• 대한산업공학회지
• /
• 제33권2호
• /
• pp.265-272
• /
• 2007

The purpose of Vehicle Routing Problem (VRP) is to design the least costly (distance, time) routes for a fleet of identically capacitated vehicles to serve geographically scattered customers. There may be some restrictions such as the maximal capacity for each vehicle, maximal distance for each vehicle, time window to visit the specific customers, and so forth. This paper is concerned with VRP to minimize the sum of elapsed time from departure, where the elapsed time is defined as the time taken in a moving vehicle from the depot to each customer. It is important to control the time taken from departure in the delivery of perishable products or foods, whose freshness may deteriorate during the delivery time. An integer linear programming formulation is suggested and a heuristic for practical use is constructed. The heuristic is based on the set partitioning problem whose performances are compared with those of ILOG dispatcher. It is shown that the suggested heuristic gave good solutions within a short computation time by computational experiments.

• 한국임상보건과학회지
• /
• 제5권1호
• /
• pp.816-824
• /
• 2017

Purpose. This study was classified into normal and demented elderly through K-MMSE. The purpose of this study was to analyze gait characteristics of normal elderly and demented peoples using GAITRite walking system. Methods. The subjects of this study were selected as elderly people receiving home visit physical therapy. An independent t-test was conducted to verify the statistical significance of the time-space variables of the elderly with dementia. Results. Step time(p=0.041), cycle time(p=0.037), distance(p=0.024), and cadence(p=0.048) were significantly shorter in the normal elderly than in the demented elderly on flat place. The mean age was significantly longer in normal elderly than in elderly persons with dementia. Step time(p=0.022), cycle time(p=0.023), distance(p=0.019), and cadence(p=0.015) were significantly shorter in the mat walking. The mean age was significantly longer in normal elderly than in elderly patients with dementia. Stretch time, cycle time, distance, and hair support time were significantly shorter in the mat walking. The mean age of the elderly was significantly longer than that of the elderly with dementia. The spinal support time, which is a spatial variable, was significantly shorter in the normal elderly than in the demented elderly. Conclusions. It compares the various gait characteristics of the normal and demented elderly people, thereby increasing the walking ability of the elderly person more effectively. This study should be utilized as basic data for preventing fall-down.

• 보건행정학회지
• /
• 제26권3호
• /
• pp.233-241
• /
• 2016

Background: This study purposed to analyze and understand how spatial accessibility of patients influenced the number of outpatient visits for the internal medicine of a hospital. Methods: A hospital with 100 beds in Seoul, South Korea provided data from 2013 January 1 to 2013 June 30. Euclidean distance and road ares were used to represent the spatial accessibility. Patient level data and dong level data were collected and used in spatial analysis. Dong level data was converted into grid level ($500{\times}500m$) for the multivariate analysis. Hot-spot analysis and generalized linear model were applied to the data collected. Results: Hot-spots of outpatient visits were found around the study hospital, and cold-spots were not found. Number of outpatient visits was varied by the distance between patient resident and hospitals, and about 80% of total outpatient visits was occurred in within the 5 km from study hospital, and 50% was occurred in within 1.6 km. Spatial accessibility had significant influences on the outpatient visits. Conclusion: Findings provide evidences that spatial accessibility had influences on the patients' behaviors in utilizing the outpatient care of internal medicine in a hospital. Results can provide useful information to health policy makers as well as hospital managers for their decision making.

• 한국임상보건과학회지
• /
• 제3권3호
• /
• pp.399-408
• /
• 2015

Objective. There were two objectives of the study, first was to identify the barriers as perceived by the patients and providers to access the low vision services and second was to identify the challenges faced by the main providers. Study design. Structured questionnaire based interviews of patients and providers Methodology. To find out the barriers to access of low vision services, the interviews based on structured questionnaire were conducted for two patient groups. The first group consisted of 97 visually impaired individuals attending the department of low vision services at Al-Shifa Trust Eye Hospital Rawalpindi while the second group included 56 visually impaired individuals attending the four rehabilitation centers/schools for the blind in Rawalpindi/Islamabad. To identify the barriers as perceived by the main providers of low vision services and challenges faced by them the interviews based on structured questionnaire were conducted for 19 low vision service providers. Results. From patients point of view, major barrier to low vision services identified was inability to visit hospital /rehabilitation center alone - 29.8% in hospital group and 33.9% in rehabilitation centers group, while the lack of social support, lack of family support, cost of travelling, long distance, afford ability, hesitation in using devices and lack of satisfaction were other important barriers identified. From providers' point of view, major barrier to uptake of services was the need for repeated follow-ups. Optometrists were the main provider of low vision services contributing to 47.4% of the providers. The major challenge faced by the providers was motivation of patients to use low vision devices. Conclusion. The major barrier to low vision services according to the patients is inability to visit the hospital alone, while according to providers, it is the need for repeated follow up which proves major barrier towards uptake of services. The motivation is the major challenge faced by providers, majority of which are optometrists.

• 농촌계획
• /
• 제14권2호
• /
• pp.33-42
• /
• 2008

Recently, rural leisure by urban dwellers has been recognized as a catalyst for regional development or restoration. The federal government implemented several regional planning policies attempting to address this phenomenon in the late nineties. However, most of these policies focused on supply-centered planning, which caused a diverse set of problems relating to the sustainability and economic validity of the planning. Instead, this study focuses on the re-visitation one of the demand variables, with the intention of analyzing the character of rural leisure demand and its re-visitation choice attributes. For these reasons, this study investigates the character of current rural leisure demand, and develops functional equations about urban people who visit rural areas, using logit model. The results of this study can be summarized as follow: Urban people are visiting rural areas from nearby cities or metropolitan areas that are within 3 hours driving distance, and over 80% of rural visitors are one-day visitors. Therefore, most of their visitation activities should be understood as rural leisure, including rural tourism. In addition, the likelihood of the rural tourist to make a return visit is influenced by their transportation means, product purchasing, staying period and travel time. The results of such rural leisure demand can provide information for regional planning strategies, such as selection of target market, type of market segments, improvement of recognition level, activity program price, facility and space planning, produce sale and connection with tour site.

• 한국정보시스템학회지:정보시스템연구
• /
• 제31권3호
• /
• pp.47-65
• /
• 2022

Purpose With the recent development of Big Data and Artificial Intelligence technology, self-driving technology has developed into three stages (partial self-driving) or four stages (conditional self-driving), it is expected to bring a new paradigm to transportation in the city. Although many researchers are researching related technologies, there is no research on self-driving for disabled persons. In this study, the basic research was conducted based on the assumption that the shared self-driving car used by the disabled person is similar to the special transportation currently driving. Design In this study, data analysis and machine learning techniques were utilized to analyze the mobility patterns of disabled persons by type and to search for leading factors affecting the traffic volume of special transportation. Findings The study found that external physical disorders and developmental disorders often visit general welfare centers, internal organ disorders often visit general hospitals, and the elderly and mental disorders have various destinations. In addition, machine learning analysis showed that the main transportation routes for the disabled person use arterial roads and auxiliary arterial roads and that the ratio of building usage-related variables affecting the use of special transportation for a disabled person is high. In addition, the distance to the subway and bus stops was also mentioned as a meaningful variable. Based on these analysis results, it is expected that the necessary infrastructure for shared self-driving cars for disability person traffic will be used as meaningful research data in the future.

• 정보과학회 컴퓨팅의 실제 논문지
• /
• 제20권12호
• /
• pp.652-657
• /
• 2014

출발지와 도착지, 사용자가 방문해야 하는 POI(Point of Interest)유형들, 이 유형들 중 전체 혹은 부분에 대한 방문순서들이 주어질 때, 출발지에서 여러 방문순서를 만족시키는 순서대로 각 POI 유형별로 적어도 하나의 POI를 방문한 후 목적지에 도착하는 경로를 순차적 경로라 한다. 본 논문에선 이 경로 중 근사 최단 경로(Approximate Shortest Path)를 찾는다. 기존의 두 가지 기법은 방문한 POI(또는 출발지)와 방문해야 할 유형의 POI들과의 근접성 만을 보거나 후보군 선정 시 방문순서 및 네트워크를 고려하지 않고 출발지와 목적지를 이은 직선과 가까운 POI들로 경로를 찾는 문제를 갖고 있었다. 본 논문에서는 네트워크 탐색을 이용하여 출발지와 목적지 간 네트워크 경로에 근접한 POI를 후보군으로 선정하여 경로를 탐색하고, 이 경로 중 방문한 POI유형이 많은 경로에 적응적 우선순위를 주어 향상된 근사 최단 경로를 구하는 기법을 제안한다.

• 한국병원경영학회지
• /
• 제23권1호
• /
• pp.78-86
• /
• 2018

Purposes: This study identifies local Chinese consumers' standard for selecting medical care provider and their standard for choosing medical staff, as well as their expectations and concerns regarding Korean medical care providers. Methodology: A survey was conducted in China, to identify Chinese medical care consumers' standards for selecting a medical provider and the factors that influence their use of general hospitals. A total of 1,500 people across three cities, between the ages 18 and 60 participated in the survey. Moreover, a multiple logistic regression analysis was used to analyze the factors that affect Chinese medical care consumers' use of general hospitals. Findings: A total of 75.5 percent respondents chose general hospitals as their most frequently-used medical provider. Those who have health insurance, visit general hospitals as outpatients or are hospitalized more frequently than those who do not have a health insurance. Furthermore, those who have private insurance visit general hospitals as outpatients or are hospitalized more frequently than those who are not signed up for private insurance. Major standards for selecting a hospital included: the doctor's skills, word-of-mouth regarding the hospital, and distance to the hospital from the respondents' home. Standards for choosing medical personnel included word-of-mouth regarding the medical team, recommendations from family members or acquaintances, and medical team's notoriety. Friends and neighbors, family members, television and other media outlets were the channels for acquiring information on a hospital. It was found that Chinese people mostly visit the cardiovascular department of Korean hospitals for treatment. For using Korean hospitals in China, the majority of respondents answered that they were concerned about the cost. Practical Implications: Backed by highly skilled medical experts and cutting-edge technology, Korean medical care providers are attempting to enter China's medical care market. To succeed in China's medical care market, it is vital to conduct a clear and precise analysis.

• 한국안광학회지
• /
• 제14권3호
• /
• pp.65-73
• /
• 2009

목적: 노안보정용 안경 착용이 원용굴절력 및 근용가입도 변화에 미치는 영향을 조사하기 위하여 본 연구를 시행하였다. 방법: 42~75세 사이의 안과질환이 없고 백내장 수술 또는 망막질환의 경험이 없으며 교정시력이 20/20이면서 노안보정용 안경 착용 경험이 없는 대상자를 대조군, 돋보기 착용군 및 누진다초점안경 착용군으로 세분한 후 방문 시기에 따라 원용굴절력과 근용가입도를 측정하여 비교분석하였으며 추적 관찰은 최대 73개월 동안 진행하였다. 결과: 원용굴절력은 연령에 따라 원시안으로 변하는 경향이 있었으며(r=0.486, p<0.001) 연구기간 중 대상자의 50.0%에서 플러스 굴절력이 증가하였다. 돋보기 착용군의 년 간 플러스굴절력 증가량은 대조군 및 누진다초점안경 착용군과 유의한 차이를 보였으나(p<0.05), 누진다초점안경 착용군은 대조군과 차이가 없었다. 돋보기 착용군의 연간 근용가입도 증가량도 대조군 및 누진다초점안경 착용군보다 더 많았다(p<0.05). 결론: 중노년층에서는 연령관련 원시화현상이 나타날 수 있기 때문에 정기적인 굴절검사가 반드시 필요하며, 돋보기의 착용은 연령관련원시화 및 근용가입도의 증가를 유발시킬 수 있으나, 누진다초점안경의 처방은 원용굴절력과 근용가입도의 증가를 감소시킬 수 있을 것으로 사료된다.

• 한국환경과학회지
• /
• 제19권4호
• /
• pp.427-436
• /
• 2010

In this study this author made research and analysis on physical status and characteristics of community parks in Ik-san provinces and also depending on its potential resources such parks were classified into constructed parks and unconstructed parks and status of use of such parks and level of satisfaction were studied. Through this paper this author strived to provide basic data required for forming green track of land for the parks. Required time for visiting community parks either constructed or unconstructed type was within 40 minutes or less. However constructed parks appeared to be more convenient for access in comparison with natural unconstructed parks. Mostly they were used by residents in neighboring community and also residents in the area around it were found as using it frequently. At the time of using community parks either constructed or unconstructed types means of access were mostly by walking or by riding bicycles. Thus considering large number of users of such parks are from neighboring community it appeared that parks with its simplicity and convenience in terms of distance and with rich nature were preferred by users rather than large scale parks at distance. In terms of time frame of use and motivation of visit constructed parks were used mainly for exercise and relaxation in the morning at parks and its facilities whereas un constructed parks were mostly used in the afternoon for for walking and chatting and rest under with time to spare at shadows of its trees. Time spent at parks were composed mostly of rest and walking more frequently than exercise and leisure activity thus it was different from motivation for visiting parks. As for evaluation of use of parks natural elements, unique environment, trees and lawns featured highly in unconstructed parks in comparison with constructed parks. Thus it seemed visitors are more conscious of forest and landscape in a form of unchanged nature. Thus for community parks first consideration should be heightening accessibility in view of primary concern for convenience by users rather than facilities or environmental conditions.