• Journal of the Korean Society of Marine Environment & Safety
• /
• v.25 no.4
• /
• pp.504-510
• /
• 2019

Practical test items were analyzed to extend the existing scoring method for boat operator licenses to an electronic scoring method. We have attempted to digitize the method within the current practical test system scope and have developed an electronic scoring system using LiDAR sensors and WAVE communication. The results of the study are as follows; the first, the scoring data entered into the LiDAR and examiner score device on the boat were transferred from an integrated processing unit to a land control center through WAVE communication. The system was constructed and verified to store and manage examinee data. Second, when testing the meandering task, accurate distance measurement was achieved by using LiDAR instead of visually observing the stick (3 m), and an accurate distance was displayed through the examiner score device quickly. Finally, we confirmed that it is possible to smoothly transmit and process the WAVE communication used to transfer the score data acquired from the boat to the monitoring center at a high speed without loss.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2020.06a
• /
• pp.88-88
• /
• 2020

수심평균 2차원 혼합모형은 하천환경에서 다양한 용존성 오염물질의 혼합현상을 모의하기 위해 널리 활용되어왔다. 2차원 혼합모형에서 분산계수는 하천의 전단 흐름에 의해 야기되는 오염물질의 퍼짐 현상을 표현하는 중요한 인자로서 작용하기 때문에 정교한 오염물질 혼합거동을 모의하기 위해서는 적합한 분산계수를 산정하는 것이 필수적이다. 분산계수를 실험적으로 산정하는 방법으로는 크게 모멘트법과 추적법으로 나뉘며, 비정상상태의 혼합거동에 대해 종방향 및 횡방향 분산계수를 동시에 산정할 수 있는 방법은 추적법 계열의 2차원 유관추적법(2D STRP)이 유일하다. 본 연구에서는 하천에 유입된 오염물질의 2차원 혼합해석을 위한 수치모형을 개발하였으며, 개발된 모형의 수치해를 바탕으로 다양한 Peclet 수의 범위에 대해 기존연구에서 제시된 2D STRP의 적용범위 및 성능을 정량적으로 분석하였다. 분석된 정보를 바탕으로 기존 2D STRP의 한계를 극복하기 위한 개선된 2차원 유관추적법(2D STRP-i)을 개발하고, 사행하천을 모형화한 실규모 하천실험시설에서 검증하였다. 기존 2D STRP의 성능평가 결과, Peclet 수가 낮은 조건일수록 농도분포의 예측 정확도가 감소하는 경향을 보였으며, 하안 경계에 도달하는 농도가 증가할수록 부정확한 결과를 초래하는 것으로 나타났다. 본 연구에서는 기존 2D STRP의 한계를 보완하여 더욱 정확한 분산계수를 산정하고자 하안 경계면 조건을 고려한 2차원 유관추적법(2D STRP-i)을 개발하였다. 2D STRP-i는 직교-곡선좌표계 기반의 2차원 이송-분산 방정식을 바탕으로 횡방향 유속분포 및 하안 경계조건을 고려할 수 있도록 개선되었다. 2D STRP-i는 공간적으로 상이한 이송효과 및 하안경계 조건을 적절히 반영함으로써 농도분포의 예측 정확도를 개선 시키는 것으로 평가되었으며, 하안경계면에서 농도가 증가하는 구간에서 기존 2D STRP의 결과와 비교하여 더욱 정확한 농도분포 및 분산계수를 제공하는 것으로 밝혀졌다.

• Journal of Korea Water Resources Association
• /
• v.45 no.5
• /
• pp.445-454
• /
• 2012

The present study aims to investigate the long-term channel morphological changes derived from channelization, embankment and levee construction works in unregulated fluvial channel of the Jiseock River. Analyses of aerial photographs taken past (Year 1966) and recent (Year 2002) showed the temporally remarkable changes in channel planform such as channel shape, bar migration, vegetation encroachment in bar. During the period, the natural single threading changed into braided types together with decreasing sinuosity by 9.2%, increasing vegetation occupied bar ranged 97% of total bars area. Because such channel morphological changes are closely similar to those in dam downstream channels, we assume that both/either flow regime alteration and/or sediment transport discontinuity may be critical for the fixed channel and spread of vegetated bars even in unregulated river without dam reservoir upstream. We found more reduced frequency and magnitude of flooding water level comparing with past, but no significant alteration of inter annual water level variation. Bed material has been coarsened by 4~5 times and the riverbed has been degraded in overall channel but aggraded locally in conjunction reach of tributaries. The results indicates that reduced sediment dynamics in fluvial channel which derived by bed material coarsening, river bed degradation and unbalanced sediment transport capacity between tributary and mainstem can be a causal factor to trigger channel morphological changes even in unregulated rivers.

• Korean Journal of Environment and Ecology
• /
• v.22 no.6
• /
• pp.658-665
• /
• 2008

One of the characteristics of fluvial river channel with sand bed-material is the existence of movable sand bars not occupied with vegetation. However, sand bars at the Hahoe's reach of the Nakdong River showing a double-meandering channel has been changed into expanding vegetation area. Moreover, sand material, in recent years, has stopped moving to downstream in channel and the number and area of bare bars which did not occupied by vegetation have been decreased. In order to find out the mechanism, we carried out the channel characteristics surveys such as hydro-geomorphologic, soil physio-chemical and vegetation surveys were conducted twice on autumn season in 2005,2006. The results so far achieved showed that the reduced discharge of transported sediment and duration of dry season might be critical factors for the spread of luxuriant vegetation. The vegetation area was significantly expanded by floods exceeding the subsequent dominant flow discharge. Furthermore, the expansion of vegetation area was highly correlated with the supply of organic matter, nutrients and alteration of soil texture by sediment deposition during the flooding event.

• Journal of Korea Spatial Information System Society
• /
• v.10 no.4
• /
• pp.27-35
• /
• 2008

Current re-arrangement of rivers and waterways have been made uniformly ignoring characteristics of individual rivers thereby aggravating artificial river restructuring. On the contrary, quantitative techniques to evaluate the aftermath of artificial river disturbance such as uprising of river bed, intrusion of foreign fisheries, and changes of ecological habitats are not available. To establish such quantitative techniques, analysis of the river changes to evaluate the major causes of the river disturbance and its impacts is essential. Therefore, research for proposing a method which can be applied for the development of techniques to investigate river disturbance according to the major factors for the domestic rivers using airphotos and GIS techniques was preceded. In this study, the study area on the downstream of the river was selected and analysis of river disturbance using preceding method was done to confirm the benefit of analyzing river disturbance using GIS techniques. Trend analysis of the waterway sinuosity and changes of the flow path leaded to detailed verification of the river disturbance for specific location or time period, and this enabled to generate relatively accurate numbers representing sinuosity of the waterway and relevant changes. Also, it is possible to predict the effect on the current re-arrangement of the river and waterway to river flow using the analysis of past river change. It is necessary to establish GIS based proper measures for environmental river restoration using the results from this study and future works.

• Knowledge Management Research
• /
• v.23 no.3
• /
• pp.23-44
• /
• 2022

With the development of blockchain technology, play-to-earn (P2E) games, one of the decentralized applications (dApps), are receiving great social attention. P2E games are positively evaluated as areas with high growth potential based on blockchain technology, and at the same time, they are negatively evaluated as speculative as people can cash P2E game items in the form of cryptocurrency. In this situation, the purpose of this study is to investigate factors affecting the intention to use P2E games. Along with the discussion of hedonic system adoption, we consider the factors with perceived enjoyment, economic incentive, and social influence. In order to verify our research model, data were collected from 350 adults with P2E game experience or recognition, and a structural equation model was carried out. The analysis results find that perceived enjoyment and subjective norm have a significant positive effect on the intention to use P2E games, and economic incentive does not have a significant effect. In addition, peer influence and external influence have a significant positive effect on subjective norm. Drawing on these findings, we present several academic and practical implications for future research.

• Korean Journal of Culture and Social Issue
• /
• v.16 no.3
• /
• pp.241-265
• /
• 2010

This study reviewed the present state and differences of rehabilitation programs of the gambling addiction by comparing with other psychiatric disorder(including psychotic disability and alcohol addiction). This study also intended to suggest necessities, meanings and inherent fields of the rehabilitation in gambling addiction. First of all, the government and a few gambling industries run clinic centers for gamblers and their families, but have been lacked rehabilitation services for social comeback and adaptation or devaluated rehabilitation services than therapies. Gambling addict didn't have impairments of the cognitive function and their daily abilities was better than any other psychiatric disorders. But Damage of social role or function of gambling addiction was severe. And it is caused by nonadaptive nature of gambling behavior, personality/emotional change through gambling addiction process, and previous personality problem etc. There are many severe failure of social role and its attendant bankrupcy, family's problems and social poverty in gambling addiction, Therefore, important fields in the rehabilitation of gambling addiction should be services for basic social comeback support service, credit recovery support, monetary management, support of rehabilitation of family and vocational rehabilitation. Finally, the significance and critical points of the current study has been discussed as well.

• Korean Journal of Heritage: History & Science
• /
• v.56 no.1
• /
• pp.142-160
• /
• 2023

The position of the people who participated in the Bapyo Ritual held in the reign of King Sejong and the corresponding costumes were examined. The king, who was the executive body of the ritual, wore Myeon-Bok, a court dress, and Myeon-Bok was Gujang-Bok made of Jang-wha on Guryu-Pyeongcheongwan. Crown princes, royal families, and government officials wore Oryang-Gwan and Jekraeui, which were Jobok. The crown princes' Joboks were changed from Oryang-Gwan to Wukryang-Gwan in the dynasty year 10 of King Sejong, and in the year of King Munjong's accession, Myeon-Bok was received, and after King Danjong, the crown princes wore Palryu-Pyeongcheongwan and Chiljang-Bok. Diplomats and Jongsagwan who were the envoys wore Sangbok. A Sangbok worn by the diplomat was Samo with Danryeong, Seo-Dae, and Hyeopgeum-Hwa, and a Sangbok worn by Jongsagwan was Samo, Danryeong, Heukgak-Dae, and Heukpi-Hwa. Byulgam, who served as an attendant to the king in the king's close quarters, wore Gongbok and Sangbok. Gongbok consisted of Ja-Geon, Danryeong and Heukpi-Hwa, and Sangbok consisted of orange color Cho-Rip, Jikryeong, Joa, and Heukpi-Hwa. The person holding San, Gae , Sujeongjang, and Geumwolbu wore Ja-Geon and Cheong-Ui, and Seon wore Pimoja and Hong-Ui. Siwigun wore armor and helmets equipped with weapons. Among court musicians, Aksa's costumes consisted of Bokdu, Bigongbok, Geumdonghyeokdae, Bibaekdaedae, and Opiri, and Aksaeng's one composed of Gaechaek, Bisuransam, Hyupgo, Mal, Maldae, and Opiri. As a result of the above, the process of ceremonial clothes becoming uniform clothes in the reign of King Sejong was confirmed. The king and lower-ranking officials such as crown princes, government officials, diplomats, Byulgam, armies for ceremonial weaponry, and court musicians participating in the Bapyo Ritual wore the highest grade of ceremonial clothes for each class. King Sejong had repeated discussions to build a nation based on Confucianism, and arranged each rite and corresponding costume, and the Bapyo Ritual costume was also systematically prepared for each position. The ceremonial clothing organized during the reign of King Sejong was regulated in Yejon and became the basis for continuing to the late Joseon Dynasty.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.39 no.3
• /
• pp.10-25
• /
• 2011

Since 1950, the city of Yokohama has been demanding the return of US. military base sites in Yokohama. Yokohama has established a systematic utilization plan for these relocation sites. The Fukaya communication site is one of former US. military bases verified for return in 2004. The Fukaya communication site is distinctively circular in shape and is entirely national land. Yokohama took an idea competition to its citizens to create a new park at the relocation of the Fukaya communication site, involving lots of citizen opinion in its utilization goals. This study determined the process of the idea competition at the Fukaya communication site in encouraging civic participation and analyzing citizen demands for the utilization of the relocation site. Through the idea competition, Yokohama city was able to obtain several ideas on the new park from various angles such as the function and shape of the urban open spaces. Citizens showed great interest in creating a park as green infrastructure on the Fukaya communication site. In addition, beyond utilization as an urban open space, many ideas suggested new lifestyles for the region in connection with the natural environment in the vicinity. Yokohama city tried to share the process and results of the idea competition with as many citizens as it could through a variety of means such as Participation, Judging, Support, Observation and Understanding. The case study on the idea competition at the Fukaya communication site is a good example of community design practice in public projects, and is full of suggestions for military bases in Korea, which has just established the plan of utilizing relocation sites as parks. Based on this case study, it can be concluded that it is important to make a systemic form for utilization planning with a clear process, open information and partnership in a variety of participatory design processes in order to ensure maximum civic utilization of relocation sites.

• Journal of Wetlands Research
• /
• v.22 no.3
• /
• pp.194-199
• /
• 2020

Unlike in the past, the world is facing water shortages due to climate change and difficulties in simultaneously managing the risks of flooding. The Four Major Rivers project was carried out with the aim of realizing a powerful nation of water by managing water resources and fostering the water industry, and the construction period was relatively short compared to the unprecedented scale. Therefore, the prediction and analysis of how the river environment changes after the Four Major Rivers Project is insufficient. Currently, part of the construction section of the Four Major Rivers Project is caused by repeated erosion and sedimentation due to the effects of sandification caused by large dredging and flood-time reservoirs, and the head erosion of the tributaries occurs. In order to solve these problems, the riverbed maintenance work was installed, but it resulted in erosion of both sides of the river and the development of new approaches and techniques to keep the river bed stable, such as erosion and excessive sedimentation, is required. The water agent plays a role of securing a certain depth of water for the main stream by concentrating the flow so much in the center and preventing levee erosion by controlling the flow direction and flow velocity. In addition, Groyne products provide various ecological environments by forming a natural form of riverbeds by inducing local erosion and deposition in addition to the protection functions of the river bank and embankment. Therefore, after reviewing the method of determining the shape of the Groyne structure currently in use by utilizing the mobile limit flow rate and marginal reflux force, a new Critical Movement Velocity(${\bar{U}}_d$) and a new resistance coefficient formula considering the mathematical factors applicable to the actual domestic stream were developed and the measures applicable to Groyne installation were proposed.