• Title/Summary/Keyword: Priority estimation

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Estimation of Road-Network Performance and Resilience According to the Strength of a Disaster (재난 강도에 따른 도로 네트워크의 성능 및 회복력 산정 방안)

  • Jung, Hoyong;Choi, Seunghyun;Do, Myungsik
    • International Journal of Highway Engineering
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    • v.20 no.1
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    • pp.35-45
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    • 2018
  • PURPOSES : This study examines the performance changes of road networks according to the strength of a disaster, and proposes a method for estimating the quantitative resilience according to the road-network performance changes and damage scale. This study also selected high-influence road sections, according to disasters targeting the road network, and aimed to analyze their hazard resilience from the network aspect through a scenario analysis of the damage recovery after a disaster occurred. METHODS : The analysis was conducted targeting Sejong City in South Korea. The disaster situation was set up using the TransCAD and VISSIM traffic-simulation software. First, the study analyzed how road-network damage changed the user's travel pattern and travel time, and how it affected the complete network. Secondly, the functional aspects of the road networks were analyzed using quantitative resilience. Finally, based on the road-network performance change and resilience, priority-management road sections were selected. RESULTS : According to the analysis results, when a road section has relatively low connectivity and low traffic, its effect on the complete network is insignificant. Moreover, certain road sections with relatively high importance can suffer a performance loss from major damage, for e.g., sections where bridges, tunnels, or underground roads are located, roads where no bypasses exist or they exist far from the concerned road, including entrances and exits to suburban areas. Relatively important roads have the potential to significantly degrade the network performance when a disaster occurs. Because of the high risk of delays or isolation, they may lead to secondary damage. Thus, it is necessary to manage the roads to maintain their performance. CONCLUSIONS : As a baseline study to establish measures for traffic prevention, this study considered the performance of a road network, selected high-influence road sections within the road network, and analyzed the quantitative resilience of the road network according to scenarios. The road users' passage-pattern changes were analyzed through simulation analysis using the User Equilibrium model. Based on the analysis results, the resilience in each scenario was examined and compared. Sections where a road's performance loss had a significant influence on the network were targeted. The study results were judged to become basic research data for establishing response plans to restore the original functions and performance of the destroyed and damage road networks, and for selecting maintenance priorities.

Estimation of Seismic Performance and Earthquake Damage Ratio of Existing Reinforced Concrete Buildings in Japan (일본의 기존 철근콘트리트건물의 내진성능 및 지진피해율의 평가)

  • 이강석;이리형
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.13 no.1
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    • pp.63-74
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    • 2000
  • The main objective of this paper is to apply as the basic data for development of a methodology to discuss the future earthquake preparedness measures in Korea by investigating the concept and applicabilities of the Japanese Standard for Evaluation of Seismic Performance of Existing RC Buildings developed in Japan among the methodologies of all the countries of the world. This paper describes the seismic performance, Is-index, of existing RC buildings in Tokyo, Japan evaluated by the Japanese Standard, also the relationships between Is-index distribution of existing RC buildings in Tokyo and that of Shizuoka and Chiba Prefecture reported already in reference[4][5][6] are investigated. And from the comparison with Is-index to buildings damaged by earthquakes experienced in Japan, the damage ratio due to severe earthquake of 3 districts mentioned above is estimated based on the probabilistic point of view. The results of this study can be utilized to identify urgently required earthquake preparedness measures with highest priority in existing RC buildings, and the methodology to evaluate the seismic performance of existing RC buildings in Japan, statistics analysis method and the methodology to estimate earthquake damage ratio based on the probabilistic point of view shown in this study can be recommended to develop a methodology to discuss the future earthquake preparedness measures in Korea.

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Conceptual Design of Automatic Control Algorithm for VMSs (VMS 자동제어 알고리즘 설계)

  • 박은미
    • Journal of Korean Society of Transportation
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    • v.20 no.7
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    • pp.177-183
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    • 2002
  • Current state-of-the-art of VMS control is based upon simple knowledge-based inference engine with message set and each message's priority. And R&Ds of the VMS control are focused on the accurate detection and estimation of traffic condition of the subject roadways. However VMS display itself cannot achieve a desirable traffic allocation among alternative routes in the network In this context, VMS display strategy is the most crucial part in the VMS control. VMS itself has several limitations in its nature. It is generally known that VMS causes overreaction and concentration problems, which may be more serious in urban network than highway network because diversion should be more easily made in urban network. A feedback control algorithm is proposed in this paper to address the above-mentioned issues. It is generally true that feedback control approach requires low computational effort and is less sensitive to models inaccuracy and disturbance uncertainties. Major features of the proposed algorithm are as follows: Firstly, a regulator is designed to attain system optimal traffic allocation among alternative routes for each VMS in the network. Secondly, strategic messages should be prepared to realize the desirable traffic allocation, that is, output of the above regulator. VMS display strategy module is designed in this context. To evaluate Probable control benefit and to detect logical errors of the Proposed feedback algorithm, a offline simulation test is performed using real network in Daejon, Korea.

A Study on Low-Floor Bus Routes Selection - Focused on the Case of Jeollabuk-Do - (저상버스 노선선정 방안에 관한 연구 -전라북도 사례를 중심으로-)

  • Lee, Chang-Hyun;Kim, Sang-Youp;Kim, Jai-Sung
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.13 no.4
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    • pp.73-85
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    • 2014
  • Approaching to aging society with increasing transportation vulnerable, most developed countries has positively promote low-floor bus. Such circumstance in Korea has plan to introduce low-floor bus to intra-city bus system which accounted for 30 percent of total number of buses however there is no specific operating plan for this matter. According to the revealed preference study on bus service, the study shows that the efficiency of low-floor is relatively low than that of other buses, therefore, it is necessary to establish feasible plan for bus route selection. Thus, this study is to conduct research on analyzing trip characteristics of transportation vulnerable and establish bus route selection measures for low-floor bus. The result from the survey in Jeollabuk-do Province reveals that the trip purpose of transportation vulnerable is mainly for welfare and medical service, which was made less than 6 times a week. Futhermore, 37.6 percent of transportation vulnerable use buses, thus, it is essential to improve its service quality for enhancing user's convenience and safety. In that transportation vulnerable O-D needs to be established and forecasts future demand for selecting optimal bus route. According to the estimation, route passing through densely populated areas with transportation vulnerable should take the first priority, city circular and other route would be next. Moreover, it is economically efficient that areas populated more than 200,000 with fixed route and less than 200,000 with limited route responsive to demands would be feasible plans. This study will have greater an impact on transportation planning and further research on transportation vulnerable.

Development of Korean NOVA Food Classification and Estimation of Ultra-Processed Food Intake Among Adults: Using 2018 Korea National Health and Nutrition Examination Survey (한국형 NOVA 식품분류체계의 개발 및 한국 성인의 초가공식품 섭취량 추정: 2018년 국민건강영양조사 자료를 활용하여)

  • Hae Jin, Park;Sohyun, Park;Jee Young, Kim
    • Korean Journal of Community Nutrition
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    • v.27 no.6
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    • pp.455-467
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    • 2022
  • Objectives: In this study, we suggest a Korean NOVA food classification that can be applied to food consumption among Korean. Based on this suggestion, the nutritional intake of Korean adults from ultra-processed foods (UPFs) was estimated. Methods: Korean commercial food was categorized based on the NOVA food classification criteria through the Korea Food Code and expert meetings. Then, the nutrient intake status of 6,991 participants in the 2018 National Health and Nutrition Examination Survey was analyzed according to the food processing level. Then, 4,152 adult participants (age 19-65) were divided into quartiles on the basis of their intake of UPFs, and the nutrient intakes from UPFs were compared. Results: Korean NOVA Food Classification defines with priority Group I (Unprocessed/ Minimally processed foods) and Group II (Processed culinary ingredients) foods based on the food cooking or consumption. Then, Group III (Processed foods) and Group IV (UPFs) are classified according to whether the characteristics of the raw materials used are maintained or whether the food was consumed before the 1970s. Our analysis results showed that most of the calories in the diet were consumed by Group I (52.7%), followed by Group IV (29.3%). After categorization of the adult participants into four groups according to their energy consumption from UPFs, we found that the highest consumption group (Q4) was younger and had higher percentage of men than women. The comparative analysis of the consumption of ultra-processed foods by Korean adults revealed that participants of a younger age and men consumed higher energy from UPFs than older participants and women, respectively (P < 0.01). Furthermore, the larger intake of UPFs was associated with an increasing trend for a higher intake of energy, sugar, saturated fat (P for trend < 0.001), total fat (P for trend = 0.021), and sodium (P for trend = 0.005), whereas the intake of carbohydrate, protein, and dietary fiber had a decreasing trend (P for trend < 0.001). Conclusions: With the current increase in the consumption of processed and ultra-processed foods, it is important to carefully consider not only nutrient intake but also the level of food processing.

Financial Products Recommendation System Using Customer Behavior Information (고객의 투자상품 선호도를 활용한 금융상품 추천시스템 개발)

  • Hyojoong Kim;SeongBeom Kim;Hee-Woong Kim
    • Information Systems Review
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    • v.25 no.1
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    • pp.111-128
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    • 2023
  • With the development of artificial intelligence technology, interest in data-based product preference estimation and personalized recommender systems is increasing. However, if the recommendation is not suitable, there is a risk that it may reduce the purchase intention of the customer and even extend to a huge financial loss due to the characteristics of the financial product. Therefore, developing a recommender system that comprehensively reflects customer characteristics and product preferences is very important for business performance creation and response to compliance issues. In the case of financial products, product preference is clearly divided according to individual investment propensity and risk aversion, so it is necessary to provide customized recommendation service by utilizing accumulated customer data. In addition to using these customer behavioral characteristics and transaction history data, we intend to solve the cold-start problem of the recommender system, including customer demographic information, asset information, and stock holding information. Therefore, this study found that the model proposed deep learning-based collaborative filtering by deriving customer latent preferences through characteristic information such as customer investment propensity, transaction history, and financial product information based on customer transaction log records was the best. Based on the customer's financial investment mechanism, this study is meaningful in developing a service that recommends a high-priority group by establishing a recommendation model that derives expected preferences for untraded financial products through financial product transaction data.

Developing a Traffic Accident Prediction Model for Freeways (고속도로 본선에서의 교통사고 예측모형 개발)

  • Mun, Sung-Ra;Lee, Young-Ihn;Lee, Soo-Beom
    • Journal of Korean Society of Transportation
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    • v.30 no.2
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    • pp.101-116
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    • 2012
  • Accident prediction models have been utilized to predict accident possibilities in existing or projected freeways and to evaluate programs or policies for improving safety. In this study, a traffic accident prediction model for freeways was developed for the above purposes. When selecting variables for the model, the highest priority was on the ease of both collecting data and applying them into the model. The dependent variable was set as the number of total accidents and the number of accidents including casualties in the unit of IC(or JCT). As a result, two models were developed; the overall accident model and the casualty-related accident model. The error structure adjusted to each model was the negative binomial distribution and the Poisson distribution, respectively. Among the two models, a more appropriate model was selected by statistical estimation. Major nine national freeways were selected and five-year dada of 2003~2007 were utilized. Explanatory variables should take on either a predictable value such as traffic volumes or a fixed value with respect to geometric conditions. As a result of the Maximum Likelihood estimation, significant variables of the overall accident model were found to be the link length between ICs(or JCTs), the daily volumes(AADT), and the ratio of bus volume to the number of curved segments between ICs(or JCTs). For the casualty-related accident model, the link length between ICs(or JCTs), the daily volumes(AADT), and the ratio of bus volumes had a significant impact on the accident. The likelihood ratio test was conducted to verify the spatial and temporal transferability for estimated parameters of each model. It was found that the overall accident model could be transferred only to the road with four or more than six lanes. On the other hand, the casualty-related accident model was transferrable to every road and every time period. In conclusion, the model developed in this study was able to be extended to various applications to establish future plans and evaluate policies.

A Contemplation on Measures to Advance Logistics Centers (물류센터 선진화를 위한 발전 방안에 대한 소고)

  • Sun, Il-Suck;Lee, Won-Dong
    • Journal of Distribution Science
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    • v.9 no.1
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    • pp.17-27
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    • 2011
  • As the world becomes more globalized, business competition becomes fiercer, while consumers' needs for less expensive quality products are on the increase. Business operations make an effort to secure a competitive edge in costs and services, and the logistics industry, that is, the industry operating the storing and transporting of goods, once thought to be an expense, begins to be considered as the third cash cow, a source of new income. Logistics centers are central to storage, loading and unloading of deliveries, packaging operations, and dispensing goods' information. As hubs for various deliveries, they also serve as a core infrastructure to smoothly coordinate manufacturing and selling, using varied information and operation systems. Logistics centers are increasingly on the rise as centers of business supply activities, growing beyond their previous role of primarily storing goods. They are no longer just facilities; they have become logistics strongholds that encompass various features from demand forecast to the regulation of supply, manufacturing, and sales by realizing SCM, taking into account marketability and the operation of service and products. However, despite these changes in logistics operations, some centers have been unable to shed their past roles as warehouses. For the continuous development of logistics centers, various measures would be needed, including a revision of current supporting policies, formulating effective management plans, and establishing systematic standards for founding, managing, and controlling logistics centers. To this end, the research explored previous studies on the use and effectiveness of logistics centers. From a theoretical perspective, an evaluation of the overall introduction, purposes, and transitions in the use of logistics centers found issues to ponder and suggested measures to promote and further advance logistics centers. First, a fact-finding survey to establish demand forecast and standardization is needed. As logistics newspapers predicted that after 2012 supply would exceed demand, causing rents to fall, the business environment for logistics centers has faltered. However, since there is a shortage of fact-finding surveys regarding actual demand for domestic logistic centers, it is hard to predict what the future holds for this industry. Accordingly, the first priority should be to get to the essence of the current market situation by conducting accurate domestic and international fact-finding surveys. Based on those, management and evaluation indicators should be developed to build the foundation for the consistent advancement of logistics centers. Second, many policies for logistics centers should be revised or developed. Above all, a guideline for fair trade between a shipper and a commercial logistics center should be enacted. Since there are no standards for fair trade between them, rampant unfair trades according to market practices have brought chaos to market orders, and now the logistics industry is confronting its own difficulties. Therefore, unfair trade cases that currently plague logistics centers should be gathered by the industry and fair trade guidelines should be established and implemented. In addition, restrictive employment regulations for foreign workers should be eased, and logistics centers should be charged industry rates for the use of electricity. Third, various measures should be taken to improve the management environment. First, we need to find out how to activate value-added logistics. Because the traditional purpose of logistics centers was storage and loading/unloading of goods, their profitability had a limit, and the need arose to find a new angle to create a value added service. Logistic centers have been perceived as support for a company's storage, manufacturing, and sales needs, not as creators of profits. The center's role in the company's economics has been lowering costs. However, as the logistics' management environment spiraled, along with its storage purpose, developing a new feature of profit creation should be a desirable goal, and to achieve that, value added logistics should be promoted. Logistics centers can also be improved through cost estimation. In the meantime, they have achieved some strides in facility development but have still fallen behind in others, particularly in management functioning. Lax management has been rampant because the industry has not developed a concept of cost estimation. The centers have since made an effort toward unification, standardization, and informatization while realizing cost reductions by establishing systems for effective management, but it has been hard to produce profits. Thus, there is an urgent need to estimate costs by determining a basic cost range for each division of work at logistics centers. This undertaking can be the first step to improving the ineffective aspects of how they operate. Ongoing research and constant efforts have been made to improve the level of effectiveness in the manufacturing industry, but studies on resource management in logistics centers are hardly enough. Thus, a plan to calculate the optimal level of resources necessary to operate a logistics center should be developed and implemented in management behavior, for example, by standardizing the hours of operation. If logistics centers, shippers, related trade groups, academic figures, and other experts could launch a committee to work with the government and maintain an ongoing relationship, the constraint and cooperation among members would help lead to coherent development plans for logistics centers. If the government continues its efforts to provide financial support, nurture professional workers, and maintain safety management, we can anticipate the continuous advancement of logistics centers.

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Clinicopathologic and Epidemiologic Study of Childhood Nephrotic Syndrome in Taejon, Korea (대전지역 소아 신증후군의 임상병리학적 및 역학적 연구)

  • Yim Sam-Hwa;Yoon Kye-Nam;Cha Sang-Won;Lee Dong-Joon;Han Ji-Whan;Whang Kyung-Tae;Lee Kyung-Yil
    • Childhood Kidney Diseases
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    • v.3 no.2
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    • pp.145-152
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    • 1999
  • Purpose: The prevalence of childhood renal diseases including the nephrotic syndrome in Korea has not been well established. In priority to this point, we analyzed ninety-six nephrotic children of the annual incidence, the ratio of them to all inpatients and estimated incidence of childhood nephrotic syndrome under 15 years of age in Taejon, Korea. Also we classified them by clinical and histopathological findings. Methods: we analyzed the admission and outpatient records retrospectively between June 1986 and December 1998. For the estimation of incidence, we were assisted with three other general hospitals in Taejon Results: The mean annual number and the ratio to inpatients were $7.4{\pm}2.1,\;0.3{\pm}0.11%$ respectively. The latter showed a tendency to decrease during the recent three years. The estimated annual incidences of childhood nephrotic syndrome in Taejon were 5.6 in 1988, 5.5 in 1993 and 4.8 in 1998 per 100,000 for children aged up to 15 years. The mean age of our patients was $6.8{\pm}3.5$ tears, 1-7 years of age was 55 cases(57.3%), and male to female ratio was 3.6:1. By the clinicopathologic classification, 89 cases(92.7%) were classified as primary nephrotic syndrome, and 7 cases(7.3%) as secondary nephrotic syndrome. Among the primary nephrotic syndrome, there was 79.8% of minimal change nephrotic syndrome, focal segmental glomerulosclerosis 11.2%, mesangial proliferation 4.5%, membranoproliferative glomerulonephritis 3.4%, and membranous nephropathy 1.1%. $Henoch-Sch\"{o}nlein$ nephritis was the most frequent of 3 cases in the secondary nephrotic syndrome. Respones to steroid therapy of 71 cases minimal change were classified as non-relapse 22.5%, non-frequent relapse 49.3%, frequent relapse 18.3% and steroid-dependence 9.9%. Conclusion: The estimated incidence of childhood nephrotic syndrome was about 5 per 100,000 for children aged up to 15 years and it showed little changes during 10 years in Taejon, Korea. Our results of clinicopathologic study was little difference from the results reported in other literatures.

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Analysis of PAHs (polycyclic aromatic hydrocarbons) in Ground Coffee Using GC-tandem Mass Spectrometry and Estimation of Daily Dose (GC-tandem mass spectrometry를 이용한 분쇄원두커피 중 PAHs(polycyclic aromatic hydrocarbons) 분석법 연구 및 인체노출량 평가)

  • Jung, So-Young;Park, Ju-Sung;Son, Yeo-Joon;Choi, Su-Jeong;Lee, Yun-Jeong;Kim, Mi-Sun;Park, So-Hyun;Lee, Sang-Me;Chae, Young-Zoo
    • Korean Journal of Food Science and Technology
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    • v.43 no.5
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    • pp.544-552
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    • 2011
  • The purpose of this study was to develop an analytical method for determining 15 polycyclic aromatic hydrocarbons (PAHs) of EU priority using gas chromatography (GC)-tandem mass spectrometry (MS). The PAHs in ground coffee were analyzed after being extracted using methods such as saponification-liquid-liquid extraction, Soxhlet extraction, and solid-liquid extraction. The solid-liquid extraction method showed the greatest repeatability and most efficient reduction of the matrix effect. GC-tandem MS for the quantification of the 15 PAHs showed better resolution and lower limit of detections (LODs) than GC-MS-selected ion monitoring (SIM) and high performance liquid chromatography with fluorescence detector. LODs of this method for the ground coffee types were 0.002-0.1 ${\mu}g/kg$ and limit of quantifications (LOQs) were 0.006-0.2 ${\mu}g/kg$ The recoveries ranged from 52.6 to 93.3%. Forty-six commercial types of ground coffee were analyzed to determine their PAHs contamination levels. PAHs concentration ranged from ND to 5.988 ${\mu}g/kg$. This study was conducted with toxicity equivalence factors, the U.S. EPA recommendation to identify dietary risks for PAHs in different types of coffee. The estimated average daily dose of PAHs was $5.24{\times}10^{-8}$ mg/kg body weight/day.