• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.277-277
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• 2022

급경사 산지하천은 호우 시 퇴적 하상이 붕괴하여 하천 유사량을 급격히 증가시키는 계곡형 토석류가 발생하고 도로와 교량에 피해를 일으키기도 한다. 이러한 하천재해를 저감하기 위하여 돌망태 낙차공을 설치하여 하상 안정을 강화하고 급경사에 따른 유수에너지를 줄일 수 있다. 급경사 하상에 설치한 돌망태 낙차공은 하류부 하상의 국부세굴에 따른 파괴위험이 완경사 하상의 경우에 비하여 높으므로 이를 줄이기 위한 연구가 필요하다. 이 연구에서는 광폭경사조절 개수로에 돌망태 낙차공을 설치하고 낙차공의 채움재가 복류의 특성에 미치는 영향을 파악하기 위하여 수리실험을 하였다. 수리실험에서는 최대 20º까지 경사를 조절할 수 있는 길이 1.44m, 폭 0.14m인 직사각형 단면 개수로에 SUS304 구슬을 사용하여 하상과 돌망태 낙차공을 설치하고 실험하였다. 구슬은 크기에 따라 작은구슬(10.31mm), 중간구슬(15.08mm), 큰구슬(20.63mm)을 사용하고, 하상에는 작은구슬을 깔았다. 낙차공의 크기는 길이 16cm이고 폭과 높이는 12cm이며, 돌망태는 작은구슬을 사용한 단일돌망태와 구슬 크기를 달리한 계층돌망태로 구분하였다. 계층돌망태의 상층은 작은구슬, 중층은 중간구슬, 하층은 큰구슬이 채움재로 사용되었다. 단일돌망태의 공극율은 0.399이고 계층돌망태의 공극률은 상층 0.393, 중층 0.517, 하층 0.54이다. 실험유량의 변화는 낙차공 하단부에서 표면류가 발생하지 않는 범위로 한정하였다. 낙차공 하단에서 상류 68cm 지점의 소류력과 낙차공 내부 복류의 수면경사를 측정하였다. 그 결과 단일돌망태보다 계층돌망태가 소류력과 수면경사가 더 작은 것으로 나타났으며 돌망태의 공극을 통한 통수능 차이 때문인 것으로 판단된다.

• KOMUNHWA
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• no.70
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• pp.109-132
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• 2007

Taking the Yosu Peninsula where prestige goods were prevalent and more dolmen were excavated and surveyed than other regions as object of the research, this dissertation investigated the hierarchy of dolmen society. The dolmen groups were excavated and surveyed at some 20 positions in Yosu Peninsula Analyzing the number, weight of upper stone, location, the buried relics of dolmen, the hierarchy for each dolmen group can be summarized as follows. It seems that the large group with a lot of dolmen and big upper stone which is located on the plane with stream or on the lower part of hill might be the central group with abundant buried relics. However, the size of individual upper stone does not coincide with buried relics sometimes. Thus, it is required to review the entirety of dolmen group rather than individual upper stone in the relation between the scale of upper stone and buried relics. Then the scale of tomb is proportionate to the prestige goods. Meanwhile, the discrepancy between dolmens can be verified by the difference among upper stone, tomb, burial accessories, etc in the unit dolmen group. Since dolmen is the tomb of some inhabitants in the Bronze Age, the existence of stone coffin tomb with buried bronze sword, jade or stone sword compared to the stone coffin with no relics means that there was powerful representative of one generation even in one kindred group on the basis of wealth or authority. It can be concluded that the upper stone or large tomb or prestige goods among the persons buried in dolmen were fixed as high class, those with relatively small stone coffin with no or scanty burial accessories were fixed as medium class and multitudinous class who were not buried in dolmen were fixed as low class. Therefore, the dolmen society in Yosu Peninsula shows that there was division of class in the unit dolmen group as well as hierarchy in the group.

• Journal of Korea Port Economic Association
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• v.32 no.3
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• pp.155-175
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• 2016

The purpose of this paper is to find the success factors for a newly developed marine financial city of Busan. For this, in the paper, we did case studies about advanced marine financial cities such as Hamburg, Oslo, Pireus, Shanghai, Singapore and London. And we made the hierarchical questionnaire for this study from literature reviews and interviews with experts in the field of the marine finance. A hierarchy was made up of 4 factors as the first class and the each factor consisted of four elements as the second class. The results of AHP analysis are as follows. First, the most important factor in the priorities with respect to marine financial city of Busan is "development of marine finance(0.371)" within the four factors as the first class. Next came "business environment(0.248)", "infrastructure(0.206)" and "support of government(0.175)". Second, the most important things is a clustering for marine finance(0.134) within 16 elements as the second class. We also analysed the priorities by the each factor of the second class. The most important element is an industrial clustering of marine finance(0.400) for "development of marine finance" and a clustering of the shipbuilding & marine industry(0.175) for "business environment" factor. And the ICT & transportation(0.326) is the most important element for "infrastructure" and a support of the national government(0.423) for "support of government" factor.

• Journal of Convergence for Information Technology
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• v.11 no.4
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• pp.26-34
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• 2021

In the era of the Fourth Industrial Revolution, the future battlefield will carry out multi-area operations with hyper-connected, high-speed and mobile systems. In order to prepare for changes in the future, the Korean military intends to develop various weapons systems and form a multi-layer tactical network to support On The Move communication. However, current tactical networks are limited in support of On The Move communications. In other words, the operation of multi-beam antennas is necessary to efficiently construct a multi-layer tactical network in future warfare. Therefore, in this paper, we look at the need for multi-beam antennas through the operational scenario of a multi-layer tactical network. In addition, based on development consideration factors, features of rotary-wing and fixed-wing aircraft, we present the location and operation of airborne relay drone installations of multi-beam antennas.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.4
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• pp.145-166
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• 2023

The ongoing COVID-19 pandemic has led to a widespread shift towards non-face-to-face/uncrewed services in various sectors of society. Despite this, research on the digital divide has focused predominantly on analyzing various factors, with the notable absence of studies addressing the digital divide. Therefore, study examined the current digital divide in the transportation sector through a survey-based approach. First, a nationwide survey was conducted among adult men and women to assess their digital device usage. Vulnerable groups sesceptible to digital disparities were identified based on factors such as age, education, and income. Second, comparative analysis was conducted to examine the usage patterns of mobile applications related to the transportation sector among the vulnerable and non-vulnerable groups using chi-squared test. These findings suggest that the vulnerable group exhibited lower awareness and preference for mobile applications, a significantly lower frequency of application usage than the non-vulnerable group. Finally, a comparison of the proficiency in utilizing transportation sector mobile applications was conducted, showing that the vulnerable group demonstrated a significantly lower level of proficiency across all aspects of application usage procedures compared to the non-vulnerable group. These survey results provide a valuable foundation for future policy formulation to reduce the digital divide in the transportation sector. By highlighting the current state of digital disparities, the research contributes to developing evidence-based strategies to enhance inclusivity and equal access to digital services in tjwtransportation.

• Journal of Korea Multimedia Society
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• v.9 no.9
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• pp.1231-1246
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• 2006

HTML is a format for rendering Web documents visually and uses tables to present a relational information. Since HTML has limits in terms of information processing and management by a computer, it is important to transform HTML tables into XML documents, which is able to represent logical structure information. As a prerequisite for extracting information from the Web, this paper presents an efficient method for extracting logical structures from HTML tables and transforming them into XML documents. The proposed method consists of two phases: Area segmentation and structure analysis. The area segmentation step removes noisy areas and extracts attribute and value areas through visual and semantic coherency checkup. The hierarchical structure between attribute and value areas are analyzed and transformed into XML representations using a proposed table model. Experimental results with 1,180 HTML tables show that the proposed method performs better than the conventional method, resulting in an average precision of 86.7%.

• Journal of the Korean Geographical Society
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• v.45 no.5
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• pp.592-608
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• 2010

This study investigates the diurnal pattern of transit ridership in the Metropolitan Seoul area. For the purpose, we use a weekday Smart Card passenger transaction data in 2005. Eleven passenger trip patterns are found from 2.74 million passengers moving on the Metropolitan Seoul Metro system. Among them, we analyze 2.4 million passengers blonging to five trip types having only one or two transaction record during a day. A total of 357 metro stations are classified to four types according to their diurnal pattern of passenger riderships. We analyze the relationships between passenger's trip chain patterns and subway station's diurnal transit ridership patterns. The result shows that the ratio of the number of passengers of particular time of the day is hierarchically related with trip chain patterns.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.1
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• pp.169-174
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• 2018

There are many CCTV cameras connected to the video surveillance and monitoring center for the safety of citizens, and it is difficult for a few monitoring agents to monitor many channels of videos. In this paper, we propose an intelligent video surveillance system utilizing a safety map to efficiently monitor many channels of CCTV camera videos. The safety map establishes the frequency of crime occurrence as a database, expresses the degree of crime risk and makes it possible for agents of the video surveillance center to pay attention when a woman enters the crime risk area. The proposed gender classification method is processed in the order of pedestrian detection, tracking and classification with deep training. The pedestrian detection and tracking uses Adaboost algorithm and probabilistic data association filter, respectively. In order to classify the gender of the pedestrian, relatively simple AlexNet is applied to determine gender. Experimental results show that the proposed gender classification method is more effective than the conventional algorithm. In addition, the results of implementation of intelligent video security system combined with safety map are introduced.

• Korean Journal of Agricultural and Forest Meteorology
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• v.21 no.4
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• pp.286-296
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• 2019

Land suitability assessments have been a crucial issue for enhancing productivity in agriculture and conserving agricultural lands. Based on soil and climate information, land suitability assessment for peaches (Prunus persica) and grapes (Vitis vinifera L.) were conducted using the maximum limiting characteristic method (MLCM) in South Korea. In peaches, S1 (highly suitable) exists on 2.21% of the land, S2 (moderately suitable) on 19.20%, N1 (currently not suitable) on 12.07%, and N2 (permanently not suitable) on the remaining 66.52%. In grapes, 3.65% of the land is classified as S1, 17.98% as S2, 11.85% as N1 and 66.52% as N2. In both fruit trees, the results acquired from soil and climatic information were similar to those from soil information alone. The data also suggest that the grades by soil information were relatively low over the land. With the assumption that the more suitable area a province has, the more will be cultivated for the fruit trees, we compared the percentages of area for peach and grape farming per province with the results by MLCM, and suggested that some provinces with a small percentage of farm can be encouraged to plant more in suitable areas as dictated by MLCM for the species. In the near future, we plan to use an advanced method such as analytic hierarchy process (AHP) to conduct similar tests, in which having reference data of yields or benefits per farm can efficiently increase the accuracy of the measurements.

• The Transactions of the Korea Information Processing Society
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• v.4 no.4
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• pp.1059-1075
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• 1997

The transprot layer protocol for distrubuted multimedia applications in high speed network should gurantee the Quality of Serivce(QoS)requested by uwer.,The QoS Parmenters can be divied into two calssifications:those depend on the speed of a network such as bandiwidth,end-to-end transmission delay and throughput;and net- woek independent parameters such as various typed of group communications, retransmission method based on multimeda characteristic,acceptable packet wrror rate and transmission priority.In this proposed protocol,we divided user's QoS into performance redated parmeters and non-performance related parameters.The perform- ance-related paramenters are mapped into ATM traddic paramenters by the Distributed QoS Manger(DQM),the QoS manager,and the non-performance redlted paramenters are supported by the Distributed Multimedia Trans-port protocol(DMTP),a high-performance group transport protocol.Especially,becaues the DMTP is designed with considering the IP protocol,it can be efficiently used as an underlying protocol not onlu in ATM,but also in Ethernet,Token ring and FDDI LAN.