• 한국산림과학회지
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• 제94권2호통권159호
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• pp.82-89
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• 2005

The purpose of this paper is to investigate index numbers by conducting various comparisons among the widely used index formulas. The comparison is considered in three ways; 1) divergences in the magnitudes of index numbers due to the use of different formulas (Laspeyres, Paasche, Fisher, and Tornqvist); 2) the effect of selection of base year (fixed-year base vs. chain-type); 3) the degree of approximation of indirect to direct quantity index. The empirical application is to sawmills and planing mills industry of U.S. using a national time series data covering years of 1948-2000. The results show that the differences between Laspeyres and Paasche index can be substantial in some cases while the difference between Fisher and Tornqvist index is minimal. We also confirm that the selection of base year can cause significant divergences, especially when the variables undergo rapid price or quantity changes over time. We find that indirect quantity index approximates direct quantity index reasonably well in U.S. sawmill industry.

• 충청수학회지
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• 제20권3호
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• pp.231-243
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• 2007

In this paper, we study a Lotka-Volterra type simple food chain model. We investigate the positive coexistence of the steady states to the model and give some results for the extinction of species under certain assumptions which can be interpreted as Domino effect and Biological control. The methods of a decoupling operator and the fixed point index theory on a positive cone are used as well as the comparison argument. Numerical evidences for our results also are provided.

• Preventive Nutrition and Food Science
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• 제16권4호
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• pp.339-347
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• 2011

Flour and isolated starch from chickpea (desi type, 328S-8) were evaluated for their in vitro digestibility and physicochemical properties. The protein content, total starch content and apparent amylose content of chickpea flour and isolated starch were 22.2% and 0.6%, 45.8% and 91.5%, and 11.7% and 35.4%, respectively. Chickpea starch granules had an oval to round shape with a smooth surface. The X-ray diffraction pattern of chickpea starch was of the C-type and relative crystallinity was 24.6%. Chickpea starch had only a single endothermic transition (13.3 J/g) in the DSC thermogram, whereas chickpea flour showed two separate endothermic transitions corresponding to starch gelatinization (5.1 J/g) and disruption of the amylose-lipid complex (0.7 J/g). The chickpea flour had a significantly lower pasting viscosity without breakdown due to low starch content and interference of other components. The chickpea starch exhibited significant high setback in the viscogram. The average branch chain length, proportion of short branch chain (DP 6~12), and long branch chains (DP${\geq}$37) of isolated chickpea starch were 20.1, 20.9% and 9.2%, respectively. The rapidly digestible starch (RDS), slowly digestible starch (SDS) and resistant starch (RS) contents of chickpea flour and starch were 9.9% and 21.5%, 28.7% and 57.7%, and 7.1% and 9.3%, respectively. The expected glycemic index (eGI) of chickpea flour (39.5), based on the hydrolysis index, was substantially lower than that of isolated chickpea starch (69.2).

• 한국데이터정보과학회:학술대회논문집
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• 한국데이터정보과학회 2005년도 춘계학술대회
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• pp.83-126
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• 2005

Single-index models have found applications in econometrics and biometrics, where multidimensional regression models are often encountered. Here we propose a nonparametric estimation approach that combines wavelet methods for non-equispaced designs with Bayesian models. We consider a wavelet series expansion of the unknown regression function and set prior distributions for the wavelet coefficients and the other model parameters. To ensure model identifiability, the direction parameter is represented via its polar coordinates. We employ ad hoc hierarchical mixture priors that perform shrinkage on wavelet coefficients and use Markov chain Monte Carlo methods for a posteriori inference. We investigate an independence-type Metropolis-Hastings algorithm to produce samples for the direction parameter. Our method leads to simultaneous estimates of the link function and of the index parameters. We present results on both simulated and real data, where we look at comparisons with other methods.

• 한국정밀공학회지
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• 제22권11호
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• pp.72-81
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• 2005

A new spherical-type 3-degree-of-freedom parallel mechanism consisting of a two degree-of-freedom parallel module and a serial module is proposed. Two alternative designs for the serial sub-chain are suggested and compared. The first design employs RU joint arrangement for the serial sub chain structure. The second design incorporates a gear chain to drive the distal revolute joint of the serial sub-chain from the base platform of the mechanism. This modification significantly improves kinematic characteristics of the mechanism within its workspace. Firstly, the closed-form solutions of both the forward and the reverse position analysis are derived. Secondly, the first-order kinematic model with respect to three inputs which are located at the base is derived. Thirdly, it is confirmed through simulation that the modified mechanism has much more improved isotropic characteristic throughout the workspace of the mechanism. Lastly, the proposed mechanism is implemented to verify the results from this analysis.

• 대한교통학회지
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• 제26권5호
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• pp.7-16
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• 2008

본 연구는 그동안 여객보다 상대적으로 소홀히 되어온 화물통행의 행태분석을 통행사슬관점에서 분석하였다. 화물자동차 통행분석에 대한 운행특성 지표들은 공간 및 통행패턴별로 설명되지 못하였음을 지적하고, 2005년 수행된 제3차 전국물류현황조사 자료를 이용하여 실증분석 하였다. 전체 분석대상 화물자동차는 약 13,000대 이었으며 화물자동차의 통행일지 자료를 도면위에 맵핑을 통하여 통행사슬을 새롭게 분류하였다. 또한 약 13,000대의 화물자동차에 대한 물리적 특성지표 및 운행효율성지표를 산정하고 앞서 정의한 통행사슬과 연관지어 분석하였다. 분석 결과 영업용 화물자동차가 자가용 화물자동차보다 다소 우위에 있는 것으로 분석되었다. 물리적 지표에서 공간적으로 볼 때, 도시내와 광역권은 비슷하고 지역간은 통행거리와 통행시간이 길게 나타남을 알 수 있다. 운행효율성 지표는 지역간, 지역내 및 광역 권에서 자가용 화물자동차보다 영업용 화물자동차의 효율성이 약간 높은 것인 것으로 분석되었나 단순 왕복 및 복잡정도에 따라서는 큰 차이가 없음을 알 수 있었다. 영업용 화물자동차의 경우, 적재능력이 높을수록 효율성이 높게 나타남을 알 수 있었다.

• 대한의생명과학회지
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• 제13권4호
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• pp.293-304
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• 2007

The emergence of extended spectrum $\beta$-lactamase (ESBL) producing bacteria is worldwide concern. Until recently, the most frequently identified strains in the Republic of Korea were E. coli and Klebsiella spp. The incidence of resistance to extended spectrum $\beta$-lactam antibiotics is increasing in Wonju city, Korea. Total 57 strains of ESBL producing E. coli and Klebsiella species were isolated from Wonju Christian Hospital during a 9 month-period from April to December, 2003. To determine the prevalence and genotypes of the ESBL producing clinical isolates, antibiotic susceptibility and ESBL activity test by VITEK system and double disk synergy (DDS) test, and PCR based genotyping were performed. Fourteen (82%) isolates of 17 ESBL producing E. coli were found to have $bla_{TEM}$ gene and 5 (29%) isolates were found to have $bla_{CTX-M}$ gene by polymerase chain reaction (PCR). Thirty (75%) isolates of 40 ESBL producing Klebsiella species with $bla_{TEM}$ gene, 38 (95%) isolates with $bla_{SHV}$ gene, and 7 (20%) isolates with $bla_{CTX-M}$ type gene were also identified. Enterobacterial repetitive intergenic consensus (ERIC) PCR and similarity index by dendrogram for genetical similarity to band pattern of each clinical isolates were examined. ESBL producing E. coli were grouped into 6 clusters up to 84% of similarity index and Klebsiella species were grouped into 12 clusters up to 76% of similarity index. In conclusion, ESBL producing clinical isolates were characterized with the results from antimicrobial resistance pattern and genetical similarity using ERiC PCR.

• 한국구조물진단유지관리공학회 논문집
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• 제20권2호
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• pp.60-66
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• 2016

본 연구는 실리콘계 정포제의 특성에 따른 폴리우레탄 폼 지수제의 cell 구조와 흡수량 변화를 알아보기 위하여 6종의 정포제를 사용하여 폴리우레탄 폼 지수제를 제조하여 FE-SEM으로 분석한 결과 실리콘 정포제의 실록산 주사슬 말단에 PO n개가 결합되어 있는 DC-193, DC-2585, DC-5125, DC-198의 cell 구조는 close cell로 확인이 되었고, 실리콘 정포제의 실록산 주사슬 말단에 EO n개가 결합 되어 있는 DC-5043과 DC-5598은 open cell 구조로 나타났다. 또한 cell 구조 변화에 따른 흡수량 에서는 close cell의 크기가 가장 세밀하고 균일한 DC-193의 흡수량이 가장 적게 나타나 내수성이 가장 우수한 것으로 나타났으며 open cell의 크기가 가장 크게 형성된 DC-5043의 흡수량이 가장 많은 것으로 나타났다. 이들의 방수성능을 콘크리트 구조물을 모사하여 시험한 결과 누수가 없음을 확인하였다.

• Journal of Periodontal and Implant Science
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• 제35권1호
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• pp.43-52
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• 2005

This study was performed to evaluate the relation between the interval of supportive periodontal therapy and the prevalence of the subgingival microflora. The subgingival plaques from 108 patients were used in the study. Control group were the patients with no periodontal treatment and test groups were assigned into 3 groups according to the period of recall check: group 1; 1-2 months, group 2; 3-4 months, group 3; 6months or more. The polymerase chain reaction (PCR) used for direct identification of periodontal pathogens (P. gingivalis, T. forsythensis, T. denticola) in subgingival plaque. The results of this study were as follows. 1. The prevalence of P. gingivalis, T. forsythensis, T. denticola in control group were 100%, 87%, 90%. 2. In clinical parameters such as plaque index, gingival index, bleeding on probing, control group was not significant different with group 1 but Significant different with group 2, group 3. 3. In group 1, the majority of P. gingivalis had type II fimA. 4. When group 3 were compared with group 1, the prevalence of P. gingivalis increased. But the prevalence of P. gingivalis with type II fimA, which have the virulence factor, decreased. 5. We were unable to find the correlation between P. gingivalis with type IV fimA and periodontal disease. 6. The prevalence of T. forsythensis, T. denticola in test group were 85%, 93% or more. From the above results, we were able to find the relation between the interval of supportive periodontal therapy and the prevalence of the subgingival microflora and the need of the strict supportive periodontal therapy to prevent recurrence of periodontal disease, because there were high prevalence of periodontal pathogens.

• 대한화학회지
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• 제55권4호
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• pp.673-679
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• 2011

지글러-나타 촉매를 사용하여 에틸렌을 중합함으로써 다양한 공단량체의 종류와 조성을 갖는 이중 분자량 분포의 고밀도 폴리에틸렌이 합성되었다. 이들의 구조와 물성을 GPC, NMR, DSC, 인장 측정기를 이용하여 연구하였다. 에틸렌/1-헥센 공중합체가 에틸렌/1-부텐 공중합체보다 비슷한 조성을 가질 경우 높은 인장강도와 파단연신율을 가짐을 확인 하였다. 분자량은 고분자의 공단량체 비율이 증가할수록 감소하였다. 짧은 곁사슬은 결정화도에 영향을 주어 결과적으로 이중 분자량 분포를 갖는 고밀도 폴리에틸렌의 모폴로지와 기계적 물성에 영향을 미쳤다. SSA로 처리 후 다수의 발열 곡선이 관찰되었으며 이는 주로 에틸렌 배열길이와 라멜라 두께의 불균일성에 기인한다. 분포지수의 차이로부터 공단량체의 조성이 높은 폴리에틸렌의 SCB 분포가 균일도를 향상시킴을 알 수 있었다.