• Title/Summary/Keyword: Traffic Distribution

Search Result 1,022, Processing Time 0.03 seconds

A Study on the Domestic Small Package Express Service′s Competitive Power Improvement Plan at EC Times (전자상거래 시대 국내 택배업의 경쟁력 향상 방안에 관한 연구)

  • 박영태;정종식
    • Proceedings of the Korean DIstribution Association Conference
    • /
    • 2002.05a
    • /
    • pp.31-59
    • /
    • 2002
  • Recently there are many changes of logistics environment Such as integrated logistics information system, the rapid growth of the domestic and international small package express service and third party logistics with Electronic Commerce. At this time it is very important to deliver to customers the goods sold through EC speedy, accurately and safely. That is to say, the role of small package express service is very important at EC times. The bottlenecks of small package express service in the circumstances of EC are the weakness of EC operating company and small package express service provider the shortage of distribution centre and cargo terminal, the shortage of skilled man with related small package express service etc. So, I suggested that for activation of EC it is necessary to strengthen the strategic alliances, introduce GPS and use the third party logistics positively in the side of small package express service provider. And it is necessary to prepare for the settlements of traffic problems, support the introduction of integrated logistics service, logistics information system, deregulate restriction such as weight limit of vehicles in the side of the government. And to government support throughout extending nation's SOC, deregulation, support to small package express service terminal, permit to stopping & parking in downtown, abolishing a no passing zone, permit to being employed foreigner. Also this service involves ensuring that the product will arrive when wanted, and in an undamaged condition.

  • PDF

Analysis on Social Area of Taegu (대구시의 사회지역분석)

  • Choi, Seok-Joo
    • Journal of the Korean association of regional geographers
    • /
    • v.3 no.2
    • /
    • pp.209-225
    • /
    • 1997
  • Today, rapid progress of urbanization is discovered commonly in many countries, especially in developing countries, which has led to spatial order and development process of city. Historically, Taegu was a walled city and formed mono-nucleus which was restricted by the castle. As the city grew gradually, the castle was removed as a result of diversification in traffic network, change of socio-economic environment, formation of industrial base and functional distribution. According to reconstruction maps of residential patterns, there was distinctive residential segregation among ethnic groups. Koreans in Taegu in 1939, aggregated densely in the southern and western parts of the city. The Japanese were concentrated densely in the northern and eastern parts of Taegu. And the street pattern within residential areas of the Korean people was shaped like a maze type in contrast with Japanese residential areas, which showed grid pattern of streets. This is another general pattern of almost all colonial cities, especially in Asia. Through this process, today it appears that, out of overall residential areas which occupy the highest ratio in urban land use, those for eminent people influence the functional development of urban spatial structure very heavily as a key point in urban residetial structure. Truly, residential segregation can be seen as the spatial manifestation of uneven distribution of such important scarce resources as housing and residential environment. In this study, the characteristics of locational distribution of the eminent people show their socially and economically stabilized standing in Taegu, taking the aforesaid situation as a background of the study. And the process of this study is as follows ; to examine the forming process of residential areas in the city as a theoretical supporting, to put in order on classical interpretation to formation of residential areas, and general type modern residential areas formation, and economic decision factor of land use. Therefore, this study aims to examine growth and development of eminent persons' residential areas and, at the same time, extract locational characteristics through the pattern of eminent persons' location and predict changes in the future.

  • PDF

Real Option Analysis to Value Government Risk Share Liability in BTO-a Projects (손익공유형 민간투자사업의 투자위험분담 가치 산정)

  • KU, Sukmo;LEE, Sunghoon;LEE, Seungjae
    • Journal of Korean Society of Transportation
    • /
    • v.35 no.4
    • /
    • pp.360-373
    • /
    • 2017
  • The BTO-a projects is the types, which has a demand risk among the type of PPP projects in Korea. When demand risk is realized, private investor encounters financial difficulties due to lower revenue than its expectation and the government may also have a problem in stable infrastructure operation. In this regards, the government has applied various risk sharing policies in response to demand risk. However, the amount of government's risk sharing is the government's contingent liabilities as a result of demand uncertainty, and it fails to be quantified by the conventional NPV method of expressing in the text of the concession agreement. The purpose of this study is to estimate the value of investment risk sharing by the government considering the demand risk in the profit sharing system (BTO-a) introduced in 2015 as one of the demand risk sharing policy. The investment risk sharing will take the form of options in finance. Private investors have the right to claim subsidies from the government when their revenue declines, while the government has the obligation to pay subsidies under certain conditions. In this study, we have established a methodology for estimating the value of investment risk sharing by using the Black - Scholes option pricing model and examined the appropriateness of the results through case studies. As a result of the analysis, the value of investment risk sharing is estimated to be 12 billion won, which is about 4% of the investment cost of the private investment. In other words, it can be seen that the government will invest 12 billion won in financial support by sharing the investment risk. The option value when assuming the traffic volume risk as a random variable from the case studies is derived as an average of 12.2 billion won and a standard deviation of 3.67 billion won. As a result of the cumulative distribution, the option value of the 90% probability interval will be determined within the range of 6.9 to 18.8 billion won. The method proposed in this study is expected to help government and private investors understand the better risk analysis and economic value of better for investment risk sharing under the uncertainty of future demand.

Changes of Street Patterns in Central Part of Taegu City (大邱市 都心部의 街路網 變化)

  • Choi, Seok-Joo
    • Journal of the Korean Geographical Society
    • /
    • v.31 no.3
    • /
    • pp.593-612
    • /
    • 1996
  • This study concern with the changes of street from the Choseon Dynasty to present days around Old-Boundary in Taegu, analyzing the backgrounds of change factors and development trends of the Taegu City. The basis element of a city structure is the street. Therefore, in this study, a chage of street space of a city was investigted. Historically, Taegu was a walled city and had a Mono-nucleus which was restricted by the castle, and served as a starting point of formation of spatial structuure. The form of the artery street took a "T" pattern, othe streets were formed in irregular shapes. As the city grew gradually, the castle was removed on account of diversification in traffic network, change of socio-economic organization in traffic network, change of socio-economic organization, formation of industrial bases and functional distribution. CBD of this city has been located within the area surrounded by these streets. This is a kind of general pattern of traditional walled cities through the world in both Western and Oriental societies. A s the begining of this centry, a 'Dark Ages' descended upon Korea because the country was under the Japanese-Korean Annexation, and, throughout this period, the urban planning was planned exclusively for Japanese. The street pattern within residential areas of Korea took the maze type, in contrast with Japanese residential areas which showed grid pattern of streets. This is another general pattern of almost of all colonial cities especially in Asia. High class residential areas were planned and built by Japanese, and they were located within 5-10 minutes' on-foot distance from the CBD hard core. This high prestige has continued until the 1980s when it occurred land use succession which commerical functions invaded into residential areas. Back in the colonial period, there was a between two hetrogeneous groups due to the fact that the Japanese lived mainly oriented the new railway system but that Koreans still lived along the old highway system which ran through the Korea Peninsula. Street netwook formed in the above process has maintained its shape without great changes after the liberation form the Japanese Colony. Taegu has, accordingly, developed ring-radial network system which has been a combination of radial and ring facilities. The present conditions of street patterns in Taegy mainly depend on 4 rings and 8 radius, with grid pattern street able to be found in Old Boundary.

  • PDF

Continuous Nearest Neighbor Query Processing on Trajectory of Moving Objects (이동객체의 궤적에 대한 연속 최근접 질의 처리)

  • 지정희;최보윤;김상호;류근호
    • Journal of KIISE:Databases
    • /
    • v.31 no.5
    • /
    • pp.492-504
    • /
    • 2004
  • Recently, as growing of interest for LBS(location-based services) techniques, lots of works on moving objects that continuously change their information over time, have been performed briskly. Also, researches for NN(nearest neighbor) query which has often been used in LBS, are progressed variously However, the results of conventional NN Query processing techniques may be invalidated as the query and data objects move. Therefore, they are usually meaningless in moving object management system such as LBS. To solve these problems, in this paper we propose a new nearest neighbor query processing technique, called CTNN, which is possible to meet accurate and continuous query processing for moving objects. Our techniques include an Approximate CTNN(ACTNN) technique, which has quick response time, and an Exact CTNN(ECTNN) technique, which makes it possible to search nearest neighbor objects accurately. In order to evaluate the proposed techniques, we experimented with various datasets. Experimental results showed that the ECTNN technique has high accuracy, but has a little low performance for response time. Also the ACTNN technique has low accuracy comparing with the ECTNN, but has quick response time The proposed techniques can be applied to navigation system, traffic control system, distribution information system, etc., and specially are most suitable when both data and query are moving objects and when we already know their trajectory.

Current Conditions of Habitat for Rana catesbeiana and Trachemys scripta elegans Imported to Jeju-do, Including Proposed Management Plans (제주도에 이입된 황소개구리(Rana catesbeiana)와 붉은귀거북(Trachemys scripta elegans)의 서식실태 및 관리방안)

  • Oh, Hong-Shik;Hong, Chang-Eui
    • Korean Journal of Environment and Ecology
    • /
    • v.21 no.4
    • /
    • pp.311-317
    • /
    • 2007
  • This study was conducted to determine the geographical distribution and habitat for Rana catesbeiana and Trachemys scripta elegans in order to obtain the current basic data on biota needed for establishing a database on non-indigenous species(NIS) in Jeju-do and to develop management plans applicable to Jeju, starting from March 2005 until May 2006. As a result of an inspection, it was found that the habitat for R. catesbeiana in Jeju includes Hankyeong-myeon, Daejeong-eup, and Ahndeok-myeon. These areas are all located on the western side of Jeju-do, and considered to have favorable conditions for R. catesbeiana to inhabit. Thus, it is unlikely that the population of R. catesbeiana will possibly decrease; what's worse, there exists even a risk that it could not only expand to other regions but also do damage to the population of native insecta, fishes, amphibians and reptiles, so this terrible species ought to be exterminated. More than 92 individuals of T. scripta elegans species were found to inhabit in 15 ponds around Jeju Island. T. scripta elegans. as the topmost predator, could destruct the pond ecosystem, and also cause a problem of water pollution due to its excrement. Counter-measures against T. scripta elegans could include publicity activities encouraging self-control of the release of captive T. scripta elegans, extermination plans using its ecological habits, and sign-posting publicizing its hazard to healthy ecosystem at the areas with high population density of T. scripta elegans or at its habitats with high foot traffic, together with the continuous management of NIS(none-indigenous species).

Estimation of Gas-particle partitioning Coefficients (Kp) of Carcinogenic polycyclic Aromatic hydrocarbons in Carbonaceous Aerosols Collected at Chiang - Mai, Bangkok and hat-Yai, Thailand

  • Pongpiachan, Siwatt;Ho, Kin Fai;Cao, Junji
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.14 no.4
    • /
    • pp.2461-2476
    • /
    • 2013
  • To assess environmental contamination with carcinogens, carbonaceous compounds, water-soluble ionic species and trace gaseous species were identified and quantified every three hours for three days st three different atmospheric layer at the heart of chiang-Mai, bangkok and hat-Yai from December 2006 to February 2007. A DRI model 2001 Themal/Optical Carbon Analyzer with the IMPROVE thermal/optical reflectance (TOR) protocol was used to quantify the organic carbon(OC) and elemental carbon content in $PM_{10}$. Diurnal and vertical variability was also carefully investigated. In general, OC and EC contenttration shoeed the highest values at the monitoring period o 21.00-00.00 as consequences of human activities at night bazaar coupled with reduction of mixing layer, decreased wind speed and termination of photolysis nighttime. Morning peaks of carboaceous compounds were observed during the sampling period of 06:00 -09:00, emphasizing the main contribution of traffic emission in the three cities. The estimation of incremental lifetime partculate matter exposure (ILPE) raises concern of high risk of carbonaceous accumulation over workers and residents living close to the observatory sites. The average values of incremental lifrtime particulate matter exposure (ILPE) of total carbon at Baiyoke Suit Hotel and Baiyoke Sky Hotel are approsimately ten time shigher then those air sample collected at prince of songkla University Hat-Yai campus corpse incinerator and fish-can maufacturing factory but only slightly higher than those of rice straw burnig in Songkla province. This indicates a high risk of developing lung cancer and other respiratory diseases across workers and residents living in high buildings located in Pratunam area. Using knowledge of carbonaceous fractions in $PM_{10}$, one can estimate the gas-particle partitioning of polycyclic aromatic hydrocarbons (PAHs). Dachs-Eisenreich model highlights the crucial role of adsorption in gas-particle partitioning of low molecular weight PAHs, whereas both absorption and adsorption tend to account for gas-particle partitioning of high molecular weight PAHs in urban residential zones of Thailand. Interestingly, the absorption mode alone plays a minor role in gas-partcle partitiining of PAHs in Chiang-Mai, Bangkok and hat-Yai.

Sources of Carbonaceous Materials in the Airborne Particulate Matter of Dhaka

  • Begum, Bilkis A.;Hossain, Anwar;Saroar, Golam;Biswas, Swapan K.;Nasiruddin, Md.;Nahar, Nurun;Chowdury, Zohir;Hopke, Philip K.
    • Asian Journal of Atmospheric Environment
    • /
    • v.5 no.4
    • /
    • pp.237-246
    • /
    • 2011
  • To explore the sources of carbonaceous material in the airborne particulate matter (PM), comprehensive PM sampling was performed (3 to 14 January 2010) at a traffic hot spot site (HS), Farm Gate, Dhaka using several samplers: AirMetrics MiniVol (for $PM_{10}$ and $PM_{2.5}$) and MOUDI (for size fractionated submicron PM). Long-term PM data (April 2000 to March 2006 and April 2000 to March 2010 in two size fractions ($PM_{2.2}$ and $PM_{2.2-10}$) obtained from two air quality-monitoring stations, one at Farm Gate (HS) and another at a semi-residential (SR) area (Atomic Energy Centre, Dhaka Campus, (AECD)), respectively were also analyzed. The long-term PM trend shows that fine particulate matter concentrations have decreased over time as a result of government policy interventions even with increasing vehicles on the road. The ratio of $PM_{2.5}/PM_{10}$ showed that the average $PM_{2.5}$ mass was about 78% of the $PM_{10}$ mass. It was also found that about 63% of $PM_{2.5}$ mass is $PM_1$. The total contribution of BC to $PM_{2.5}$ is about 16% and showed a decreasing trend over the years. It was observed that $PM_1$ fractions contained the major amount of carbonaceous materials, which mainly originated from high temperature combustion process in the $PM_{2.5}$. From the IMPROVE TOR protocol carbon fraction analysis, it was observed that emissions from gasoline vehicles contributed to $PM_1$ given the high abundance of EC1 and OC2 and the contribution of diesel to $PM_1$ is minimal as indicated by the low abundance of OC1 and EC2. Source apportionment results also show that vehicular exhaust is the largest contributors to PM in Dhaka. There is also transported $PM_{2.2}$from regional sources. With the increasing economic activities and recent GDP growth, the number of vehicles and brick kilns has significantly increased in and around Dhaka. Further action will be required to further reduce PM-related air pollution in Dhaka.

A Study on the Triage and Statitical Data of Patients in the Emergency Room, PNU (일 종합병원 응급실 이용환자의 중증도 분류)

  • 김영혜;이화자;조석주
    • Journal of Korean Academy of Nursing
    • /
    • v.31 no.1
    • /
    • pp.68-80
    • /
    • 2001
  • The purpose of this study is to analyze ER patient's Triage and other statistical data. The subjects were 12,618 patients who visited the ER during the year 1998. The study showed the following results; 1. The male vs female ratio was 1.3 : 1.0, the male were in the majority (56.6%), and the age range of 20-29 old was the majority (15.3). The patients who visited ER at 8-10 pm were the majority (11.5%). On Sunday the number of patients who visited the ER were 2,189, and the majority were 17.4%. On Saturday the number of patients was visited the ER were 1,944 patients the second majority (15.4%). Their traffic means : the general passenger cars (75.5%), 119 or hospital ambulance (11.3%). 2.The reasons of visiting ER were : diseases (59.2%), injuries (23.7%). The disease vs injury ratio was 100 : 69. 3. Triage : urgent 40.7%, non-urgent 38.2%, acute 17.8%, and critical 3.2%. 4. The time of waiting and staying in the ER by the Triaget: the average time was 572 minutes (9.53 hrs.). The majority of critical patients (20.5%), acute patients (24.7%) and urgent patients (21.2%) stayed 12-24 hrs., but the majority of non-emergent (27.8%) stayed not longer than one hour. 5. Treatments by the Triage : the 42.9% of critical patients, and 61.3% of acute patients, 57.5% of urgent patients were admitted. But 91.8% of the non-emergents were discharged and 4.7% was admitted. Mortality of total ER visiter were 1.7%. DAA portion was 0.86%. 26.6% of the critical patients were DAA. DAA vs DOA ratio was 1.3 : 1.0. 6. Visiting time, monthly and seasonal distribution by the Triage : the majority of critical patients (12.2%), visited 10-12 am. The majority of acute (12.9%) and urgent (11.7%) visited 4-6 pm, but the majority of non-emergents (15.1%) visited during 8-10 pm. Autumn visiter were the majority (27.6%). The percentage of non-emergent visited in Spring was 41.4% and Autumn was 41.3%. The percentage of urgents who visited in the Summer was 45.3% and the Winter was 40.4%. By clinical departments: the 48.0% of critical patients was NS. The 45.5% of acute and the 33.6% of urgent patients were IM. But the majority of non-emergent patients was PS (21.2%), and the second majority of non-emergent patients was oral Surgery (12.8%).

  • PDF

A Crash Prediction Model for Expressways Using Genetic Programming (유전자 프로그래밍을 이용한 고속도로 사고예측모형)

  • Kwak, Ho-Chan;Kim, Dong-Kyu;Kho, Seung-Young;Lee, Chungwon
    • Journal of Korean Society of Transportation
    • /
    • v.32 no.4
    • /
    • pp.369-379
    • /
    • 2014
  • The Statistical regression model has been used to construct crash prediction models, despite its limitations in assuming data distribution and functional form. In response to the limitations associated with the statistical regression models, a few studies based on non-parametric methods such as neural networks have been proposed to develop crash prediction models. However, these models have a major limitation in that they work as black boxes, and therefore cannot be directly used to identify the relationships between crash frequency and crash factors. A genetic programming model can find a solution to a problem without any specified assumptions and remove the black box effect. Hence, this paper investigates the application of the genetic programming technique to develope the crash prediction model. The data collected from the Gyeongbu expressway during the past three years (2010-2012), were separated into straight and curve sections. The random forest technique was applied to select the important variables that affect crash occurrence. The genetic programming model was developed based on the variables that were selected by the random forest. To test the goodness of fit of the genetic programming model, the RMSE of each model was compared to that of the negative binomial regression model. The test results indicate that the goodness of fit of the genetic programming models is superior to that of the negative binomial models.