• Journal of Information Processing Systems
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• 제16권4호
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• pp.896-914
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• 2020

With the rapid growth of network traffic, a large number of connected devices, and higher application services, the traditional network is facing several challenges. In addition to improving the current network architecture and hardware specifications, effective resource management means the development trend of 5G. Although many existing potential technologies have been proposed to solve the some of 5G challenges, such as multiple-input multiple-output (MIMO), software-defined networking (SDN), network functions virtualization (NFV), edge computing, millimeter-wave, etc., research studies in 5G continue to enrich its function and move toward B5G mobile networks. In this paper, focusing on the resource allocation issues of 5G core networks and radio access networks, we address the latest technological developments and discuss the current challenges for resource management in 5G.

• 전자통신동향분석
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• 제34권6호
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• pp.71-86
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• 2019

The unprecedented demands of mobile communication networks by the rapid rising popularity of mobile applications and services require future networks to support the exploding mobile traffic volumes, the real time extraction of fine-rained analytics, and the agile management of network resources, so as to maximize user experience. To fulfill these needs, research on the use of emerging deep learning techniques in future mobile systems has recently emerged; as such, this study deals with deep learning based mobile communication research activities. A thorough survey of the literature, conference, and workshops on deep learning for mobile communication networks is conducted. Finally, concluding remarks describe the major future research directions in this field.

• 한국항공운항학회지
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• 제29권3호
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• pp.15-23
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• 2021

Personal Air Vehicle is expected to be a promising solution to relieve traffic congestion using urban airspace. The development of related technologies such as materials or batteries has been accelerated. In addition, commercial transportation services are being prepared. When fierce competition begins in the PAV market, even technologically superior products will disappear without choices by consumers. Therefore, demand factors should be reflected in PAV development to enhance competitiveness. In the paper, values were estimated for the major technological attributes of PAV. Stated preference data were collected through a survey, and the conjoint method and ordered probit model were adopted. Thereafter, it was confirmed that the value would be high in the order of dual mode, drone-type appearance, and noise reduction. Some R&D strategies were proposed based on this.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 봄 학술논문 발표대회
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• pp.210-211
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• 2022

Pruning is the most important work for the growth and aesthetics of street trees. It is also the most actively conducted maintenance work. However, the specifications, application methods, and cost criteria for pruning have not been systematically established. This has recently caused a lot of confusion in the practice of street tree pruning, such as indiscriminate pruning and lack of construction costs. Therefore, this study clarified the contents of work according to the form of pruning. It added 'aesthetic pruning,' which takes into account design. In addition, It revised equipment not in conformity with the law and excluded personnel necessary for on-site traffic control so that they could be reflected separately. As a result, this study is expected to contribute a lot to securing appropriate construction costs for maintaining street trees.

• 해양환경안전학회지
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• 제19권3호
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• pp.248-256
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• 2013

Part 2 of the Questionnaire Survey on Marine Safety and VTS in the Philippine Coastal Waters presents the alternatives to risk reduction, modifying the VTS, the qualification and competency of a VTS operator and effectiveness of the services and assistance rendered by VTS. This study finds that majority of respondents chose "Improved education and training of mariners" as the best alternative to risk reduction and the "Strict enforcement of ship safety regulations" as the best alternative based on the respondents' ranks last served onboard and areas of familiarity. In modifying the VTS, the areas with VTS chose to "Improve or upgrade" and for those without, is to "Implement" the system. The best VTS system is the "Port and Approaches" type and the PCG is selected to operate, maintain and supervise the system. As a VTS operator, the necessity of shipboard experience is considered "Essential" and the experiences include "Ship-handling and Communication", and "Management level" experiences. The effectiveness of the assistance and services rendered by VTS are considered "Very Important". Based on these findings, this study recommends improvement of education and training of mariners and users of the waterways including the training of VTS operators manning the VTS centers, strict enforcement of ship safety regulations along the busy and main ports of the country and installation of VTS system with the most appropriate type with the supervision of PCG.

• 대한토목학회논문집
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• 제34권2호
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• pp.573-582
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• 2014

교차로에 인접한 부 도로에 대한 설치기준이 명확하지 않아 설치 및 운영에 많은 문제점을 야기시키고 있으며, 이로 인하여 교통소통과 교통안전에 문제가 발생하고 있다. 현재까지 교차로 진출입과 관련하여 운영적인 측면에서는 많은 연구가 시도되었지만, 교차로에 인접한 부 도로에 대한 연구는 대단히 미흡하고 이에 따른 합리적인 설계가 이루어지지 못하는 실정이다. 이에 본 연구에서는 교차로에 인접한 부 도로에서 진출하는 차량에 대한 행태를 조사하고, 교통소통과 안전을 고려하여 교차로에 인접한 부 도로의 적절한 이격거리를 제시하고자 한다. 교통소통과 안전을 도모할 수 있는 교차로에 인접한 부 도로의 적정길이를 제시함으로써, 향후 교차로에 인접한 부 도로와과 관련된 설치기준 정립에 이바지하고자 한다.

• 대한교통학회지
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• 제33권3호
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• pp.276-283
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• 2015

각 도시에서는 급증하는 자동차로 인해 보행자의 영역은 줄어들고 있고 보행자를 위한 도로시설의 개선은 향상되지 못하고 있어 보행자는 위험한 교통환경에 노출되고 있다. 이러한 열악한 보행환경은 비교통약자에게도 위험하지만 교통약자에게는 더욱 치명적인 위험요소가 될 수 있다. 본 연구에서는 교통약자의 교통안전을 향상시키고 보행환경을 개선하기 위해 교통약자 유형별로 도로시설 이용특성을 분석하였다. 본 연구의 방법은 교통약자를 대상으로 기존 도로의 보행시설을 이용할 때 느낀 정량적, 정성적 사항에 대한 설문조사를 실시하고 이를 바탕으로 정량적, 정성적 요소를 모두 고려한 의사결정방법인 계층 분석적 의사결정방법(AHP)을 이용한 연구를 수행하였다. 제3계층 분석결과 고령자나 장애인의 경우 일부 유사한 특성을 나타내고 있었으며 차량진출입, 도로의 기울기나 포장불량이 높은 순위의 불편요소로 나타났다. 영유아동반자의 경우 승강기가 없는 육교와 지하도가 1순위로 나타나 고령자, 장애인과 다소 차이가 있는 것으로 분석되었다.

• 한국환경보건학회지
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• 제38권5호
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• pp.407-414
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• 2012

Objectives: This study was performed to assess based on field investigation the distribution characteristics of airborne fungi in an area of Seongdong-gu, Seoul. Methods: Three sites, a living area, forest and traffic site, were selected for evaluation of monthly level of outdoor airborne fungi. An on-site survey was executed between January 2009 and December 2009. During the experimental period, air sampling was performed every month in the afternoon (2:00 pm-5:00 pm) using a cascade impactor. Results: Outdoor airborne fungi measured in Seoul, Korea over one year showed a concentration range from 850CFU $m^{-3}$ to 15,200CFU $m^{-3}$. The mean respirable fraction of outdoor airborne fungi was 67% compared to total concentration. Regardless of measurement site, there was no significant concentration difference in outdoor airborne fungi between periods of yellow dust and non-yellow dust (p>0.05). There was no significant correlation relationship between outdoor airborne fungi and atmospheric factors such as temperature and relative humidity. The predominant genera of airborne fungi identified were Aspergillus, Cladosporium, Paecilomyces and Penicillium. Conclusion: Monthly levels of outdoor airborne fungi were highest in April and November and lowest in August. In seasonal concentration distribution, the autumn showed the highest level of outdoor airborne fungi, followed by spring, summer and winter. In regional concentration distribution, the highest level of outdoor airborne fungi was generally found in the forest, followed by the living area and traffic site.

• 한국산학기술학회논문지
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• 제11권12호
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• pp.4795-4802
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• 2010

제주지역의 교통문제 해결을 위해서는 승용차 통행자의 수요를 줄임과 동시에 이들을 대중교통으로 전환시키기 위한 각종 정책과 대중교통 서비스의 질적 향상이 절실하게 필요하다. 본 연구에서는 제주지역 통행자들의 개인특성 요인과 교통수단 선택과의 관계, 개인의 효용 요인인 통행비용과 통행시간이 교통수단 선택에 미치는 영향에 대해 알아봄으로써 승용차 통행자를 버스로 전환시키기 위한 대중교통 노선 개편 시 고려해야 할 요인에 관한 기초자료로 활용 될 수 있을 뿐만 아니라 대중교통서비스의 질적 향상에 기여할 수 있을 것으로 기대된다. 이러한 연구의 수행을 위해 2010년 5월에 설문조사를 실시하였고, 다항 로짓분석을 실시하였다. 분석결과 자택을 소유한 통행자와 가구의 가족수가 5명 이상인 통행자는 승용차를 이용할 가능성이 높고, 통행시간이 길어지면 버스를 이용할 가능성이 높은 반면에 통행비용이 증가하면 승용차를 이용할 가능성이 증가함을 알 수 있었다.

• 한국소음진동공학회논문집
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• 제17권5호
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• pp.437-447
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• 2007

A series of research to seek for the relationship between subjective responses and noise level for transportation noise have been proceeded, and their results showed similar for some cases and different for some other cases as well, which is considered due to the various conditions such as the way of survey, different scale applied, and country etc. This study aimed to analyze the relationship between sound level and subjective response for the different kinds of transportation noise. The noises recorded in real situation were played to thirty subjects with fourty nine adjectives. The percentage of people annoyed(% PA) and the percentage of people highly annoyed(% HA) were calculated from the subjective results and compared how many percent of people are annoyed and highly annoyed for the same sound level. As a result of calculating the average, the aircraft noise was highest and the white noise lowest. The relationship between window TL and average point was well correlated except the aircraft noise which was scattered because of high sound level at specific frequency and low TL at corresponding frequency. This means that appropriate rating method for airborne sound transmission should be sought for to evaluate outdoor noise which has different frequency characteristics. The Boltzmann equation for % PA and % HA was applied to predict the sound level corresponding to the percentage. It is concluded that the aircraft noise and road traffic noise have almost same response and the railway noise was same with white noise, used for the reference noise, annoyed lower than other noises about by 3 dB.