• Title/Summary/Keyword: Traffic demand

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A Integrated Model of Land/Transportation System

  • 이상용
    • Proceedings of the KOR-KST Conference
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    • 1995.12a
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    • pp.45-73
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    • 1995
  • The current paper presents a system dynamics model which can generate the land use anq transportation system performance simultaneously is proposed. The model system consists of 7 submodels (population, migration of population, household, job growth-employment-land availability, housing development, travel demand, and traffic congestion level), and each of them is designed based on the causality functions and feedback loop structure between a large number of physical, socio-economic, and policy variables. The important advantages of the system dynamics model are as follows. First, the model can address the complex interactions between land use and transportation system performance dynamically. Therefore, it can be an effective tool for evaluating the time-by-time effect of a policy over time horizons. Secondly, the system dynamics model is not relied on the assumption of equilibrium state of urban systems as in conventional models since it determines the state of model components directly through dynamic system simulation. Thirdly, the system dynamics model is very flexible in reflecting new features, such as a policy, a new phenomenon which has not existed in the past, a special event, or a useful concept from other methodology, since it consists of a lots of separated equations. In Chapter I, II, and III, overall approach and structure of the model system are discussed with causal-loop diagrams and major equations. In Chapter V _, the performance of the developed model is applied to the analysis of the impact of highway capacity expansion on land use for the area of Montgomery County, MD. The year-by-year impacts of highway capacity expansion on congestion level and land use are analyzed with some possible scenarios for the highway capacity expansion. This is a first comprehensive attempt to use dynamic system simulation modeling in simultaneous treatment of land use and transportation system interactions. The model structure is not very elaborate mainly due to the problem of the availability of behavioral data, but the model performance results indicate that the proposed approach can be a promising one in dealing comprehensively with complicated urban land use/transportation system.

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The Hospital Life of the Patient with Femoral Neck Fracture (대퇴경부 골절 환자의 입원 생활)

  • Kim, Kyung-Ja;Chi, Sung-Ai
    • Journal of Korean Academy of Nursing Administration
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    • v.2 no.1
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    • pp.35-56
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    • 1996
  • Nowerdays, the increase of traffic accidents and old age population make the Femoral Neck Fracture(FNF) patients increase. By the improvement of education and standard of living the patients demand better medical service than before. This study is designed to give practical help for the FNF patients by observing their hospital life and establish practical nursing strategies for the FNF patients. For these purposes the Ethnographic Participant Observation was adopted. By this study is focused on the hospital life patient's view. For this end, the field study adopted orthopedic ward in the C University Hospital with 400 beds in Seoul. The object patients of the study were twelve patients. The patients experienced five stages : Embarrassment, Conflict, Stability, Independent, and Extension Stage. The findings and prepared nursing strategies are stated as follows. First, in the Embarrassment Stage they suffered embarrassment, anxiety, pain, they could not do ordinary things. The patients who accidental fractures had anxiety from unfamiliar tests and from hospitalization itself. They lamented that they could not ordinary things, and do nothing but obeying the hospital, and endure the pain. They recognized the changed environment and resigned themselves to life in the ward. In this stage, full openness by the nurses is needed. Second, the attribute of the Conflict Stage were conflict, fear, curiosity, belief, reflection. When they sign the consentment form, they experience conflicts about the possibility of complication, fear of recovery from anesthesia, curiosity about the operation procedure, post - operation state, reflection on their past life, and promise to care for their family members after discharge and keep their religious life faithfully. And they accepted the operation depending on God, believing in modern medicine, and the surgeon. Asking for their changed informations, they expected positive results from the operation. In this stage, an empathic attitude by the nurses is needed. Third, the attribute of the Stability Stage were relief, gratitude, difficulty with excretion, and pain. When they awoke from anesthesia, they felt relief because of a the end of the operation, but they experienced extreme pain, difficulty of excretion in bed. They accepted the changed environment and expected recovery. In this stage, support by the nurses is needed. Fourth, the attributes of the Independence Stage were freedom, exercise, nurturing, anxiety, and discomfort. When they ambulated and exercised, they experienced freedom. They showed exhibited weakness of the digestive organs and discomfort hospital's space, structure, and facilities, the delay of medical certificate issue the lack of prompt response by the medical agents. They ate nurturious food and felt anxiety on the end of hospital life and returning to their ordinary life. They showed the independence of overcoming their environment by increasing exercise and expected their discharges. In this stage, respect by the nurses is needed for the patients to, overcome their environment and prepare for their independence. Fifth, the attributes of the Extension Stage were pessimism, isolation, dissatisfaction, and pain. Accompanied injury and old age made their ward life extend to over seven weeks. They exhibited weariness, melancholy, skeptisis, general pessimistic feeling, and desperation caused by their isolated life. They experienced the digestive discomfort caused by the prolonged medication and psycological pain caused by long-time hospitalization. As a, result, their dissatisfaction on the human, physical, and systematic environments had been increased. They acquired critical power and sought for something to do spending their time. They expected vaguely about the returning of their ordinary life. In this stage, counseling is needed by the nurse to overcome positively their psychological, social, and physical problems. The process of the FNF patient's ward life starts from the dependent state, when they are hospitalized, and gradually progresses to self-fulfillment in order to keep independent life. As a result, the FNF patients showed "Response in Challenge" or "Adaptation in Conflict" through their experiences of social, physical, and psychological difficulties.

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The Method of Participatory Government to Introduce the System of Autonomous Police (참여정부의 자치경찰제 도입방안)

  • Jung, Jin-Hwan
    • Korean Security Journal
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    • no.10
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    • pp.355-385
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    • 2005
  • As the system of autonomous police that has been debated for long time is fixed to be introduced by the program of participatory government, this treatise intends to analyze main contents and review controversial items in order to present supplementary measures. The program of participatory government to introduce autonomous police in Korea focuses on converting the autonomous police of Korea from centralized police administration in order to provide 'customized security service' that is appropriate to the regional environment. Thus, if relevant city, county or district considers that it is required to introduce the system autonomous police, the assembly may enforce the decision by enacting ordinance. For enforcement, organization in the unit of section will be established in the line of mayor, county headman and district office. The main role will be security service that is closely related to the life of inhabitants such as crime prevention, patrol, traffic crackdown, etc. as well as public health, sanitation and environmental control which are being performed by autonomous organization at present. However some expected controversial items may be summarized in the following 3 points on the premise of accepting the program of government. First, the point at issue related to the basic function of police. The basic function of police is generally understood as order keeping function such as anterior and preventive job and law enforcing function such as posterior and suppressing job. By the way, the program of government does not endow the autonomous police with investigation right for general crime, thereby raising the controversy that our autonomous police is nothing but the assistant of police. Furthermore, the present national police also expresses its dissatisfaction to the transfer of authority. Second, the issue of balance of security service between self-governing bodies may be raised. The security environment is different between self-governing bodies and thus demand of security is different. Therefore, the security service of autonomous police will reveal difference in qualitative aspect for each self-governing body. Moreover, it can be easily anticipated that the quality of security service may be different as per the financial independence degree. Third, the point at issue anticipated with the operation funded by the budget of self-governing body. As autonomous police is operated by the budget of self-governing body, the following problems may be raised; (1) since police administration is subordinated to general administration, the concentration may be weakened (2) the cooperation between policy agencies may be impeded (3) owing to the difficult in possessing spare police, the mobility of police may be somewhat reduced.

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Performance Evaluation of a Dynamic Bandwidth Allocation Algorithm with providing the Fairness among Terminals for Ethernet PON Systems (단말에 대한 공정성을 고려한 이더넷 PON 시스템의 동적대역할당방법의 성능분석)

  • Park Ji-won;Yoon Chong-ho;Song Jae-yeon;Lim Se-youn;Kim Jin-hee
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.11B
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    • pp.980-990
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    • 2004
  • In this paper, we propose the dynamic bandwidth allocation algorithm for the IEEE802.3ah Ethernet Passive Optical Network(EPON) system to provide the fairness among terminals, and evaluate the delay-throughput performance by simulation. For the conventional EPON systems, an Optical Line Termination (OLT) schedules the upstream bandwidth for each Optical Network Unit (ONU), based on its buffer state. This scheme can provide a fair bandwidth allocation for each ONU. However, it has a critical problem that it does not guarantee the fair bandwidth among terminals which are connected to ONUs. For an example, we assume that the traffic from a greedy terminal increases at a time. Then, the buffer state of its ONU is instantly reported to the OLT, and finally the OW can get more bandwidth. As a result, the less bandwidth is allocated to the other ONUs, and thus the transfer delay of terminals connected to the ONUs gets inevitably increased. Noting that this unfairness problem exists in the conventional EPON systems, we propose a fair bandwidth allocation scheme by OLT with considering the buffer state of ONU as welt as the number of terminals connected it. For the performance evaluation, we develop the EPON simulation model with SIMULA simulation language. From the result of the throughput-delay performance and the dynamics of buffer state along time for each terminal and ONU, respectively, one can see that the proposed scheme can provide the fairness among not ONUs but terminals. Finally, it is worthwhile to note that the proposed scheme for the public EPON systems might be an attractive solution for providing the fairness among subscriber terminals.

A Comparison of Single and Multi-matrix Models for Bird Strike Risk Assessment (단일 및 다중 매트릭스 모델의 비교를 통한 항공기-조류 충돌 위험성 평가 모델 분석)

  • Hong, Mi-Jin;Kim, Myun-Sik;Moon, Young-Min;Choi, Jin-Hwan;Lee, Who-Seung;Yoo, Jeong-Chil
    • Korean Journal of Environment and Ecology
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    • v.33 no.6
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    • pp.624-635
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    • 2019
  • Bird strike accidents, a collision between aircraft and birds, have been increasing annually due to an increasing number of aircraft operating each year to meet heavier demand for air traffic. As such, many airports have conducted studies to assess and manage bird strike risks effectively by identifying and ranking bird species that can damage aircraft based on the bird strike records. This study was intended to investigate the bird species that were likely to threaten aircraft and compare and discuss the risk of each species estimated by the single-matrix and multi-matrix risk assessment models based on the Integrated Flight Information Service (IFIS) data collected in Gimpo, Gimhae and Jeju Airports in South Korea from 2005 to 2013. We found that there was a difference in the assessment results between the two models. The single-matrix model estimated 2 species and 6 taxa in Gimpo and Gimhae Airports and 2 species and 5 taxa in Jeju Airport to have the risk score above "high," whereas the multi-matrix model estimated 3 species and 5 taxa in Gimpo Airport, 4 species and 5 taxa in Gimhae Airport, and 2 species and 3 taxa in Jeju Airport to have the risk score above "very high." Although both models estimated the similar high-risk species in Gimpo and Gimhae Airports, there was a significant difference in Jeju Airport. Gimpo and Gimhae Airports are near the estuary of a river, which is an excellent habitat for large and heavy waterbirds. On the other hand, Jeju Airport is near the coast and the city center, and small and light bird species are mostly observed. Since collisions with such species have little effect on aircraft fuselage, the impact of common variables between the two models was small, and the additional variables caused a significant difference between the estimation by the two models.

The International Civil Aviation Organization and Recent Developments of Air Law in a Changing Environment (변환기(變換期)에 있어서의 국제민간항공기구(國際民間航空機構)(ICAD)와 항공법(航空法) 발전(發展)의 최근(最近) 동향(動向))

  • Choi, Wan-Sik
    • The Korean Journal of Air & Space Law and Policy
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    • v.4
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    • pp.7-35
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    • 1992
  • The expansion of air transport on a global scale with ever increasing traffic densities has brought about problems that must be solved through new multilateral mechanisms. Looking to the immediate future, air transport will require new forms of international cooperation in technical and economic areas. Air transport by its very nature should have been a counterforce to nationalism. Yet, the regulatory system in civil aviation is still as firmly rooted in the principle of national sovereignty as when it was first proclaimed at t-11e Paris Convention of 1919 and reaffirmed in the Chicago Convention. Sovereignty over the airspace has remained the cornerstone of relations between states in all respects of air transport. The importance of sovereignty over air space embodied in article 1 of the Chicago Conrenton also is responsible for restricting the authority of ICAO as an intergovernmental regulatory agency. The Orgenization, for all its extensive efforts, has only limited authority. ICAO sets standards but cannot enforce them; it devises solutions but cannot impose them. To implement its rules ICAO most rely not so much on legal requirements as on the goodwill of states. It has been forty-eight years since international community set the foundations of the international system in civil aviation action. Profound political, economic and technological changes have taken place in air transport. The Chicago Convention is living proof that staes can work together to make air transport a safe mode of travel. The law governing international civil auiation is principally based on international treaties and on other regulation agreed to by governments, for the most part through the mechanism of ICAO. The role of ICAO international standards and recommended practices and procedures dealing with a broad range of technical matters could hardly be overestimated. The organization's ability to develop these standards and procedures, to adapt them continuously to the rapid sate of change and development of air transport, should be particularly stressed. The role of ICAO in the area of the development of multilateral conventions on international air law has been successful but to a certain degree. From the modest starting-point of the Tokyo Convention, we have seen more adequate international instruments prepared within the scope of ICAO activities, adopted: the Hague Convention of 1970 for the suppression of Unlawful Seizure of Aircraft and the Montreal Convention of 1971 for the Suppression of Unlawful Acts against the Safety of Civil Aviation. The work of ICAO in the new domain of international law conventions concerning what has been loosely termed above as the criminal problems connected with international air transport, in particular the problem of armed aggression against aircraft, should be positively appreciated. But ICAO records in the domain of developing a uniform legal system of international carriage by air are rather disappointing. The problem of maintaining and developing the uniformity of this regulation exceeds the scope of interest and competence of governmental transport agencies. The expectations of mankind linked to it are too great to give up trying to restore the uniform legal system of international air carriage that would create proper conditions for its further growth. It appears that ICAO has, at present, a good opportunity for doing this. The hasty preparation of ICAO draft conventions should be definitely excluded. Every Preliminary draft convention ought to be sent to Governments of all member-States for consideration, So that they could in form ICAO in due time of their observation. The problom of harmonizing a uniform law of international air carriage with that of other branches of international transport should demand more and more of its attention. ICAO cooperation with other international arganization, especially these working in the field of international transport, should be strengthened. ICAO is supposed to act as a link and a mediator among, at times the conflicting interests of member States, serving the happiness and peace of all of the world. The transformation of the contemporary world of developing international relations, stimulated by steadily growing international cooperation in its various dimensions, political, economic, scientific, technological, social and cultural, continuously confronts ICAO with new task.

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Current Situation and Cooperation on the Metropolitan Airport between Korea and Japan (한국 및 일본의 수도권 공항의 현황과 협력)

  • Kim, Doo-Hwan
    • The Korean Journal of Air & Space Law and Policy
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    • no.spc
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    • pp.137-163
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    • 2007
  • The air market in Asia has already entered upon the age of limitless competition. It means a very important moment in Asia air market. Each Asian country thus has put a lot of effort into a development plan and support to their hub airport. In order to achieve such a plan, first of all we should build closer cooperation system between the two countries Japan and Korea. The Korea and Japan are very fast growing in the northeast countries within the global air transport market. Air passenger and cargo traffic volumes between Korea and Japan have increased dramatically, since the 1990s. In response to such a trend, both countries have opened new airports and expanded existing facilities in the hopes of laying claims to the main international hub airport in Asia. Apart from the trend, air transportation between Korea and Japan's metropolitan areas is the only transportation in substance, even if they are located very closely in geographical position. The air transportation between the two countries shows that it is necessary to get fast and more convenient because of the economic and cultural interchange and exchange concentrated on the metropolitan areas, and that will promote the economic growth of Korea and Japan. However, within the air transportation industry field, there have no sufficient seats/slots to supply the air demand from the capital cities of each country, as well as no counterplan for some problems regarding capacityand sustain ability of metropolitan airports. Thus, it is necessary for us to consider in all aspects and solve them to improve air transportation between Korea and Japan. This paper is to try to demonstrate this matter and from all angles, that is, in legal and political aspects, facilities and given environmental conditions and cooperation between Korea and Japan. I think that it is indeed a great necessary and convenient for many Korean and Japanese tourists to conclude a new 'Open Sky Agreement' between Japan and Korea in order to the prepare the increase of the shuttle flight between Haneda-Gimpo and opening of air route newly for shuttle flight between Haneda and Cheongju as well as opening of air route for shuttle flight between Haneda-Shanghai Hongqiao International Airport and Beijing International Airport for the 2008 Beijing Olympic Games. Furthermore it is a great desirable thing for us to conclude a new 'Open Sky Agreement' in cooperation reciprocally among the Japan, China and Korea for opening the new air route by the shuttle flight.

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PST Member Behavior Analysis Based on Three-Dimensional Finite Element Analysis According to Load Combination and Thickness of Grouting Layer (하중조합과 충전층 두께에 따른 3차원 유한요소 해석에 의한 PST 부재의 거동 분석)

  • Seo, Hyun-Su;Kim, Jin-Sup;Kwon, Min-Ho
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.22 no.6
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    • pp.53-62
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    • 2018
  • Follofwing the accelerating speed-up of trains and rising demand for large-volume transfer capacity, not only in Korea, but also around the world, track structures for trains have been improving consistently. Precast concrete slab track (PST), a concrete structure track, was developed as a system that can fulfil new safety and economic requirements for railroad traffic. The purpose of this study is to provide the information required for the development and design of the system in the future, by analyzing the behavior of each structural member of the PST system. The stress distribution result for different combinations of appropriate loads according to the KRL-2012 train load and KRC code was analyzed by conducting a three-dimensional finite element analysis, while the result for different thicknesses of the grouting layer is also presented. Among the structural members, the largest stress took place on the grouting layer. The stress changed sensitively following the thickness and the combination of loads. When compared with a case of applying only a vertical KRL-2012 load, the stress increased by 3.3 times and 14.1 times on a concrete panel and HSB, respectively, from the starting load and temperature load. When the thickness of the grouting layer increased from 20 mm to 80 mm, the stress generated on the concrete panel decreased by 4%, while the stress increased by 24% on the grouting layer. As for the cracking condition, tension cracking was caused locally on the grouting layer. Such a result indicates that more attention should be paid to the flexure and tension behavior from horizontal loads rather than from vertical loads when developing PST systems. In addition, the safety of each structural member must be ensured by maintaining the thickness of the grouting layer at 40 mm or more.

Development of the forecasting model for import volume by item of major countries based on economic, industrial structural and cultural factors: Focusing on the cultural factors of Korea (경제적, 산업구조적, 문화적 요인을 기반으로 한 주요 국가의 한국 품목별 수입액 예측 모형 개발: 한국의, 한국에 대한 문화적 요인을 중심으로)

  • Jun, Seung-pyo;Seo, Bong-Goon;Park, Do-Hyung
    • Journal of Intelligence and Information Systems
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    • v.27 no.4
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    • pp.23-48
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    • 2021
  • The Korean economy has achieved continuous economic growth for the past several decades thanks to the government's export strategy policy. This increase in exports is playing a leading role in driving Korea's economic growth by improving economic efficiency, creating jobs, and promoting technology development. Traditionally, the main factors affecting Korea's exports can be found from two perspectives: economic factors and industrial structural factors. First, economic factors are related to exchange rates and global economic fluctuations. The impact of the exchange rate on Korea's exports depends on the exchange rate level and exchange rate volatility. Global economic fluctuations affect global import demand, which is an absolute factor influencing Korea's exports. Second, industrial structural factors are unique characteristics that occur depending on industries or products, such as slow international division of labor, increased domestic substitution of certain imported goods by China, and changes in overseas production patterns of major export industries. Looking at the most recent studies related to global exchanges, several literatures show the importance of cultural aspects as well as economic and industrial structural factors. Therefore, this study attempted to develop a forecasting model by considering cultural factors along with economic and industrial structural factors in calculating the import volume of each country from Korea. In particular, this study approaches the influence of cultural factors on imports of Korean products from the perspective of PUSH-PULL framework. The PUSH dimension is a perspective that Korea develops and actively promotes its own brand and can be defined as the degree of interest in each country for Korean brands represented by K-POP, K-FOOD, and K-CULTURE. In addition, the PULL dimension is a perspective centered on the cultural and psychological characteristics of the people of each country. This can be defined as how much they are inclined to accept Korean Flow as each country's cultural code represented by the country's governance system, masculinity, risk avoidance, and short-term/long-term orientation. The unique feature of this study is that the proposed final prediction model can be selected based on Design Principles. The design principles we presented are as follows. 1) A model was developed to reflect interest in Korea and cultural characteristics through newly added data sources. 2) It was designed in a practical and convenient way so that the forecast value can be immediately recalled by inputting changes in economic factors, item code and country code. 3) In order to derive theoretically meaningful results, an algorithm was selected that can interpret the relationship between the input and the target variable. This study can suggest meaningful implications from the technical, economic and policy aspects, and is expected to make a meaningful contribution to the export support strategies of small and medium-sized enterprises by using the import forecasting model.