• 제목/요약/키워드: Cause-Effect Model

검색결과 917건 처리시간 0.028초

지구온난화에 따른 국내 기후변화와 젖소 착유우의 생산효율에 미치는 영향 평가 : 모델 시뮬레이션을 이용한 접근 (Climate Change by Global Warming and Its Effects on Production Efficiency of Lactating Dairy Cows in Korea : a Simulation Modeling Approach)

  • 이정진;이준성;김종남;서자겸;조남철;박성민;기광석;서성원
    • 한국유기농업학회지
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    • 제21권4호
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    • pp.711-723
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    • 2013
  • 지난 25년간 지구온난화로 인한 국내 기후변화 양상은 지역 간에 차이가 있어, 고온지역은 평균온도의 증가를 보이지는 않았으나, 최저기온의 지속적인 상승과 그에 따른 열대야 발생을 확인할 수 있었다. 또한 그로 인한 젖소의 고온스트레스 발생, 섭취량의 감소 및 생산성 저하가 예상된다. 저온지역의 경우에는 여름철 평균온도 및 최저온도의 상승으로 인해 연평균기온이 유의적으로 상승한 반면, 겨울철에는 오히려 최저기온의 지속적인 하강이 관찰됨에 따라 동물의 저온스트레스가 가중될 것으로 예상된다. 착유우가 저온스트레스 상태에 있을 때는 에너지요구량과 건물섭취량이 증가하여 생산 효율이 떨어지며, 사료효율의 감소로 경제성은 감소되고 우유 생산비는 증가한다. 특히, 극심한 저온스트레스 또는 사료, 음수 및 우사바닥의 결빙은 섭취량 감소를 야기하며 이에 따른 생산성의 저하는 더욱 가중될 것으로 예상된다. 결론적으로 지구온난화로 인한 기후변화에 따른 지역별 영향은 다르며, 온도 스트레스에 의한 낙농우의 생산성 저하를 최소화하고, 동물의 복지와 건강을 증진시키기 위해서는 지역별 기후변화 특성에 맞춘 사양기술의 개발이 필요하다.

CFD 해석을 통한 후지 사과 CA 저장고 내의 적정 CO2 농도 조성 검토 (Evaluating Proper CO2 Concentrations in CA Storage of Fuji Apple using CFD Analysis)

  • 이상익;홍세운;최원;김락우;이인복
    • 한국농공학회논문집
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    • 제60권3호
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    • pp.71-81
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    • 2018
  • $CO_2$ concentration has a significant effect on quality of cold-stored apples. High indoor $CO_2$ concentrations above 10,000 ppm cause the browning of apples and result in economic loss for farmers. The purpose of this study is to evaluate $CO_2$ concentrations and their distribution in a controlled atmosphere (CA) storage and provide better structural designs to improve the $CO_2$ environment using computational fluid dynamics (CFD) simulations. The CFD model was developed for a real CA storage for apples and applied to investigate the effect of changing the inlet and outlet locations and the aspect ratio of the floor of the CA storage on the spatial distributions of $CO_2$ concentration and the browning of the apples. The lowest $CO_2$ concentrations in existing CA storage with a high aspect ratio of the floor were achieved from the combination of the inlet located at the top of the right side and the outlet located at the bottom of the left side. In modified CA storage with a low aspect ratio, the combination of the inlet and outlet located at top and bottom of left side respectively achieved the lowest $CO_2$ concentrations. The proposed case enhanced the storage performance by reducing total browned apples by 3.6% in storage duration of 210 days. This study is expected to reduce the browning damages of apples in CA storage, and thus greatly prevent economic losses.

활락효령단(活絡效靈丹)이 Angiogenesis 억제기전(抑制機轉)에 미치는 영향(影響) (Study on the Effect of Hwallakhyoreungdan(活絡效靈丹) on Angiogenic Inhibition Mechanism)

  • 나기환;최승훈;안규석
    • 대한한방종양학회지
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    • 제4권1호
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    • pp.17-36
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    • 1998
  • This experimental study was carried out to evaluate the effects of Hwallakhyoreungdan on angiogenic inhibition mechanism. In order to investigate the effects of Hwallakhyoreungdan on angiogenic inhibition mechanism, MTT assay, cell adhesive inhibition effect, DNA fragmantaion analysis, Nuclear condensation assay, FACScan analysis, Angiogenic lumen formation assay, Immunocytochemistry analysis, RT-PCR for mRNA expression, Western blot analysis and Confocal analysis for $Ca^{2+}$ change were performed. The results were summarized as follows: 1. The cell adhesive inhibition ability was strong from $5{\mu}g/ml$. 2. The $G_0/G_1$ arrest peak was existed on ECV304 cell-line. 3. The cells on Collagen plate were inhibition of proliferation and inducement of apoptosis by HR water extract. 4. Angiogenic lumen formation was inhibited by HR water extract. 5. LFA-1 and ELAM-1's expression were inhibited by HR water extract. They are commenly participation on inflammation and tumor regeneration. 6. The expression of MMP-9 and uPA were inhibited by HR water extract. 7. The expression of integrin ${\alpha}_v{\beta}_3$ was inhibited by HR water extract. 8. The expression of intracellular molecule were successively inhibited by HR water extract therefore the proliferation of ECV304 cell line was stopped and apoptosis was induced. 9. The change of $Ca^{2+}$ was decreased by HR water extract it cause confusion of signal transduction pathway therefore it was take part in apoptosis. According to the results, Hwallakhyoreungdan showed to be a key antaonist of integrin ${\alpha}_v{\beta}_3$, and to be induction of apoptosis by p53 through flow cytometry. This report also demonstrated that expressions of MMP-9 and uPA was blocked under the angiogenesis model. Thus, we suggests that Hwallakhyoreungdan blocks angiogenesis by inducing apoptosis of ECV304 and ECVPAR cell lines and another oriental herbal medicine that treats blood-stasis type also has angiogenic inhibition effects.

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정부의 전통시장 지원 정책 효과에 대한 실증연구 (The Policy Effects on Traditional Retail Markets Supported by the Korean Government)

  • 이규현;김용재
    • 유통과학연구
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    • 제13권11호
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    • pp.101-109
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    • 2015
  • Purpose - A traditional retail market is a place that offers economic opportunity to employees and employers alike it also is a place where the community can meet. The Korean government has invested three trillion won to improve physical and non-physical aspects in traditional retail markets since 2004. However, little research on this has been conducted. We explore this research gap that could lead to theory extension. We analyze consumption behavior with respect to traditional retail markets through an empirical analysis, thus overcoming limits in previous research. We empirically analyze policy effects of traditional retail market projects supported by the Korean government. Research design, data, and methodology - We propose a traditional retail market improvement plan via the relation between cause and effect resulting from the analysis. More specifically, logit analysis was carried out with 1,754 consumers in 16 cities nationwide. In order to analyze consumer consumption behaviors nationwide, the probability was analyzed using a logit model. This research analyzes the link between support and non-support by the Korean government using binary values. The dependent variable is whether Korean government support is implemented; the binomial logistic regression is used as the statistical estimation technique. The object variables are:1 (support) or 0 (nonsupport), and the prediction value is between 1 and 0. As a result of the factor analysis of questions related to attributes of service quality, four factors were extracted: convenience, product, facilities, and service. Results - The results indicate that convenience, product, and facilities have a significant influence on consumer satisfaction in accordance with the government's traditional retail market support. Additionally, the results reveal that convenience, product, facilities, and service all have a significant influence on consumer satisfaction in a traditional retail market's service quality and consumer satisfaction. Finally, the analysis indicates that the highly satisfied traditional retail market customer has a significant influence on revisit intention. Moreover, the results reveal that the highly satisfied traditional retail market customer has a significant influence on recommendation intention. Conclusions - This research focused on consumers nationwide to measure policy effects of traditional retail markets compared to previous research that focused on one traditional retail market or a specific area. We verified the relationship of service quality and customer satisfaction and consumer behavior based on service quality theory. The results indicate that consumer satisfaction of traditional retail markets supported by service quality factors has a significant impact. In a concrete form, the results indicate that these effects are from facility modernization projects and marketing support projects of the Korean government. The results also imply that these facility and management support effects from the Korean government have been consistent. We realize that the Korean government has to selectively support traditional retail markets in major cities and small and medium-sized cities. To that end, the Korean government needs to select a concentration strategy for the revitalization of traditional retail markets.

The Effect of Pulsatile Versus Nonpulsatile Blood Flow on Viscoelasticity and Red Blood Cell Aggregation in Extracorporeal Circulation

  • Ahn, Chi Bum;Kang, Yang Jun;Kim, Myoung Gon;Yang, Sung;Lim, Choon Hak;Son, Ho Sung;Kim, Ji Sung;Lee, So Young;Son, Kuk Hui;Sun, Kyung
    • Journal of Chest Surgery
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    • 제49권3호
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    • pp.145-150
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    • 2016
  • Background: Extracorporeal circulation (ECC) can induce alterations in blood viscoelasticity and cause red blood cell (RBC) aggregation. In this study, the authors evaluated the effects of pump flow pulsatility on blood viscoelasticity and RBC aggregation. Methods: Mongrel dogs were randomly assigned to two groups: a nonpulsatile pump group (n=6) or a pulsatile pump group (n=6). After ECC was started at a pump flow rate of 80 mL/kg/min, cardiac fibrillation was induced. Blood sampling was performed before and at 1, 2, and 3 hours after ECC commencement. To eliminate bias induced by hematocrit and plasma, all blood samples were adjusted to a hematocrit of 45% using baseline plasma. Blood viscoelasticity, plasma viscosity, hematocrit, arterial blood gas analysis, central venous $O_2$ saturation, and lactate were measured. Results: The blood viscosity and aggregation index decreased abruptly 1 hour after ECC and then remained low during ECC in both groups, but blood elasticity did not change during ECC. Blood viscosity, blood elasticity, plasma viscosity, and the aggregation index were not significantly different in the groups at any time. Hematocrit decreased abruptly 1 hour after ECC in both groups due to dilution by the priming solution used. Conclusion: After ECC, blood viscoelasticity and RBC aggregation were not different in the pulsatile and nonpulsatile groups in the adult dog model. Furthermore, pulsatile flow did not have a more harmful effect on blood viscoelasticity or RBC aggregation than nonpulsatile flow.

Erythropoietin의 투여가 신생백서 저산소허혈뇌손상에 미치는 영향 (The effect of erythropoietin in neonatal rat model of hypoxic-ischemic brain injury)

  • 김행미;최병호;권순학;손윤경
    • Clinical and Experimental Pediatrics
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    • 제52권1호
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    • pp.105-110
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    • 2009
  • 목적 : 신생 백서의 저산소 허혈 뇌손상에 있어서의 erythropietin (Epo) 투여의 손상 예방 효과와 보호 기전에 철 대사가 관여하는지를 조사하고자 하였다. 방 법 : 신생 백서를 암수 구별 없이 생후 7일째에 편측 온목동맥 결찰 후 산소 농도 8%인 환경에 2시간 노출시켜 저산소 허혈을 유도하였으며 저산소 노출 직후 Epo 5,000 u/kg를 복강내 투여하였다. 이들은 저산소 허혈 유도 전 투여한 생리식염수, 철, deferoxamine 등에 따라 Epo군, Iron+Epo군, Def+Epo군, Iron+ Def+Epo군, 대조군으로 나누어 저산소 허혈 유도 후 7일에 뇌손상 정도를 비교하였다. 결 과 : Epo 투여시 뇌손상의 빈도와 정도는 대조군에 비해 감소하였다. 뇌손상의 빈도와 손상 점수로 뇌손상 정도를 비교한 결과 철 투여는 Epo의 뇌손상 예방 효과를 감소시키지 않았다. Deferoxamine 투여는 Epo 단독 투여군에 비해 뇌손상의 빈도와 정도가 경감하였으나 통계적 유의성은 없었다. 결 론 : Epo는 저산소 허혈 뇌손상에 있어 뇌손상 보호 효과를 보인다. 철 투여는 뇌손상을 악화시키지 않았으나 deferoxamine 동시 투여는 Epo 단독 투여에 비해 뇌손상의 빈도와 손상 점수가 감소하여 뇌손상 보호 효과에 철 대사가 관여할 가능성을 제시하였다.

간질성 방광염 환자 25예에 대한 임상적 고찰 (Clinical Study of 25 Interstitial Cystitis Patients)

  • 손기정;오현조;이중곤;남승규;김철중;조충식
    • 대한한방내과학회지
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    • 제33권2호
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    • pp.222-230
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    • 2012
  • Background : Interstitial cystitis is a disorder of the bladder characterized by urgency and frequency of urination, and pelvic pain. The cause of interstitial cystitis is not clear. Modern medical treatments include behavioral therapy, medication, intravesical infusion therapy, and surgical treatment, but the goal of treatment is based on symptom relief rather than a cure. According to a recent report, in an animal model, oriental medicine treatment, Yukmijihwang-tang improved the symptoms of interstitial cystitis. However, clinical studies and experimental research are lacking. Objectives : In this study, We investigated Chuknyojetong-tang, acupuncture, moxibustion and bee venom effect on interstitial cystitis. Methods : We targeted 25 patients diagnosed with interstitial cystitis at the university hospital and treated them for more than one month. We used acupuncture, Chuknyojetong-tang, and bee venom. The effects were evaluated using ICSI and ICPI at the begin of treatment and at the end of treatment. Results : All of the 25 patients were female, average age was $53.3{\pm}13.5$ years, and the average month of disease-duration was $69.0{\pm}59.8$. The duration of treatment was $8.0{\pm}5.4$ months, and 60% of patients were improved. After treatment, we used correlation coefficient method, multiple regression analysis. ICSI difference increased as treatment period increased. ICPI difference increased as age decreased. Total difference also increased as treatment period increased. These results imply that treatment effect was improved. Conclusions : These findings suggest that oriental medicine therapy using Chuknyojetong-tang, acupuncture, moxibustion, and bee venom would be very effective on interstitial cystitis.

말기암환자 가족에 대한 호스피스 케어의 정보적 지지 제공 효과

  • 김현숙
    • 호스피스학술지
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    • 제2권1호
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    • pp.21-40
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    • 2002
  • Cancer is the second leading cause of the death in Korea. Family caregivers of dying patients manifest many psychological and physical symptoms of stress, and they often seek for informational support from health care providers. Unfortunately, however, few systematic studies identify the actual effect of such support on family caregivers. This study, thus, intends to evaluate the effect of informational support for hospice care. One group pretest-posttest design was used, employing the stress-coping model by Cohen and Wills as a conceptual framework. This research was conducted from July 1 to November 15, 1998, initially with 32 subjects sampled from hemato-oncology department of two general hospitals in Seoul, but reduced to 18 at the end due to the untimely death of patients or caregiver's refusal during the course of study. Informational supports were programmed to provide the family caregivers with 8 times of education and counseling as well as 24-hour hot-line for 4 weeks. A booklet that explains the various problems of hospice care was also prepared and distributed to all subjects. Data were collected by using self-report questionnaires and reviewing medical records. The tools used in this study were based on the Weinert's PRQ-II(scale of perceived social support), Spielberger's state anxiety inventory, and CES-D. Also included in the data collection were the general characteristics of family caregivers and patients, and the pain intensity and the performance status of patients. The data were analyzed with descriptive statistics, Wilcoxon sign rank test and paired t-test using SPSSWIN program. The results of the study were as follows: 1.The perceived social support of family caregivers was not significantly increased with informational support for hospice care(t=1.64, one tailed p=.060). 2.The anxiety of family caregivers was significantly reduced following informational support for hospice care(t=3.48, one tailed p=.002). 3.The depression of family caregivers was significantly reduced following informational support for hospice care(t=-2.18, one tailed=.022). 4.The pain intensity of patients with terminal cancer was significantly reduced following informational support for hospice care(t=-2.41, two tailed p=.027). The results suggest that the informational support provided to family caregivers of patients with terminal cancer reduced not only their anxiety and depression but also the pain intensity of patients. Further study is necessary to consolidate the conceptual framework of this study with expanded number of subjects. Nevertheless, it was certain that the informational support program for hospice care was very helpful to both caregivers and patients. Thus, the informational support program is strongly recommended for the hospitals which have no hospice unit yet.

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강섬유 콘크리트 혼입율에 따른 내부앵커형 콘크리트 충전기둥 내화성능에 관한 해석적 연구 (Analysis Study on Fire Performance with Internal Anchored Concrete Filled Steel Tube Columns According to Percent of Steel-Fibers)

  • 김선희;염경수;김용환;최성모
    • 한국강구조학회 논문집
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    • 제28권1호
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    • pp.23-34
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    • 2016
  • 콘크리트 충전강관 기둥은 강관의 구속효과에 의해 콘크리트의 압축내력 상승과, 콘크리트에 의한 강관의 국부좌굴 보강효과에 의해 부재내력이 상승하고 뛰어난 변형성능을 발휘한다. 하지만, 기둥단면이 커질 경우 합성효과를 발휘하기 위하여 스터드 볼트나 후 시공 앵커 볼트를 사용해야 하는 시공상의 문제점이 발생된다. 이를 극복함과 동시에 합성효과를 증대시키기 위한 방안으로 내부에 리브가 설치된 용접조립 기둥이 소개되었다. 내부 리브는 콘크리트와 맞물려 있어 리브의 변형은 콘크리트의 균열을 촉진시키는 역할을 동반하게 된다. 이러한 잠재적인 문제에 대한 해결책은 강관 리브의 변형에 저항할 수 있도록 콘크리트 인성을 증가시킬 수 있는 방안이 필요하다. 언급된 두 가지의 문제점이 효과적으로 해결될 경우 용접조립 각형강관 기둥은 내화성능 확보가 가능하다고 판단된다. 본 연구에서는 해결방안으로 내부 콘크리트를 강섬유와 혼입하여 기둥 자체의 연성과 인성을 증대시키는 것에 중점을 맞추고 있다. 내화성능 평가를 위한 시험체는 총 8개 로 하중비에 따른 재하가열 실험을 실시하고 화재 전후 거동과 열 변형 능력을 주요변수별로 분석하였다. 실험결과와 선행연구 비교를 통해 열 전달과 열응력 해석 모델의 신뢰성을 확보하였으며, 강섬유 혼입율에 따른 변수해석을 수행하였다.

비균질 팬텀에서 소조사면에 대한 필름측정, 회선/중첩 모델과 몬테 카를로 모사의 비교 연구 (Comparison of Film Measurements, Convolution$^{}$erposition Model and Monte Carlo Simulations for Small fields in Heterogeneous Phantoms)

  • 김상노;제이슨손;서태석
    • 대한의용생체공학회:의공학회지
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    • 제25권2호
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    • pp.89-95
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    • 2004
  • 세기조절방사선치료(IMRT)에서는 일반적인 방사선 치료에서 사용되는 조사면에 비해 비교적 작은 크기의 빔조각(beamlet)을 사용하여 방사선의 세기를 조절하는 새로운 치료법으로 이에 대한 비균질 효과는 많은 연구가 필요하다. 우리는 기하학적으로 일정한 비균질 팬텀들에서 몬테카를로 시뮬레이션에 의한 선량값을 라디오크로믹 필름에 의한 선량값과 회선/중첩 방법에 의한 선량 계산 값과 서로 비교하였다. 몬테 카를로 모사를 위하여 EGS4 코드 기반의 BEAM 코드를 사용하였으며 이를 이용하여 Varian 2300C/D 선형가속기의 두부를 호사하였다. 측정과 모사에 사용된 조사면은 1${\times}$1$\textrm{cm}^2$, 2${\times}$2$\textrm{cm}^2$, 그리고 5${\times}$5$\textrm{cm}^2$이었다. 또한 팬텀의 물질은 솔리드 워터, 폐 등가 물질, 뼈 등가 물질을 사용하여 세 경우의 비극질 팬텀들을 설정하여 방사선을 조사하였다. 회선/중첩 방법과 몬테 카를로 방법에 의한 선량 계산치는 광자 측면선량의 경우 $\pm$1 mm, 깊이선량의 경우 $\pm$2% 이내로 선량측정치와 잘 일치함을 볼 수 있었다. 결론적으로 회선/중첩 방법과 몬테 카를로 방법이 소조사면에서도 필름 측정 데이터와 잘 일치함을 확인할 수 있었다.