• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.1
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• pp.45-57
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• 2005

In this paper, we extend the performance of bidirectional TCP connection over end-to-end network that uses transfer rate-based flow and congestion control. The sharing of a common buffer by TCP packets and acknowledgement has been known to result in an effect called ack compression, where acks of a connection arrive at the source bunched together, resulting in unfairness and degraded throughput. The degradation in throughput due to bidirectional traffic can be significant. Even in the simple case of symmetrical connections with adequate window size, the connection efficiency is improved about 20% for three levels of background traffic 2.5Mbps, 5.0Mbps and 7.5Mbps. Otherwise, the throughput of jitter is reduced about 50% because round trip delay time is smaller between source node and destination node. Also, we show that throughput curve is improved with connection rate algorithm which is proposed for TCP congetion avoidance as a function of aggressiveness threshold for three levels of background traffic 2.5Mbps, 5Mbps and 7.5Mbps. By analyzing the periodic bursty behavior of the source IP queue, we derive estimated for the maximum queue size and arrive at a simple predictor for the degraded throughput, applicable for relatively general situations.

• The Journal of the Korea institute of electronic communication sciences
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• v.1 no.2
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• pp.102-109
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• 2006

In this paper, we improve the performance of bidirectional TCP connection over end-to-end network that uses transfer rate-based flow and congestion control. The sharing of a common buffer by TCP packets and acknowledgement has been known to result in an effect called ack compression, where acks of a connection arrive at the source bunched together, resulting in unfairness and degraded throughput. The degradation in throughput due to bidirectional traffic can be significant. For example, even in the simple case of symmetrical connections with adequate window size, the connection efficiency is improved about 20% for three levels of background traffic 2.5Mbps, 5.0Mbps and 7.5Mbps. Otherwise, the throughput of jitter is reduced about 50% because round trip delay time is smaller between source node and destination node. Also, we show that throughput curve is improved with connection rate algorithm which is proposed for TCP congestion avoidance as a function of aggressiveness threshold for three levels of background traffic 2.5Mbps, 5Mbps and 7.5Mbps.

• Journal of Korean Society of Transportation
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• v.23 no.7 s.85
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• pp.63-74
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• 2005

When we introduce the BRT systems, it is very important to decide the operating factors, such as bus-stop locations or headway. If the factors are inappropriate, unessential expenses for the operator and users of the bus line may be caused, and it leads increase of social total cost. So, it is necessary that we consider users' origin and destination of each bus line when we set location of bus-stops and the optimal headway. Meanwhile, Smart Card System was introduced of fare collection for the Public Transportation Reform in Seoul last year. This new card system makes it possible to store up the information about bus operating and passenger's trip link. With these substantial information. we can estimate bus-stop-based O-D table. So, in this thesis, it was studied a systematic methodology to find the optimal location and headway for skip-stop bus system (as a type of first step for BRT). The proposed methodology in this thesis is expected to be useful to effect analysis or setting operating factors for skip-stop bus system in each bus line.

• Proceedings of the Korean Information Science Society Conference
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• 2010.06a
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• pp.38-39
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• 2010

수도권 대중교통 이용자는 2004년 서울시의 대중교통 체계 개편에 따라 교통 카드를 사용하여 버스와 지하철을 이용하게 되었다. 교통 카드를 사용하는 각 승객의 승차와 하차에 관한 데이터가 하나의 트랜잭션으로 구성되고, 하루 천만 건 이상의 트랜잭션들로 구성된 대용량 교통카드 트랜잭션 데이터베이스가 만들어지고 있다. 대중교통을 이용하는 승객들의 승차와 하차에 관한 여러 정보를 담고 있는 교통카드 트랜잭션 데이터베이스에서 유용한 패턴이나 정보를 탐사해내는 연구가 계속 진행되고 있다. 이런 연구 결과는 수도권 대중교통 정책을 입안하는데 중요한 기초 자료가 되고 수도권 승객들에게 대중교통을 보다 잘 이용할 수 있는 정보로 제공된다. 교통카드 이용률은 2006년 79.5%, 2007년 80.3%, 2008년 81.6%로 점차적으로 증가하고 있다. 대용량의 교통카드 트랜잭션 데이터베이스에 대한 연구를 살펴보면 하루 동안의 교통카드 트랜잭션 데이터베이스에서 순차 패턴을 탐사하는 알고리즘을 연구하였고[1], 승객들의 통행 패턴에 대한 분석연구를 확장하여 일 년에 하루씩 2004년에서 2006년까지 3일간의 교통카드 트랜잭션 데이터베이스로부터 승객 시퀀스의 평균 정류장 개수와 환승 횟수 등을 연도별로 비교하였다[2]. 수도권 지하철 시스템의 특성에 관한 연구로는 네트워크 구조 분석이 있었고[3], 승객의 기종점 통행 행렬(Origin-Destination trip matrix)에 의한 승객 흐름의 분포가 멱함수 법칙(power law)임을 보여주는 연구가 있었고[4], 지하철 교통망에서 모든 링크상의 승객들의 흐름을 찾아내는 연구가 있었다[5]. 본 논문에서는 교통카드 트랜잭션 데이터베이스에서 지하철 승객들의 통근 패턴을 탐사해내는 방법을 연구하였다. 수도권 지하철 네트워크에 대한 정보를 입력하고 하루치의 교통카드 트랜잭션 데이터베이스에 연구된 방법을 적용하여 8가지 통근 패턴들을 탐사해내고 분석하였다. 탐사된 패턴들 중에서 많은 승객들이 지지하는 출퇴근 패턴에 대해서는 시간대별로 승객수를 그래프로 보여주었다.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.2166-2178
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• 2010

The Korea Transportation Database (KTDB) is used to obtain data on the origin and destination (OD) of inter-city travel, which are currently used in railroad planning when estimating traffic demand. The KTDB employs the trip assignment method, whereby the total traffic volume researched for inter-city travel in Korea is divided into road, rail and air traffic, etc. However, as regards rail travel, the railroad stations are not identical to the existing zones or the connector has not been established because there are several stations in one zone as such, certain problems with the applicable methods have been identified. Therefore, estimates of the volume of railroad traffic using the KTDB display low reliability compared to other modes of transportation. In this study, these problems are reviewed and analyzed, and use of the aggregate model method to estimate the direct demand for rail travel is proposed in order to improve the reliability of estimation. In addition, a method of minimizing error in traffic demand estimation for the railroad field is proposed via an analysis of the relationship between the aggregate model and various social-economic indicators including population, distances, numbers of industrial employees, numbers of automobiles, and the extension of roads between cities.

• Journal of the Korean Institute of Landscape Architecture
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• v.40 no.6
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• pp.98-111
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• 2012

This study found the possibility of using cemeteries within the locality as field trip destination. A comparison between Korea and the United States of America's active progress has derived the difference and the implications. Therefore, this article found that the cemetery has sufficient resources based on experience-learning place within the community. Therefore, when the active educational program was developed; it gained more abundant resources for education, as well as provided more different educational opportunities for the students than now. As the result of comparison, the reason why the educational program is actively progressing in the American cemeteries is that a beautiful and fresh environment has been built up such as a park or garden in a cemetery and has been preserved as a healthy forest ecosystem. Furthermore, it is because they actively used the cemetery within a community as the subject. If our cemetery can be renovated and the funeral culture can be changed to break down the image of an avoidable unpleasant facility, it would play a role as a field for learning experience.

• Journal of Korean Society of Transportation
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• v.25 no.4
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• pp.21-32
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• 2007

The households to be surveyed are usually huge number at the level of a city or metropolitan survey, not to mention a nationwide travel survey. Therefore, household travel surveys to figure out true origin-destination (O/D) trip patterns (population O/D) are conducted through a sampling method rather than by surveying all of the population in the system. Therefore, the population O/D pattern can only be estimated by expanding the sampled O/D patterns to the population. It is very difficult to avoid the errors involved in the process of sampling, surveying and expanding O/D data. In order to minimize such errors while estimating the true O/D patterns of the population, the validation and adjustment process should employed by doing a comparison between the expanded sample O/D data and observed link traffic volumes. This study suggests a method of validation and adjustment of the expanded sample O/D data by comparing observed link volumes at several screenlines. The study also suggests a practical technique to modify O/D pairs which are excluded in the screenline validation process by comparing observed traffic volume with the results of traffic assignment analysis. An empirical study was also conducted as an example applying the suggested methods of validation and adjustment with Korea's nationwide O/D data and highway network.

• Spatial Information Research
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• v.19 no.6
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• pp.75-86
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• 2011

This paper proposes a modified way to delimit the boundary of Busan metropolitan area and compares the empirical analysis with the existing metropolitan area boundary. More specifically, the present state of the metropolitan transportation network is reflected by service area analysis in our study area. The analysis of the linkage between the central city and its fringes considers various travel behaviors as well as commuting to work and school, based on origin-destination trip information. In addition, more diverse indices are applied to the analysis of urban characteristics, and the land cover map is used as well. Compared with the current Busan metropolitan area boundary, our empirical analysis captures the status quo of the undergoing spatial dynamics such as the newly form ed homogeneous sphere of living in our study area.

• The Journal of the Korea Contents Association
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• v.21 no.7
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• pp.171-180
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• 2021

Places exposed to mass media induce behavior by forming curiosity and expectations for potential travelers. The places reported through mass media influence viewers. Among TV programs, the most influential genre is drama, and reality programs that provide immersion with different characteristics from dramas influence viewers' choice of destination. CVM is mainly used for estimating the value of objects that cannot be evaluated in the market, such as tourist destinations. This study conducted an economic valuation of filming locations for dramas and travel entertainment programs using CVM, and then compared and analyzed the research results of the two filming locations. Linear and log logit analysis were performed to measure the willingness to pay for the filming location of the drama/travel entertainment program, and the payment amount was derived. The conclusion of the study is that as the travel cost required to visit the filming location of the drama/travel entertainment program increased, the intention to visit decreased. The amount payable when visiting the filming location of the drama/travel entertainment program was higher than the average consumption amount for a day trip, and the amount payable for the drama was higher than that of visiting the filming location of the travel entertainment program.

• Journal of People, Plants, and Environment
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• v.22 no.6
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• pp.629-639
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• 2019

This study was conducted to analyze the characteristics of visitors to Hadong Bukcheon Iceland Poppy (BIP) Festival in order to sustain and enhance local flower festivals as a garden tourism. A questionnaire was distributed to BIP Festival visitors from May 18 to 27, 2018. A total of 167 responses were subject to be analyzed. Descriptive statistics analysis was mainly used and focused on describing the results in direct to explain the BIP Festival as a garden tourism. The number of female visitors and those in their 40s and 50s was high. Most of the visitors were found to live in other cities or counties near the area where BIP Festival was held and to prefer festivals held on the theme of nature and local features. The revisit rate and awareness of BIP Festival were 52.1% and 72.5% respectively. They mainly obtained the information on BIP Festival from people around them including family members, friends and colleagues, or from the Internet. Most answered that BIP festival was the most important destination on their trip. The major motives of BIP Festival visit included "spending quality time with family or friends (34.1%)", "appreciating Iceland poppy and gardens (25.6%)", and "enjoying oneself (tranquility, mental rest, etc.; 21.3%). As a companion, family and friends/colleagues accounted for 62.3% and 26.3% respectively. Most were found to spend 1-2 hours on visiting BIP festival and stay in Hadong county for a quarter of a day. In satisfaction of BIP Festival itself, "display and maintenance of Iceland poppy (3.76)" and "easiness of viewing (places arrangement, path, etc.) (3.57)" were high. In satisfaction of public relation and information, "service and hospitality of guides and desk clerks (3.66)" was high. The intention to revisit BIP Festival was nearly affirmative (3.73-3.80).