• Title/Summary/Keyword: traffic conditions

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A Study on the competitive status and cooperative schemes of Korea-China ports (한·중 항만의 경쟁실태와 협력 방안)

  • Kim, Hong-seop
    • Journal of Distribution Science
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    • v.5 no.2
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    • pp.55-78
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    • 2007
  • Northeast Asia is one of the regions which have been developing so rapidly. Yellow sea, located between Korea and China, became a very important logistical zone because of its huge volume of cargo and big passenger traffic. These two countries continuously are enlarging their port facilities such as berths, container yards, storage capacity and their information system in this the Pan Yellow sea area. Two countries also introduce many new liner routes and car-ferry shipping services. Therefore there must be a severe competitions and conflicts among the countries and their companies and ports as well. Some experts worry about the over capacity of port and logistics facilities. This paper investigated the current conditions of Korea-China shipping route, container and car-ferry route, and found out the problems and tasks, with the support of many experts. There are so many alternatives and strategies to solve and rationalize the shipping route and the problems of ports of two countries. This paper suggest many strategies connecting with marketing 4Ps. As port service is also a kind of service product, we can categorize the strategies into 4Ps suggested by McCarthy. And this paper classify all these alternatives into 3 dimensions. There are competitive strategies, cooperative strategies and coopetition strategies. This paper propose some directions and ideas for adopting the strategy in the port and logistical topics between Korea and China, suggesting 3 dimensions of strategies. After this paper, many diagnoses and practical investigations should be executed to introduce optimal solutions and minimize the additional cost.

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A Study on Dose Reduction in Infant Skull Radiography (유아 두개골 방사선촬영에서 피폭선량 감쇄에 관한 연구)

  • Ahn, Byoung-Ju
    • Journal of the Korean Society of Radiology
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    • v.11 no.5
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    • pp.387-392
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    • 2017
  • When an infant has visited a hospital due to skull fracture, the rupture of a blood vessel, or skin wounds on the head resulted from an incident, accident, traffic accident, or disease, he/she becomes to undergo anterior/posterior and lateral skull imaging, which is a head test at the department of radiology. In the head test, if the adult skull imaging grid is applied to the imaging, the secondary radiation will be removed to enhance the contrast of the image. However, among the radiation exposure conditions, the tube voltage should be enhanced by 8~10 kVp leading to an increase in the patient exposure. The present study was conducted under assumption that if the same images can be obtained from infant skull imaging without using the skull imaging grid, the exposure dose will be reduced and the artifacts due to grid cut off can be prevented. The researcher measured the radiation dosage using a radiation meter and conducted the subjective evaluation (ROC, receiver operating characteristic) among medical image evaluation methods. Based on the results, when the images were taken without using the grid, the exposure dose was reduced by 0.019 mGy in the anterior/posterior imaging and by 0.02 mGy in the lateral imaging and the image evaluation score was higher by 4 points. In conclusion, if the images of the skulls of infants that visited the hospital are taken with out using the grid, the exposure dose can be reduced, the image artifacts due to grid cut off can be prevented, and the lifespan of the X-ray tube will be extended.

The Relationship between the Prevalence of Allergic Diseases and Urinary Cadmium Concentrations among School-age Children in Two Regions in Ulsan Metropolitan City (울산의 두 지역 초등학생의 알레르기 질환 유병과 요중 카드뮴 농도와의 관련성)

  • Kim, Ahra;Hong, Young-Seoub;Bang, Jin-Hee;Oh, Inbo;Chung, Jin-Young;Sim, Chang Sun;Lee, Hyun Jin;Kim, Yangho;Lee, Jiho
    • Journal of Environmental Health Sciences
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    • v.42 no.6
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    • pp.396-408
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    • 2016
  • Objectives: The purposes of this study were to determine the relationship between the prevalence of allergic diseases and urinary cadmium concentration among children from six to 12 years of age, and to evaluate the association between cadmium in urine and other immunologically related factors in two elementary schools with different environmental conditions. Methods: Data on physician-diagnosed prevalence over the past 12 months and potential risk factors for allergic disease were collected from survey results drawn from 236 children living in different regions (central urban vs. suburban) from April to July in 2014 by an ISAAC questionnaire. We analyzed cytokine levels in serum through enzyme-linked immunosorbent assay and urinary cadmium concentration by use of inductively coupled plasma mass spectrometry. Results: Concentrations of urinary cadmium in suburban and central urban children were $0.11{\pm}0.11ug/L$, $0.14{\pm}0.17ug/L$, respectively (p>0.05). Results from the analysis of the t-test and chi-square test showed that urinary cadmium levels were positively associated with environmental factors (paternal smoking status, passive smoking, traffic volume and experiences of outdoor odors) and individual genetic factors (parental allergic disease). Cadmium concentrations in urine were also positively associated with the prevalence of allergic disease and immune-related cytokines (eosinophils, IgE, IL-5, IL-33, IL-17). Conclusion: This study suggests that genetic factors (parental history of allergic diseases), environmental factors, and regional status (suburban and central urban) should be considered as probable factors increasing the concentration of urinary cadmium, which has the potential to influence the allergic disease prevalence of school-age children.

Development of Moisture Loss Index Based on Field Moisture Measurement using Portable Time Domain Reflectometer (TDR) for Cold In-place Recycled Pavements (휴대용 TDR 함수량계로 측정한 현장 함수비를 이용한 현장 상온 재활용 아스팔트 포장의 수분 감소계수 개발)

  • Kim, Yong-Joo;Lee, Ho-Sin David;Im, Soo-Hyok
    • International Journal of Highway Engineering
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    • v.13 no.2
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    • pp.139-145
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    • 2011
  • The practice of asphalt pavement recycling has grown rapidly over the decade, one of which is the cold in-place recycling with the foamed asphalt (CIR-foam) or the emulsified asphalt (CIR-emulsion). Particularly, in Iowa, the CIR has been widely used in rehabilitating the rural highways because it significantly increases the service life of the existing pavement. The CIR layer is typically overlaid by the hot mix asphalt (HMA) to protect it from water ingress and traffic load and obtain the required pavement structure and texture. Most public agencies have different curing requirements based on the number of curing days or the maximum moisture contents for the CIR before placing the overlay. The main objective of this study is to develop a moisture loss index that the public agency can use to monitor the moisture content of CIR layers in preparation for a timely placement of the wearing surface. First, the moisture contents were measured in the field using a portable time domain reflectometry (TDR) device. Second, the weather information in terms of rain fall, air temperature, humidity and wind speed was collected from the same location. Finally, a moisture loss index was developed as a function of initial moisture content, air temperature, humidity and wind speed. The developed moisture loss index based on the field measurements would help the public agency to determine an optimum timing of an overlay placement without continually measuring moisture conditions in the field.

Evaluation of Rutting Resistance and Moisture Sensitivity of Warm-Mix Asphalt Mixtures Using the Model Mobile Loading Simulator(MMLS3) (소형 포장 가속시험기를 이용한 중온 아스팔트 혼합물의 소성변형저항성 및 수분민감도 평가)

  • Lee, Jae-Jun;Kim, Yong-Joo;Yang, Sung-Lin;Kwon, Soo-Ahn;Hwang, Sung-Do
    • International Journal of Highway Engineering
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    • v.13 no.2
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    • pp.41-48
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    • 2011
  • Warm-mix asphalt(WMA) technology has been developed to allow asphalt mixtures to be produced and compacted at a significantly lower temperature. The WMA technology was identified as one of means to lower emissions for $CO_2$ and has been spread so quickly in the world. Recently, two innovative WMA additives has been developed to reduce mixing and paving temperatures applied in asphalt paving process in Korea. Since the first public demonstration project in 2008, many WMA projects have successfully been constructed in national highways. In 2010, the WMA field trial was conducted on new national highway construction under Dae-Jeon Regional Construction Management Administration. The two different WMA loose mixtures(WMA and WMA-P) and a HMA mixture were collected at the asphalt plant to evaluate their mechanical performance in the laboratory. The Third-scale Model Mobile Loading Simulator(MMLS3) was adopted to evaluate rutting resistance and moisture damage under different traffic and environmental conditions. In this study, plant-produced WMA mixtures using two WMA additives along with the conventional hot mix asphalt(HMA) mixtures were evaluated with respect to their rutting resistance and moisture susceptibility using MMLS3. Based on the limited laboratory test results, plant-produced WMA mixtures are superior to HMA mixtures in rutting resistance and the moisture susceptibility. The WMA additive was effective for producing and compacting the mixture at $30^{\circ}C$ lower than the temperature for the HMA mixture.

Construction Methods of Switching Network for a Small and a Large Capacity AMT Switching System (소용량 및 대용량의 ATM시스템에 적합한 스위칭 망의 구성 방안)

  • Yang, Chung-Ryeol;Kim, Jin-Tae
    • The Transactions of the Korea Information Processing Society
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    • v.3 no.4
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    • pp.947-960
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    • 1996
  • The primary goal for developing high performance ATM switching systems is to minimized the probability of cell loss, cell delay and deterioration of throughput. ATM switching element that is the most suitable for this purpose is the shared buffer memory switch executed by common random access memory and control logic. Since it is difficult to manufacture VLIS(Very Large Scale Integrated circuit) as the number of input ports increased, the used of switching module method the realizes 32$\times$32, 150 Mb/s switch utilizing 8$\times$8, 600Mb/s os 16$\times$16, 150Mb/s unit switch is latest ATM switching technology for small and large scale. In this paper, buffer capacity satisfying total-memory-reduction effect by buffer sharing in a shared buffer memory switch are analytically evalu ated and simulated by computer with cell loss level at traffic conditions, and also features of switching network utilizing the switching module methods in small and large-capacity ATM switching system is analized. Based on this results, the structure in outline of 32$\times$32(4.9Gb/s throughput), 150Mb/s switches under research in many countries is proposed, and eventually, switching-network structure for ATM switching system of small and large and capacity satisfying with above primary goals is suggested.

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Extended Service Filtering Technique for Overload Control of Televoting Service Required for the Specialized Resources of Intelligent Peripheral (지능형 정보제공 시스템의 특수 지원을 이용하여 제공되는 전화투표 서비스의 과부하 제어를 위한 확장된 서비스 필터링 기법)

  • Jeong, Gwang-Je
    • The Transactions of the Korea Information Processing Society
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    • v.3 no.7
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    • pp.1727-1738
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    • 1996
  • This paper proposes a extended service filtering technique to solve overload control problems inService Con-trol Poin(SCP) due to Televoting (VOT) services with heavy traffic characteristics. Also, this paper compares this new technique with existing IN overload control lechniques, and calculate steady state call blocking probabilities in In under overload conditions. The proposed technique considers SCP overload and IN CS-1services such as VOT service that need to use the specialized resources of IP. This technique uses first an activating step which SCP sends service filtering request to SSP and IP for the start of service filtering. Then, in the filtering step SSP sendas filtering results to SCP periodically or each N-calls.Also,when filtering time-out timer expired or call counter value exceeded maximum number of calls,SSP stops service filtering,and sends ser-vice filteing response to SCP in the deactivating step. The application of this techique to VOT service defined in IN CS-1 service is investigated and analyzed by using an analytical VOT service model.In order to apply this technique to VOT service, this paper also discusses VOT service and the corresponding N architecture including Service Switching Point(SSP),SCP and IP. Then this paper also constructs an analytical VOT service model,and calculates SCP and SSP/IP(circuit)call blocking probablities.With the application of this new technique,this paper shows good performance enhancements in SCP call blocking probability.

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Road Facility DB Improvement Using DGPS Camera (DGPS 카메라를 활용한 도로시설물 DB 개선)

  • Lee, Je-Jung;Lee, Jong-Sin;Kim, Min-Gyu
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.2
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    • pp.905-910
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    • 2013
  • Road facility has the high possibility of being damaged or destroyed due to continuous pass of the vehicles, overloaded vehicles, traffic accidents and so on and stormwater manhole, sewerage manhole that are installed on the road may cause the functional degradation in case of periodic pavement of the road. So management through establishing DB of road facility and efficient updating plan are required. Thus, this study used DGPS camera for efficient establishment and improvement of road facility DB. Applicability of DGPS camera could be suggested by satisfying the allowable accuracy required for establishing DB of road facility through the comparative analysis with the result of establishment of existing road facility DB and the process of DB establishment by existing total solution could be improved through process analysis. And the existing DB of road facility was improved so that the present conditions of surrounding topography and road facility can be grasped by developing the module that can add the images of road facility to digital map and Google Earth-based KML Builder. It is expected that road facility service that provides various information can be available if the spatial data of each local self-governing body and study of automation that utilizes DGPS camera images are accomplished hereafter.

An Empirical Study on the Improvment of VTS in Korea (우리나라 선박교통제제도의 개선방안에 관한 실증연구 - 포항항을 중심으로 -)

  • 임을빈;문성혁
    • Journal of the Korean Institute of Navigation
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    • v.21 no.2
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    • pp.47-58
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    • 1997
  • The purpose of this study is to find out the impacts of VTS on the marine safety and users' opinion on the VTS which have been being operated in the port of Pohang for the last 3 years and is to suggest a guideline to the successful operation of VTS in the future. This study is based upon the questionnaire survey and the respondents include 236 masters/mates of merchant vessels who have visited the port of Pohang and 6 pilots who have been working in the port. From the questionnaire results, this study notes the following conclusions related to the VTS operations. (1) A few of the respondents (mainly foreigners) do not understand the entering procedure of the port and the fundamental concept of VTS. Accordingly, the more active VTS services have to be provided for the mariners. (2) It was found that themost dangerous factors in tehvicinity of the port were the floating materials, fishing nets, andillegal fishing activities inthe fairway. Therefore, the proper surveillance, stricter enforcement of Acts and the instructive education for the fishermen are required to avoid the risks. (3) A majority of the respondents agreed the VTS has contributed to the safety of vessel traffic, and they pointed out ' the assiatances in reduced visibililty conditions' is the most important task of VTS. The amount of 75.6% of the respondents answered that they have experienced the assistance from VTS more than 1 time since the system was established in the port of Pohang . Also 44.2% of the respondents considered they were able to avoid marine casualties such as collision, ramming or agrounding with the VTS assistances. (4) 49.2% of the respondents preferred the passive information services , while, 38.8% of them preferred the positive control advices in the case of encountering any potential risks. VTS iperators have to consider seriously when they provide the positive control advices of ship's course and speed. (5) A majority of the respondents confirmed that the prot and its approaches is suitable for the VTS coverge . To extend the service areas of the VTS and to improve radar detecting ability, the use of radar transponders are seen as the ideal method. (6) A minority of the respondents pointed out 'the improper orders or recommendatinos caused by the poor decision making' firstly, ' the language problem(sea-speaking in English)' secondly, as the deficiency of personal qualification. It seems, therefore, theat the personal efforts of the operators and systematic training programmes for them are necessary to solve the problems.

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Network Adaptive Quality of Service Method in Client/Server-based Streaming Systems (클라이언트/서버 기반 스트리밍 시스템에서의 네트워크 적응형 QoS 기법)

  • Zhung, Yon-il;Lee, Jung-chan;Lee, Sung-young
    • The KIPS Transactions:PartA
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    • v.10A no.6
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    • pp.691-700
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    • 2003
  • Due to the fast development of wire&wireless internet and computer hardware, more and more internet services are being developed, such as Internet broadcast, VoD (Video On Demand), etc. So QoS (Qualify of Service) is essentially needed to guarantee the quality of these services. Traditional Internet is Best-Effort service in which all packets are transported in FIFO (First In First Out) style. However, FIFO is not suitable to guarantee the quality of some services, so more research in QoS router and QoS protocol are needed. Researched QoS router and protocol are high cost and inefficient because the existing infra is not used. To solve this problem, a new QoS control method, named Network Adaptive QoS, is introduced and applied to client/server-based streaming systems. Based on network bandwidth monitoring mechanism, network adaptive QoS control method can be used in wire&wireless networks to support QoS in real-time streaming system. In order to reduce application cost, the existing streaming service is used in NAQoS. A new module is integrated into the existing server and client. So the router and network line are not changed. By simulation in heavy traffic network conditions, we proved that stream cannot be seamless without network adaptive QoS method.