=e^{a_1\(\frac{d}{D}\)^{a_2}}-(b_0+b_1D+b_2D^2+b_3D^3)$ 모형을 적용시켜 적합도는 수종별로 96% 이상이었다. 이 두가지 추정식을 이용하여 5개 수종별로 상업적 재적이용율인 조재율을 산정하고 조재율표를 작성하였다. 분석결과, 조재율은 침엽수와 활엽수 임상별로는 거의 차이가 없는 것으로 나타났으나, 기존 침엽수, 활엽수 조재율과의 차이는 있는 것으로 나타났다.

• 상하수도학회지
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• 제35권3호
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• pp.197-204
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• 2021

In MBR, extracellular polymeric substance (EPS) is known as an important factor of fouling; soluble EPS (sEPS) affects internal contamination of membrane, and bound EPS (bEPS) affects the formation of the cake layer. The production of EPS changes according to the composition of influent, which affects fouling characteristics. Therefore, in this study, the effects of the F/M ratio on the sEPS concentration, bEPS content, and fouling were evaluated. The effects of F/M ratio on the amount and composition of EPS were confirmed by setting conditions that were very low or higher than the general F/M ratio of MBR, and the fouling occurrence characteristics were evaluated by filtration resistance distribution. As a result, it was found that the sEPS increased significantly with the increase of the F/M ratio. When the substrate was depleted, bEPS content decreased because bEPS was hydrolyzed into BAP and seemed to be used as a substrate. In contrast, when the substrate is sufficient, UAP (utilization-associated products) was rapidly generated in proportion with the consumption of the substrate. UAP has a relatively higher Protein/Carbohydrate ratio (P/C ratio) than BAP, and this means, it has a higher adhesive force to the membrane surface. As a result, UAP seems like causing fouling rather than BAP (biomass-associated products). Therefore, R_f (Resistance of internal contamination) increased rapidly with the increase of UAP, and R_c (Resistance of cake layer) increased with the accumulation of bEPS in proportion, and as a result, the fouling interval was shortened. According to this study, a high F/M ratio leads to an increment in UAP generation and accumulation of bEPS, and by these UAP and bEPS, membrane fouling is promoted.

• 한국유기농업학회지
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• 제30권4호
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• pp.471-483
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• 2022

This study analyzed management situations of two organizations that have produced environment-friendly agricultural and processed meat products. 'A' farming corporation sells environment-friendly agricultural products like as grains, vegetables, fruits and processing foods. 'B' agricultural corporation processes and sells environment-friendly processed meat products, specially organic and antibiotic-free beef products. Recently, members and production areas of 'A' farming corporation have decreased because of their aging and labor shortage. And Indices for the management analysis are stability ratio, activity ratio and profitability ratio. Stability ratio indices are debt ratio, net worth ratio, fixed ratio and current ratio. Activity ratio ones include fixed assets turnover and net worth turnover. And profitability ratio is showed through return on investment, net return on sales and return on equity.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 춘계 학술발표회 제20권1호
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• pp.369-372
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• 2008

본 연구는 프리믹스 시멘트를 사용한 고강도 콘크리트의 참고배합 제안에 관련한 것으로서 W/B변화에 따른 고강도 콘크리트의 기초적 특성을 분석하였다. 실험결과 목표 슬럼프 플로우 및 목표 공기량 확보를 위한 고성능감수제 및 AE제의 사용량은 W/B가 증가할수록 감소하는 것으로 나타났고, W/B 변화에 따른 응결시간은 W/B 20%를 제외한 여타의 배합의 경우 W/B가 커질 수록 지연되는 것으로 나타났다. W/B 변화에 따른 압축강도는 W/B가 증가할 수록 저하하였고, 목표 슬럼프플로우 변화에 따라서는 큰 차이가 없는 것으로 나타났다. 한편, B/W와 압축강도의 관계를 회귀식으로 나타낸 결과 상관계수 0.9646으로 높게 나타나 실제 실무 활용이 가능할 것으로 판단된다.

• 전자공학회논문지A
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• 제33A권7호
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• pp.1-14
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• 1996

Effects of the external optical feedback on the optical transmission characteristics were evaluated for 3 kinds of commercialized DFB-LD modules for 2.5Gbps optical communication systems. As a result, intensity noise induced by external optical feedback via generating the external cavity modes deteriorated the transmission performances of sthe DFB-LD modules as much as 1.5dB, 1.2dB, and 1.0dB for the maximum feedback ratio of -8.8dB which corresponds to the worst reflection along the fiber transmission line. Additional penalty of 0.5dB was occurrred when state of polarization of feedback light was adjusted. From the experiments evaluating the isolation ratio of the single polarization optical isolator, decrease of the polarization dependent isolation ratio as much as 10dB from that of specification and the effective isolation ratio as much as 20dB from that of specification was mjor cause of high sensitivity of DFB-LD modules to external feedback. It was suggested that polarization independent optical isolator or single polarization optical isolator with isolation ratio specification of more than 40dB is required for 2.5Gbps DFB-LD modules with complete suppression of external feedback effects.

• Journal of electromagnetic engineering and science
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• 제12권4호
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• pp.247-253
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• 2012

This study presents a new, simple method for improving the front-to-back (F/B) ratio of a microstrip patch antenna. The back radiation of the microstrip patch antenna is reduced by removing some metallic parts around the ground plane and placing a new soft-surface configuration, consisting of an array of stand-up split-ring resonators on a bare dielectric substrate near the two ground plane edges. Compared to the F/B ratio of a conventional microstrip patch antenna with a full ground plane of the same size, our proposed microstrip patch antenna experimentally achieves an improved F/B ratio of 9.6 dB.

• 동아시아식생활학회지
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• 제15권5
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• pp.582-590
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• 2005

The application of consomme prepared with different ratios of ground beef and ground chicken to improve taste preferences and the cost of foodstuffs was attempted by reviewing fundamental data and the effect on the sensory and physical characteristics of treatment These treatments were prepared with different ratios(9:1(A), 7:3(B), 5:5(C), 3:7(D), 1:9(E) w/w) of ground beef and ground chicken, respectively. Sensory properties were evaluated in the aspects of both acceptability and intensity. From the acceptability aspect, A treatment showed the highest scores in smell, B in mouthfeel and taste, A and B in color and overall acceptability, respectively. In terms of acceptability, B treatment was favored most for color, mouthfeel, taste and overall acceptability except smell. The more the ground chicken, the higher the intensity aspect E treatment showed higher values than A in all the intensity aspects. Moisture contents and crude proteins increased by increasing the mixed ratio of ground beef, whereas crude ash, solid matter and pH increased by increasing the mixed ratio of ground chicken. Tumidity values were the highest in E treatment, whereas the lowest in A. Tumidity values were increased significantly by increasing the mixed ratio of ground chicken. Viscosity increased by increasing the mixed ratio of ground chicken. The highest viscosity was shown in E treatment The colorimetric lightness values(L) decreased and redness(a), yellowness(b) and total color difference values(AE) increased significantly by increasing the mixed ratio of ground chicken. This experimental study showed that A and B treatment had the highest values in overall acceptability. The results of analysis in crude protein, solid matter, tumidity and viscosity were increased by increasing the mixed ratio of ground chicken. B treatment prepared with a ratio of 7:3 of ground beef and chicken had the most favorable sensory quality. These results suggested the basic information to improve acceptability and to save the costs of Consomme recipes for foodservice institutions.

• 한국병원경영학회지
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• 제17권1호
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• pp.79-112
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• 2012

The purpose of this study is to examine the differences of profitability based on the analysis of business and medical service performances of four hospitals in Incheon area with similar size. and to compare hospitals with the best and the worst performances and analyze the factors behind the differences. The differences could be caused by differences in medical service statistics, number of staff, and financial results, etc. The data was acquired through the homepage of the National Tax Service(financial statements for the fiscal year 2009) and the Medical Record Association of Incheon(medical service statistics for the years 2008 and 2009) along with questionnaire survey to the hospitals(personnel data for the year 2009). The results of the study are as follows. Medical profits to medical revenues ratio for the hospitals(referred as Hospital A, B, C, and D) shows, in order, C(8.2%), A(8.0%), B(7.8%), and D(7.4%). However, net income to medical revenues ratio shows otherwise: C(8.5%), D(5.8%), A(3.0%), and B(0.6%). Hospital B shows a high medical profit to revenue ratio but the lowest net income to revenue ratio due to large interest expenses. The leverage ratio of Hospital B is the highest (419.6%), resulting in a very low interest coverage ratio(1.1). On the other hand, Hospital C shows favorable results in both profit ratios, with 8.2% and 8.5% each. Hospital C has the lowest leverage ratio(53.0%) and the highest interest coverage ratio(34.9). Therefore, the results show Hospital C has the best performance while Hospital B the worst. The two hospitals(B and C) show similar results in certain areas and big differences in other areas. The area that has the biggest influence on financial results turns out leverage ratio. Hospital B shows 'very good' to 'good' results in terms of medical service statistics in general. However, the leverage ratio is too high and the liquidity ratio too low, resulting in a very low profit ratio. The results of this study have some limitations in terms of generalization as only four hospitals in Incheon area were selected for the study, resulting in a deficiency in the representativeness of the sample. Further studies with bigger sample size and deeper analysis are expected in this area.

• 한국농공학회지
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• 제34권1호
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• pp.78-86
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• 1992

This paper aims at investigating the effect of steel ratio and the magnitude of edge-ratio on the mechanical characteristics of reinforced concrete ring sector plate. The influence of steel bars was taken into account by coupling stiffness matrix of the steel bar element with that of the concrete plate element without dealing with separate element of steel bar and by establishing the composite stiffness matrix, which leads to the desirable result which does not increase th number of element could be obtained. Through case studies with 6 cases various steel ratios in ring sector plate supported at four edges and 4 cases with different open angles, the influence of the steel ratio was examined. A numerical analysis to find out the effect of the steel ratio d ue to above mentioned cases was carried out by 4 boundary conditions ; all edges clamped (B.C-1), all edges simply supported (B.C-2), curvilinear two edges clamped and other edges free (B.C-3) and curvilinear two edges simply supported and other edges free(B.C-4). The main results obtained are summarized as follows : 1. The effect of steel ratio on the magnitude of lateral deflection and x-directional bending moment at the center of sector plate and the midpoint of outer and inner curvilinear edges is almost the same up to $30^{\circ}$ of open angle. Beyond $30^{\circ}$ of the angle, the larger the angle, the greater the effect of ratio. 2. In design works using balanced steel ratio, the effect of steel bar can be ignored. But for larger open angles, especially greater than $90^{\circ}$, it proves desirable to consider the effect of steel bar. 3. The effect of the arc length of center circle/straight edge on lateral deflection and bending moment is remarkable in B.C-2. For larger open angle, the effect is also noted except for B.C-3 which turn out hardly affected. 4. The effect of the radius of curvature/straight side length on lateral deflection and x-directional bending moment is noted in B.C-2. As open angle increases, B.C-1 and B.C-3 almost agree and B.C-2 approaches B.C-4.

• 한국통신학회논문지
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• 제36권3A호
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• pp.296-301
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• 2011

GPS(Global Positioning System)서비스는 다 우선서비스보다 중요성을 갖는 서비스로 분류 된다. 따라서, GPS는 간섭신호로부터 보호할 필요가 있으며 이에 본 논문에서는 비트에러율(BER)을 근거로 GPS의 보호비를 제안하였다. 도출된 최대허용 간섭신호는 -190 dBm/Hz이며 간섭신호 대 잡음비(I/N)값은 -16 dB이다. 도출된 GPS 보호비(I/N)는 GPS의 실제 운용마진을 4 dB로 고려할 경우 -20 dB로 요구된다. 분석결과는 향후 안정적인 GPS 서비스 운용을 위한 국내 GPS 보호기준 제정에 도움을 줄 것으로 기대된다.