• 제목/요약/키워드: scale-model

검색결과 8,442건 처리시간 0.039초

Research Methodology for the Economic Impact Assessment of Natural Disasters and Its Applicability for the Baekdu Mountain Volcanic Disaster (자연재해의 경제적 영향평가 연구방법론과 백두산화산재해에의 적용 가능성)

  • Jiang, Zhuhua;Yu, Soon-Young;Yoon, Seong-Min
    • Economic and Environmental Geology
    • /
    • 제47권2호
    • /
    • pp.133-146
    • /
    • 2014
  • There are many studies for the economic impact assessment of natural disasters, but there are few for volcanic disasters. Domestic academic research is not under active discussion because of the lack of national and social interest for volcanic eruption. This study investigated the research methodology for the economic impact assessment of natural disasters and discussed whether these can be applied to the economic impact analysis for the Baekdu Mountain volcanic disaster. The main findings are as follows: Firstly, Asia-Pacific region is the most affected by natural disasters and has the largest scale of damage. Asian and American Continent have the most economic damage. Secondly, Considering the types of damage caused by natural disasters and its complex structure, several methodologies that could be possible to estimate economic consequential damages have been compared. When applying each methodology to the Baekdu Mountain volcanic disaster, the scale of damage is likely to be over-estimated or under-estimated because of model-specific features. Thus, estimated values should be compared to each other after calculating the damage results. Thirdly, Japanese academic research on the volcanic disaster will be used as the starting point of the economic impact assessment studies for Baekdu Mountain. Using computer SW such as Hazus which is used in United States and RiskScape from New Zealand is also a good method to predict economic impact of the Baekdu Mountain volcanic disaster.

Robust Design Method for Complex Stochastic Inventory Model

  • Hwang, In-Keuk;Park, Dong-Jin
    • Proceedings of the Korean Operations and Management Science Society Conference
    • /
    • 한국경영과학회/대한산업공학회 1999년도 춘계공동학술대회:정보화시대의 지식경영
    • /
    • pp.426-426
    • /
    • 1999
  • ;There are many sources of uncertainty in a typical production and inventory system. There is uncertainty as to how many items customers will demand during the next day, week, month, or year. There is uncertainty about delivery times of the product. Uncertainty exacts a toll from management in a variety of ways. A spurt in a demand or a delay in production may lead to stockouts, with the potential for lost revenue and customer dissatisfaction. Firms typically hold inventory to provide protection against uncertainty. A cushion of inventory on hand allows management to face unexpected demands or delays in delivery with a reduced chance of incurring a stockout. The proposed strategies are used for the design of a probabilistic inventory system. In the traditional approach to the design of an inventory system, the goal is to find the best setting of various inventory control policy parameters such as the re-order level, review period, order quantity, etc. which would minimize the total inventory cost. The goals of the analysis need to be defined, so that robustness becomes an important design criterion. Moreover, one has to conceptualize and identify appropriate noise variables. There are two main goals for the inventory policy design. One is to minimize the average inventory cost and the stockouts. The other is to the variability for the average inventory cost and the stockouts The total average inventory cost is the sum of three components: the ordering cost, the holding cost, and the shortage costs. The shortage costs include the cost of the lost sales, cost of loss of goodwill, cost of customer dissatisfaction, etc. The noise factors for this design problem are identified to be: the mean demand rate and the mean lead time. Both the demand and the lead time are assumed to be normal random variables. Thus robustness for this inventory system is interpreted as insensitivity of the average inventory cost and the stockout to uncontrollable fluctuations in the mean demand rate and mean lead time. To make this inventory system for robustness, the concept of utility theory will be used. Utility theory is an analytical method for making a decision concerning an action to take, given a set of multiple criteria upon which the decision is to be based. Utility theory is appropriate for design having different scale such as demand rate and lead time since utility theory represents different scale across decision making attributes with zero to one ranks, higher preference modeled with a higher rank. Using utility theory, three design strategies, such as distance strategy, response strategy, and priority-based strategy. for the robust inventory system will be developed.loped.

  • PDF

The Influence of Health Behaviors and Sleep related Factors on Cognitive Function in the Elderly Hypertensive Patients (노인 고혈압 환자의 건강행태 및 수면 관련 요인이 인지기능에 미치는 영향)

  • Kim, Ahrin;Jeon, Hae Ok
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • 제16권10호
    • /
    • pp.7078-7088
    • /
    • 2015
  • This study examined effects of health behaviors and sleep related factor on cognitive function in the elderly hypertensive patients. Data were collected through a face to face interview survey with structured questionnaire form 140 elderly with hypertension ($age{\geq}65years$) from February 5 to May 1, 2013. Research instruments included Pittsburgh Sleep Quality Index(PSQI), Epworth Sleepiness Scale(ESS) and Korean version the Mini-Mental State Examination(MMSE-K). Cognitive function was negatively related to degradation in quality of sleep(r=-.29, p<.001). Sleep duration were negatively related to body mass index(r=-.18, p=.032) and degradation in quality of sleep(r=-.59, p<.001). Sleep duration was positively related to daytime sleepiness(r=.22, p=.008). Hierarchical multiple regression showed that age, education levels and living arrangement were associated with cognitive function(F=8.56, p<.001, Adjusted $R^2=.14$). After controlling for demographic characteristics and health behaviors, degradation in quality of sleep(${\beta}=-.27$, p=.008) was identified as significant predictors of cognitive function. This final model explained 17.0% of the cognitive function in the elderly hypertensive patients(F=4.09, p<.001). Therefore, as a strategy improving cognitive function of the elderly with hypertension, therapeutic intervention should be developed to improve quality of sleep considering age, education levels and living arrangement.

Factors Influencing on the Subjective Happiness of Senior Nursing Students (고학년 간호대학생의 주관적 행복감에 영향을 미치는 요인)

  • Cho, In Young
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • 제21권3호
    • /
    • pp.118-128
    • /
    • 2020
  • This descriptive study investigated the factors influencing on subjective happiness of senior nursing students. The participants were 235 nursing students in grades 3 and 4 in K city from May 1, 2019 to May 28, 2019. The data was collected using self-report questionnaires that contained items on subjective happiness, professional intuition, human relationship, major satisfaction, family health, and social support scale. The data was analyzed using descriptive statistics, Pearson's correlation coefficients, and stepwise multiple regression analysis with the SPSS 22.0 program. The subjective happiness of the subjects averaged 4.75±1.16 on the 7-point scale, and the subjective happiness according to the general characteristics of the subjects showed a significant difference in health status (F=6.826, p<.001). The most influential factors on the subjects' subjective happiness were health status (β=.177 p=.005), academic satisfaction (β=.138, p=.027), and family health (β=.268, p<.001), and the explanatory power of the model was 16.7% (F=15.160, p<.001). The results of this study may provide a foundation to develop an efficient intervention program to improve the happiness of senior nursing students.

Sales Commission of Department Store and Policy Implications (백화점의 판매수수료 현황 및 정책대응 방안)

  • Lee, Jung-Hee;Hwang, Seong-Huyk;Kim, Sung-Min
    • Journal of Distribution Research
    • /
    • 제15권5호
    • /
    • pp.37-60
    • /
    • 2010
  • Department Stores have been in place as typical large-scale retailer in Korean retail market. After Asian financial crisis in 1997, the market share of major three department stores has been increased and they have had a dominant position in relationship with vendors or manufacturers. Thus, they are able to control sales commission. Sales commission is defined as things that department stores which contribute to products sales instead of manufacturers take some portion of price as their revenue. In other words, vendors or manufacturers pay some amount of money from their sales by contracted ratio to department stores. The problem is that vendors or manufacturers think that sales commission is high. However, department stores have a different opinion that sales commission is not high because they generate new value from gathering customers and doing marketing activity on behalf of vendors or manufacturers. Because department stores have operated with business model of renting sales space to vendors or manufacturers instead of buying goods directly from them, this situation has been taken place. The revenue of department stores depend on sales commission. Thus, they want to get a dominant power to control sales commission in relationship with vendors or manufacturers. So, they have tried to increase their size and brand power. The considered policies related in sales commission of department stores are as following: preventing monopoly or oligopoly of department store, being strength of monitoring for department stores' unfair trade, strict enforcement of law for large-scale retailer's unfair trade, and inducing win-win strategy doing voluntarily by department stores.

  • PDF

Effects of Urban Environments on Pedestrian Behaviors: a Case of the Seoul Central Area (보행에 대한 도시환경의 차이: 서울 도심을 중심으로)

  • Kwon, Daeyoung;Suh, Tongjoo;Kim, Soyoon;Kim, Brian Hong Sok
    • Journal of Korean Society of Transportation
    • /
    • 제32권6호
    • /
    • pp.638-650
    • /
    • 2014
  • The objective of this study is to identify the causes of pedestrian volume path to the destination by investigating the influential levels of regional and planning features in the central area of Seoul. Regional characteristics can be classified from the result of the analysis and through the spatial characteristics of pedestrian volume. For global scale analysis, Ordinary Least Squares (OLS) regression is used for the degree of influence of each characteristics to pedestrian volume. For the local scale, Geographically Weighted Regression (GWR) is used to identify regional influential factors with consideration for spatial differences. The results of OLS indicate that boroughs with transportation facilities, commercial business districts, universities, and planning features with education research facilities and planning facilities have a positive effect on pedestrian volume path to the destination. Correspondingly, transportation hubs and congested areas, commercial and business centers, and university towns and research facilities in the Seoul central area can be identified through the results of GWR. The results of this study can provide information with relevance to existing plans and policies about the importance of regional characteristics and spatial heterogeneity effects on pedestrian volume, as well as significance in the establishment of regional development plans.

Study on the Correlation between Patients Complaints of Dyspepsia and Stress -Through comparison between functional dyspepsia patients and nonsymptomatic chronic gastritis patients- (소화불량(消化不良)과 과심상(過心傷)의 상관성(相關性)에 대(對)한 고찰(考察) -스트레스, 기울(氣鬱), 비병증(脾病證)의 평가(評價)를 통(通)해-)

  • Kim, Jin-Sung;Yoon, Sang-Hyub;Ryu, Bong-Ha;Ryu, Ki-Won;Lee, Sang-Wook
    • The Journal of Internal Korean Medicine
    • /
    • 제25권4호
    • /
    • pp.306-317
    • /
    • 2004
  • Background & Object : Dyspepsia for which no organic causes are disclosed is referred to as functional dyspepsia. Functional dyspepsia is here studied in connection with a biopsychosocial model. From the aspect of individual response to external environment, in connection with stress response, functional dyspepsia is studied by both the psychology department and the internal medicine departments. The disease is taken as approachable from the aspect of internal injury due to seven emotions and stress as differentiated by Oriental medicine. Materials and Methods : Targeted at 223 patients underwent medical checks and endoscopy at Kangnam Korean Hospital, Kyunghee University. They agreed to join this clinical experiment. Stress response inventory, GARS (global assessment of recent stress scale), GSRS (gastrointestinal symptom rating scale), diagnostic scores for Ki-depression, and Spleen Disease Differentiation of Syndromes were all measured and evaluated. The test group was comprised of functional dyspepsia patients. The control group was comprised of nonsymptomatic chronic gastritis patients who were found to suffer from chronical gastritis in endoscopy and thus could be diagnosed with functional dyspepsia if symptoms would arise, but did not complain of subjective symptoms. Results showed these corelations: Functional dyspepsia patients were found to have more serious Ki-depression compared to nonsymptomatic chronic gastritis patients. The more serious Ki-depression the more serious the dyspepsia symptoms. The higher the stress response inventory the more serious the dyspepsia. Deficiency of spleen Eum, and Deficiency and Sinking of spleen Gi were found to coincide with serious Ki-depression.

  • PDF

Exploitation of the Dose/Time-Response Relationship for a New Measure of DNA Repari in the Single-Cell Gel Electrophoresis (Comet) Assay

  • Kim, Byung-Soo;Edler, Lutz;Park, Jin-Joo;Fournier, Dietrich Von;Haase, Wulf;Sautter-Bihl, Mare-Luise;Hagmuller, Egbert;Gotzes, Florian;Thielmann, Heinz Walter
    • Toxicological Research
    • /
    • 제20권2호
    • /
    • pp.89-100
    • /
    • 2004
  • The comet assay (also called the single-cell gel electrophoresis assay) has been widely used for detecting DNA damage and repair in individual cells. Since the conventional methods of evaluating comet assay data using frequency statistics are unsatisfactory we developed a new quantitative measure of DNA damage/repair that is based on all information residing in the dose/time-response curves of a comet experiment. Blood samples were taken from 25 breast cancer patients before undergoing radiotherapy. The comet assay was performed under alkaline conditions using isolated lymphocytes. Tail DNA, tail length, tail moment and tail inertia of the comet were measured for each patient at four doses of $\gamma$-rays (0, 2, 4 and 8 Gy) and at four time points after irradiation (0, 10, 20 and 30 min) using 100 cells each. The resulting three-dimensional dose-time response surface was modeled by multiple regression, and the second derivative, termed 2D, on dose and time was determined. A software module was programmed in SAS/AF to compute 2D values. We applied the new method successfully to data obtained from cancer patients to be assessed for their radiation sensitivity. We computed the 2D values for the four damage measures, i.e., tail moment, tail length, tail DNA and tail inertia, and examined the pairwise correlation coefficients of 2D both on the log scale and the unlogged scale. 2D values based on tail moment and tail DNA showed a high correlation and, therefore, these two damage measures can be used interchangeably as far as DNA repair is concerned. 2D values based on tail inertia have a correlation profile different from the other 2D values which may reflect different facets of DNA damage/repair. Using the dose-time response surface, other statistical models, e.g., the proportional hazards model, become applicable for data analysis. The 2D approach can be applied to all DNA repair measures, Le., tail moment, tail length, tail DNA and tail inertia, and appears to be superior to conventional evaluation methods as it integrates all data of the dose/time-response curves of a comet assay.

Effect of Rehabilitation Intervention for Lifestyle Improvement of Spinal Cord Injury: Systematic Review of Randomized Controlled Trials and Meta-Analysis (척수 손상 환자의 라이프 스타일 개선을 위한 재활 중재 효과: 무작위 대조군 연구의 체계적 고찰 및 메타분석)

  • Ha, Sung Kyu;Park, Hae Yean
    • Therapeutic Science for Rehabilitation
    • /
    • 제9권4호
    • /
    • pp.107-120
    • /
    • 2020
  • Objective : The purpose of this study was to investigate the effectiveness and basis of rehabilitation intervention in patients with spinal cord injury by systematic review and meta-analysis of randomized controlled studies. Methods : Two researchers independently searched and selected a study published in an academic journal using a search term in an international thesis database. A total of 21 studies met the selection criteria, and qualitative evaluation of the study was conducted using the PEDro Scale. Meta-analysis was performed using Comprehensive Meta-Analysis 3.0 program. Results : A total of 713 subjects were included. The results of the meta-analysis showed a score of 0.406 (95.0% confidence interval: 0.221 ~ 0.591) for intervention using physical activity and 0.505 (95.0% confidence interval: 0.449 ~ 1.528) for electronic stimulation therapy, which showed medium effect; educational intervention had a 0.248 (95.0% confidence interval: 0.033 ~ 0.464), and mixed intervention 0.280 (95.0% confidence interval: 0.122 ~ 0.438). It was shown that the effect of small (small). There was a significant heterogeneity in the statistical heterogeneity test, and thus the random effects model was selected and analyzed. Conclusion : The results showed that rehabilitation interventions were effective for patients with spinal cord injury. During the rehabilitation of spinal cord injury patients, clinicians are expected to contribute to the development of programs to improve their lifestyles.

Azimuthal Distribution of Daily Maximum Temperatures Observed at Sideslopes of a Grass-covered Inactive Parasitic Volcano ("Ohreum") in Jeju Island (제주도 초지피복 기생화산("오름")의 방위별 일 최고기온 분포)

  • Seo, Hee-Chul;Jeon, Seung-Jong;Yun, Jin-I.
    • Korean Journal of Agricultural and Forest Meteorology
    • /
    • 제10권1호
    • /
    • pp.25-31
    • /
    • 2008
  • Information on daily maximum air temperature is important in predicting the status of plants and insects, but the uneven and sparse distribution of weather stations prohibits timely access to the data in regions with complex topography. Since cumulative solar irradiance plays a critical role in determining daily maximum temperature on any sloping surfaces, derivation of a quantitative relationship between cumulative solar irradiance and the resultant daily maximum temperature is a prerequisite to development of such estimation models. Air temperatures at 8 sideslope locations with similar elevation and slope angle but aspect, circumventing a cone-shaped, grass-covered parasitic volcano (c.a., 570 m diameter for the bottom circle and 90m bottom-to-top height), were measured from June to December in 2007. Daily maximum temperatures from each location were compared with the average of 8 locations (assumed to be the temperature measured at a "horizontal reference" position). The temperature deviation at all locations increased with the day of year (or sun elevation) from summer solstice to winter solstice. Averaged over the entire period, the south facing location was warmer by $1^{\circ}C$ in daily maximum temperature than "horizontal reference" and the north facing location was cooler by $0.8^{\circ}C$ than the reference, resulting in the year round average south-north temperature difference of $1.8^{\circ}C$. In November, both south and north facing slopes showed the greatest deviation of $+2.0^{\circ}C$ and $-1.3^{\circ}C$, respectively in daily maximum temperature at monthly scale. On a daily scale, the greatest deviation was +3.8 and $2.7^{\circ}C$ at the south and north slope, respectively. The cumulative solar irradiance (on the slope for 4 hours from 11:00 to 15:00 TST) explained >60% of the variance in daily maximum temperature deviations among 8 locations, suggesting a feasibility of developing an estimation model for daily maximum temperature over complex topography at landscape scales.