복합 분위수 회귀에 대한 붓스트랩 방법의 응용

서강민,방성완,전명식,Seo, Kang-Min,Bang, Sung-Wan,Jhun, Myoung-Shic 한국통계학회 2012 응용통계연구 Vol.25 No.2

선형 회귀모형에서 오차항들이 서로 독립이고 동일한 분포를 따른다고 가정할 경우, (회귀계수의 강건한 추정을 위하여) 모든 분위수 함수의 회귀계수가 동일한 값을 갖는다는 사실에 근거한 복합 분위수 회귀(composite quantile regression) 방법을 고려할 수 있다. 본 논문에서는 복합 분위수 회귀에서 사용되는 분위수의 개수를 선택하기 위해 붓스트랩 방법의 가능성을 검토하였다. 또한, 분위수 회귀와 복합 분위수 회귀의 성능을 비교하기 위해 붓스트랩 방법을 이용하여 신뢰구간을 구축하고, 이들의 포함확률과 평균길이를 비교하였다. 이러한 모의실험을 통하여 복합 분위수 회귀의 우월성과 통계적 추론에 있어서 붓스트랩 방법의 유용성을 확인하였다. Composite quantile regression model is considered for iid error case. Since the regression coefficients are the same across different quantiles, composite quantile regression can be used to combine the strength across multiple quantile regression models. For the composite quantile regression, bootstrap method is examined for statistical inference including the selection of the number of quantiles and confidence intervals for the regression coefficients. Feasibility of the bootstrap method is demonstrated through a simulation study.

체외 소화과정 동안 Gastric lipase의 첨가가 반려견 사료의 소화율에 미치는 영향

서강민,조현우,김기현,이민영,전중환,김찬호,임세진,정소희,양가영,천주란 경상대학교 농업생명과학연구원 2023 농업생명과학연구 Vol.57 No.3

본 연구는 위장 단계의 소화과정에 관여하는 Gastric lipase (GL)를 반려견을 위한 정적 체외 소화모델(Static in vitro digestion model)에 적용을 검토하기 위하여 실시되었다. GL의 첨가가 체외 소화과정 동안 건물(Dry matter; DM), 조단백질(Crude protein; CP) 그리고 조지방(Ether extracts; EE) 소화율에 미치는 영향을 평가하였다. GL은 위장 소화단계에서 첨가되었다. 위장(39℃, 2 hr.)과 소장(39℃, 4 hr.) 소화 후에 비소화 분획을 분리하였다. 그리고 실험사료와 분리된 비소화 분획에서 DM, CP 그리고 EE 수준을 측정하고 각각의 소화율을 계산하였다. 위장과 소장 소화단계에서 측정된 DM, CP 그리고 EE 소화율은 Control과 GL 그룹 사이에서 통계적으로 유의한 차이는 관찰되지 않았다(p>0.05). 결과적으로 우리의 체외 소화모델에서 GL의 첨가는 DM, CP 그리고 EE의 소화율에는 영향을 미치지 않는 것으로 나타났다. 따라서 이와 같은 결과는 정적 체외 소화모델을 이용한 소화율의 평가에 있어서 GL의 역할은 다소 제한적일 수 있다는 것을 시사한다. The effect of gastric lipase (GL) on the digestibility of dry matter (DM), crude protein (CP) and ether extracts (EE) was investigated during in vitro digestion as a process to optimize the condition of a static in vitro digestion model for dogs. GL was added during the gastric phase of in vitro digestion. After gastric (39℃, 2 hr.) and intestinal (39℃, 4 hr.) digestion phases, the non-digested fraction was collected from the final reactant DM, CP, and EE levels in the non-digestible fraction were analyzed and those of the digestibility was calculated. DM, CP and EE digestibility at gastric and intestinal digestion phases were not significantly different between the Control and GL groups (p>0.05). As a result, in the static in vitro digestion model, the addition of GL did not affect the digestibility of DM, CP and EE. Therefore, these results suggest that the role of GL in the evaluation of digestibility of dog`s food using a static in vitro digestion model are limited.

비글견의 BCS별 필수 미네랄의 외관상 전장 소화율 평가

서강민,조현우,이민영,천주란,김기현 경상국립대학교 농업생명과학연구원 2023 농업생명과학연구 Vol.57 No.4

This study was conducted to evaluate the differences in mineral digestibility between overweight and normal weight beagle dogs. A total of 11 healthy neutered beagle dogs (47.7±0.14 month-age old) were divided into the Normal BCS Group (BCS≤5, n=5) andthe High BCS Group (BCS ≥6, n=6) based on their body condition scores (BCS). The experimental diet was manufactured to meetthe nutrient requirements and supplied to dogs according to their individual energy requirement amount twice a day for 14 days. Theapparent total tract digestibility of minerals was evaluated as an indicator method using 0.5% chromium oxide (Cr2O3). The contentsof macro- (K, Mg, P, Na, Ca) and micro-minerals (Se, Fe, Zn, Cu, Mn) in diet and feces were analyzed using an inductively coupledplasma spectrophotometer. Body weight and BCS were significantly higher in the High BCS group than in the Normal BCS group(p<0.01), and no statistically significant changes were observed in the weight and BCS within same group during the experimental period(p>0.05). As a result of evaluating mineral digestibility, the digestibility of magnesium, phosphorus, and calcium among macro mineralstended to be high in the High BCS group (p<0.1). And the digestibility of manganese among micro minerals was significantly higherin the High BCS group (p<0.05), and the digestibility of selenium and zinc showed a high tendency (p<0.1). In addition, regardless of statistical significance, the High BCS group showed a higher digestibility than the Normal BCS group in overall minerals analyzedin this study. The results of this study showed that overweight or obesity has the potential to induce changes in mineral digestibilityin beagle dogs. 본 연구는 과체중과 정상체중의 비글견 사이에서 미네랄 소화율의 차이를 평가하기 위해 수행되었다. 중성화 된 건강한 비글견 11마리(47.7개월령±0.14)의 Body condition score (BCS)를 기준으로 Normal BCS 그룹(BCS≤5, n=5)과 High BCS 그룹(BCS ≥6, n=6)의 두 그룹에 배치하였다. 시험사료는 반려견의 영양소 요구량을 충족하도록 제조하여 개체 별 에너지요구량에 맞춰 일일 2회에 나누어 14일 동안 급여하였다. 미네랄의외관상 전장 소화율은 0.5% 산화크롬(Cr2O3)을 이용한 지시제법을 이용하여 평가되었다. 사료와 분변 내 Macro 미네랄(K, Mg, P, Na, Ca)과Micro 미네랄(Se, Fe, Zn, Cu, Mn)의 함량은 유도결합플라즈마 분광광도계를 이용하여 분석하였다. 체중과 BCS는 Normal BCS 그룹 보다High BCS 그룹이 유의하게 높았으며(p<0.01), 시험기간 동안 두 그룹 내 각각의 체중과 BCS는 통계적으로 유의한 변화는 관찰되지 않았다(p>0.05). 미네랄 소화율을 평가한 결과, Macro 미네랄 중에서는 마그네슘, 인, 칼슘의 소화율이 High BCS 그룹에서 높은 경향으로 관찰되었으며(p<0.1),Micro 미네랄 중에서는 High BCS 그룹에서 망간의 소화율이 유의하게 높았고(p<0.05), 셀레늄과 아연의 소화율은 높은 경향(p<0.1)을 나타내었다. 또한, 통계적인 유의성과 관계없이 분석한 모든 미네랄 지표에서 High BCS 그룹이 Normal BCS 그룹보다 높은 소화율의 결과를 보여 주었다. 본 연구의 결과는 비글견에서 과체중 또는 비만이 미네랄 소화율의 변화를 유도할 잠재적 가능성을 보여주었다.

Prediction of apparent total tract digestion of crude protein in adult dogs

서강민,Hyun-Woo Cho,Min Young Lee,Chan Ho Kim,Ki-Hyun Kim,천주란 한국축산학회 2024 한국축산학회지 Vol.66 No.2

To predict the apparent total tract digestibility (ATTD) of crude protein (CP) in dogs we developed an in vitro system using an in vitro digestion method and a statistical analysis. The experimental diets used chicken meat powder as the protein source, with CP levels of 20% (22.01%, analyzed CP value as dry-based), 30% (31.35%, analyzed CP value as dry-based), and 40% (41.34%, analyzed CP value as dry-based). To simulate in vivo digestive processes a static in vitro digestion was performed in two steps; stomach and small intestine. To analyze ATTD the total fecal samples were collected in eight neutered beagle dogs during the experimental period. CP digestibility was calculated by measuring CP levels in dog food, in vitro undigested fraction, and dog feces. In result, CP digestibility at both in vivo and in vitro was increased with increasing dietary CP levels. To estimate in vivo digestibility the co-relation of in vivo ATTD and in vitro digestibility was investigated statistically and a regression equation was developed to predict the CP ATTD (% = 2.5405 × in vitro CP digestibility (%) + 151.8). The regression equation was evaluated its feasibility by using a commercial diet. The predicted CP digestibility which was calculated by the regression equation showed high index of similarity (100.16%) with that of in vivo in dogs. With that, it would be a feasible non-animal method to predict in vivo CP digestibility by using in vitro digestion method and the proposed linear regression equation in adult dogs.

기능교정이 Cervical Kyphosis와 Postural Balance에 미치는 효과

서강민 동방문화대학원대학교 자연치유연구소 2018 자연치유연구 Vol.3 No.1

This study selected on the subjects of this study the twelve subjects who had a Cobb’s angle less than 35°or Jochumsen’s depth less than 3 mm after cervical plain X-ray, and was conducted to analyze the effect of functional adjustment procedure on cervical kyphosis and postural balance. To achieve the purpose of the study, with one-group pre-test and post-test experiment design, twenty-minute sessions of functional orthodontic treatment were given to the participants for 8 weeks. Pre-treatment counseling, cervical lateral view X-ray, and Exbody 720 body image analyzer were used for preliminary examination, and the right side of the body was photographed. After the functional adjustment procedure, the right side of the body was photographed using a lateral view X-ray and an Exbody 720 body type analyzer. The collected data were analyzed using SPSS 18.0. and the results of the study are summarized as follows. First, a corresponding sample t-test was performed to statistically validate the effect of functional adjustment procedure of Jochumsen`s depth and Cobb’s angle of curvature of the study participants. The t-test was pre- and post-categorical, and the significance level was measured at the 95% confidence level. The results showed that there was a statistically significant difference (p<.05) in the pre- and postdisplacement of the posterior curved Jochumsen`s depth. There was also a significant difference (p<.05) in the pre- and post-displacement of the effect of functional adjustment procedure on Cobb’s angle. Second, a response sample t-test was performed to statistically validate the effect of functional adjustment procedure on postural balance of study participants. The t-test was pre- and post-categorical, and the significance level was measured at the 95% confidence level. The results of the analysis showed that the pre- and post-displacement of the knee flexion angle, pelvic tilt angle, tilt angle of the ear canal at the center of the humerus, and LOH were statistically significant (p<.05). On the other hand, there was no significant difference in the postoperative displacement of the functional correction effect on the central angle of the humerus in the iliac crest nodule. Through the empirical analysis, this study showed that after the functional orthodontic treatment, the cervical kyphosis and postural balance were improved, and it was confirmed that there was a positive effect of the alternative medicine on posture and postural balance. In addition, functional orthodontic treatment is expected to contribute to improvement of physical therapy and quality of life of pathological disorder, and it will play a mediating role in preventing the secondary disease by achieving the physical balance of modern people, which will be a great help for daily life.

Cysteamine hydrochloride (CSH)의 첨가 급여가 육용계의 생산성과 소화율에 미치는 영향

서강민(Kangmin Seo),천주란(Ju Lan Chun),김기현(Ki Hyun Kim),남기택(Ki-Taeg Nam) 한국산학기술학회 2021 한국산학기술학회논문지 Vol.22 No.5

본 연구는 Cysteamine hydrochloride (CSH)의 사료 내 첨가 급여가 육용계의 생산성 및 소화율에 미치는 영향을 조사하기 위해 수행되었다. 1 일령의 Ross broiler 수컷 180 수를 공시하여 3 개의 실험그룹에 각각 3 반복으로 반복 당 20 수씩 배치하였다. 실험설계는 Control (Basal diets), CSH-1 (Basal diets+250 ㎎ CSH/㎏ feed), CSH-2 (Basal diets+500 ㎎ CSH/㎏ feed)으로 디자인하였다. 육성 초기 동안의 일당 사료섭취량, 체중, 일당 증체량, 사료요구율, 육성률은 모든 실험그룹들 사이에서 차이가 나타나지 않았다. 육성 후기와 전체 실험기간 동안의 결과를 종합적으로 평가한 경우, CSH-1과 CSH-2 그룹은 Control 그룹과 비교하여 사료요구율이 유의하게 개선되는 것으로 나타났다(p <0.05). 한편, CSH의 사료 내 첨가는 육용계에 있어서 도체율과 정육률(가슴근육, 다리근육)에는 영향을 미치지 않는 것으로 나타났다. 유기물의 소화율은 CSH-2 그룹이 대조구에 비하여 높은 경향으로 나타났으나, 통계적인 유의차는 인정되지 않았다(p <0.1). 본 연구의 결과는 사료 내 250-500 ㎎/㎏의 CSH 첨가 급여는 육용계의 사료요구율 및 유기물소화율을 개선시킬 수 있음을 시사한다. This study investigated the effect of dietary supplementation with cysteamine hydrochloride (CSH) on the growth performance and nutrient digestibility of broilers. A total of 180 one-day-old male Ross broilers were allotted to one of the three treatment groups with three replications (20 birds per replication). The experimental groups were as follows: control group (basal diet), CSH-1 group (basal diet + 250 ㎎ CSH/㎏ feed), and CSH-2 group (basal diet + 500 ㎎ CSH/㎏ feed). During the grower period, feed intake, body weight, average daily gain, feed conversion ratio (FCR), and livability did not show any variation among the treatment groups. On the other hand, a comprehensive evaluation of the finisher period and the entire experiment period found that FCR was significantly improved in CSH-1 and CSH-2 groups as compared to the control group (p <0.05). The dietary supplementation of CSH did not affect the carcass and meat percent (breast and leg muscle). Although there was no significant difference, the digestibility of organic matter tended to be higher in the CSH-2 group than in the control group (p <0.1). This study suggests that a dietary supplement with 250-500 ㎎/㎏ CSH can be effective in improving FCR and the digestibility of organic matter in broilers.

AHP 기법을 활용한 친환경 군 차량 선정기준 개발

권강민,서선덕,정병호 한국교통연구원 2010 交通硏究 Vol.17 No.2

Due to the national greenhouse gas reduction obligations(The Kyoto protocol Ⅱ), the south korea is promoting the various policy measures widely such as the green-growth policy, including the development of green-car. Therefore, ultimately this study to meet the government's green-growth policy, explores the direction of green-car application in the military. Three alternatives such as hydrogen fuel cells, hydrogen internal combustion engine hybrids and plug-in hybrid vehicles are analyzed by the AHP analysis techniques. The evaluation values are determined by the four kinds of operability in the military, economy, technology and safety. And total 30 military and civilian experts' AHP survey results were analyzed through the statistical package program. 한국은 향후 온실가스 의무 감축에 따른 경제적 추가 비용 및 산업 경쟁력 약화 등의 충격을 최소화하기 위해 ‘녹색성장’ 정책의 일환으로 친환경 그린카 개발을 신성장 동력 및 국가 전략 산업으로 육성하고 있다. 이와 더불어 2009년부터 군(軍)도 국방부 차관을 위원장으로 국방녹색추진위원회를 조직하여 적극적으로 친환경 패러다임에 동참하고 있다. 본 연구에서는 ‘녹색성장’ 정책과 더불어 중․단기적으로는 군에 하이브리드 차량을 적용하되, 장기적으로 실현 가능하고 전․평시 전투력을 저해하지 않는 범위 내에서 궁극적인 군(軍) 내 친환경 그린 차량 적용 방향에 대해 연구해 보고자 한다. 수소연료전지, 수소내연기관 하이브리드, 플러그인 하이브리드 차량의 3가지 분석 대안에 대해 AHP 기법을 적용하고, 평가 기준은 군 운용성, 경제성, 기술성, 안전성의 4가지로 결정하였으며, 의사 결정 집단은 최종적으로 군과 민간 전문 실무자 2개 그룹의 총 30명을 대상으로 분석하였다.

PLS트럭 및 표준 파렛트 규격 복수화 적용이 군수지원에 미치는 영향 연구

권강민,김민우,강성진,강경우,서선덕,Kwon, Kang-Min,Kim, Min-Woo,Kang, Seong-Jin,Kang, Kyung-Woo,Suh, Sun-Duck 한국국방경영분석학회 2009 한국국방경영분석학회지 Vol.35 No.2

최근 군(軍) 물류 분야에서 3PL(3rd Party Logistics), 4PL과 같은 아웃소싱이 중요한 아젠다로 부각되고 있다. 하지만, 3PL을 성급하게 군 물류 분야에 적용시, 전시 전투력 저하, 정보 보안 취약성, 3PL 업체의 재하청(Sub-contract)에 따른 질적 저하, 규모의 경제에 미달하는 군내 소랑 조달에 따른 원가 상승 압력 등의 부작용 우려가 있다. 최근 미국, 영국과 같은 선진국에서는 이런 부작용을 보완하고자, 민간 부문과의 상호 보완적 협력 관계를 통한 민 관 경쟁 위탁(private-public competitive sourcing) 개념이 발전하고 있다. 이 개념이 우리 군(軍) 물류 분야에 적용되기 위해서는 군과 민간이 합리적으로 경쟁할 수 있는 군 수송 분야의 재정비와 효율화가 선제적으로 요구된다. 따라서 이 연구는 군 물류 표준화 5개 분야중 수송 분야에 중점을 두어 파렛트 규격 복수화 방안 (T11,T12) 시행에 따른 PLS(Palletized Load System) 트럭 적용 개선 방안 및 모형을 제시한 후, 사단급 부대 사례 분석을 통하여 계량화된 개선 효과를 분석하였다. In the military logistics, the Outsourcing such as 3PL (3rd Party Logistics) and 4PL has emerged recently as an important agenda. However, when 3PL applied prematurely, side effects will occur such as the loss of combat power in wartime, the security vulnerabilities and the high cost by a small amount of military order. Recently, the developed countries such as the United States and the Britain want to compensate for these side effects. Therefore, They are developing the private-public competitive sourcing concept for the complementary partnership and the foster competition with the private sector. To apply this concept to the Korean Military, they need to be reorganized and promote the efficiency in the military logistics. Especially, the transportation sector. Therefore, this study, which is focused on the transportation sector, offers two kinds of measures to improve such as the Dual Pallet Standard (T11, T12) and the PLS(Palletized Loading System) truck system. Finally, these improvements will be analyzed by the simulation in this paper.

Evaluating sulfoxaflor residues in pig tissues using animal modeling

조현우,서강민,Jin Young Jeong,Ju Lan Chun,Ki Hyun Kim 한국축산학회 2022 한국축산학회지 Vol.64 No.5

Maximum residue limits (MRL) for pesticides in feed have been set to protect public healthand produce safe livestock products. In vivo experiments to establish MRL are essential,as livestock are commonly used to obtain reliable in vivo quantitative information. Here, weaimed to evaluate whether small laboratory animals can replace or reduce monogastric livestockin experiments to quantify pesticide residues in vivo after oral consumption throughfeed. First, 24 pigs and rats were randomly assigned to four groups and fed 0, 3, 9, or 30 mg/kg of sulfoxaflor. After four weeks, serum, muscle, fat, liver, kidney, and small intestine sampleswere collected, and sulfoxaflor residues were analyzed using liquid chromatography –tandem mass spectrometry. Sulfoxaflor residues in pig tissues were significantly correlatedwith those in rat tissues. Model equations were formulated based on the residual sulfoxafloramount in pig and rat tissues. The calculated and measured sulfoxaflor residues in pigs andrats showed more than 90% similarity. Sulfoxaflor did not affect body weight gain, feed intake,or the feed conversion ratio. Therefore, we concluded that pesticide residue quantification invivo to establish MRL could be performed using small laboratory animals instead of livestockanimals. This would contribute to obtaining in vivo pesticide residue information and reducinglarge-scale livestock animal experiments.

Aflatoxin B1-induced oxidative stress in canine small intestinal cells

조현우,서강민,이민영,이상엽,소경민,김기현,천주란 사단법인 한국동물생명공학회 2024 Journal of Animal Reproduction and Biotechnology Vol.39 No.2

Background: Aflatoxin B1 (AFB1) is a toxic metabolite generated by Aspergillus species and is commonly detected during the processing and storage of food; it is considered a group I carcinogen. The hepatotoxic effects, diseases, and mechanisms induced by AFB1 owing to chronic or acute exposure are well documented; however, there is a lack of research on its effects on the intestine, which is a crucial organ in the digestive process. Dogs are often susceptible to chronic AFB1 exposure owing to lack of variation in their diet, unlike humans, thereby rendering them prone to its effects. Therefore, we investigated the effects of AFB1 on canine small intestinal epithelial primary cells (CSIc). Methods: We treated CSIc with various concentrations of AFB1 (0, 1.25, 2.5, 5, 10, 20, 40, and 80 μM) for 24 h and analyzed cell viability and transepithelial-transendothelial electrical resistance (TEER) value. Additionally, we analyzed the mRNA expression of tight junction-related genes (OCLN, CLDN3, TJP1, and MUC2), antioxidant-related genes (CAT and GPX1), and apoptosis-related genes (BCL2, Bax, and TP53). Results: We found a significant decrease in CSIc viability and TEER values after treatment with AFB1 at concentrations of 20 μM or higher. Quantitative polymerase chain reaction analysis indiCATed a downregulation of OCLN, CLDN3, and TJP1 in CSIc treated with 20 μM or higher concentrations of AFB1. Additionally, AFB1 treatment downregulated CAT, GPX1, and BCL2. Conclusions: Acute exposure of CSIc to AFB1 induces toxicity, and exposure to AFB1 above a certain threshold compromises the barrier integrity of CSIc.