• International Journal of Advanced Culture Technology
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• 제9권3호
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• pp.360-366
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• 2021

In this study, we tried to examine how the kinking of the fire hose affects the time taken for initial water discharge by measuring and analyzing the time taken for initial water discharge with different number of kinks at different locations of the hose. The average time taken for initial water discharge was obtained by measuring the time in the unkinked state of the fire hose. Based on this standard, we conducted the experiment by selecting the kinking locations in the hose near the water outlet and nozzle, and setting the number of kinks to 3, 6, 9, and 12. The results of this study are as follows: First, if the fire hose has 5 kinks or more near the nozzle, no water was released. Second, when comparing the case of no kinks and 4 kinks near the nozzle, there was no significant difference in the time taken for initial water discharge. Third, when the fire hose was kinked 10 times near the outlet, the time required for initial water discharge increased by 1.62 seconds on average compared to the case with no kinking, but there was no problem with water discharge. Lastly, regarding the kinking locations of the fire hose, it was found that the greater the number of kinks near the nozzle than near the outlet, the greater the effect on the discharge. As a result, it is concluded that it would be preferable to install non-kinking devices near the nozzle of the fire hose.

• 대한토목학회논문집
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• 제28권5D호
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• pp.723-734
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• 2008

본 연구는 부산시 지구단위계획의 유형을 바탕으로 유형별 사례대상지를 선정하여 지구단위계획의 운영상의 문제점과 개선방향에 대하여 고찰해보았다. 사례대상지의 선정은 유형별로 '기존시가지 정비형' 4개소, '기존시가지 관리형' 3개소를 각각 선정하였으며, 사례대상지를 선정함에 있어서 대상지의 규모와 입지적인 특성을 고려하였다. 사례지대상지 분석결과 제도적 측면에서는 용도지역의 무분별한 상향조절, 미미한 주민참여, 유형화에 대한 문제가 나타났으며, 계획적 측면에서는 기본방향과 목표의 유사성, 밀도계획의 일괄적인 적용, 용도계획에 부적절성, 건축물의 배치 및 형태, 색채계획 등에서의 문제점이 나타났다. 대상지 분석에서 나타난 문제점을 바탕으로 지구단위계획의 실효성 개선방안을 고찰해본 결과 제도적 측면에서는 용도지역 변경에 있어 변경 대상 및 범위에 대한 명확한 기준 설정이 시급하였으며, 계획적 측면에서는 지구단위계획의 유형 세분화에 따른 차별적인 세부 운영 지침(guideline)을 마련함으로서 지구단위계획의 기본방향과 목표가 각 유형의 목적달성을 위해 설정되도록 해야 하며, 건축물의 적정개발 밀도에 대한 명확하고 논리적인 기준 제시를 통해 건축물의 건폐율(the building-to-land ratio)이나 용적률(floor space index)을 적정하게 산정해야 함과 동시에 지구특성에 맞는 건축용도 분류를 통해 지구별로 특화된 기능을 유도하는 세부적인 건축물 용도계획이 이루어져야 하며, 건축물의 획일적인 형태를 지양하고 배치에 있어서도 가능한 개방감 있도록 계획해야 한다는 결과가 도출되었다.

• Journal of Advanced Marine Engineering and Technology
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• 제36권6호
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• pp.823-829
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• 2012

미래 해상데이터통신망은 광대역무선접속(BWA) 캐리어들이 중첩된 자율망(MANET)으로 모델링될 수 있다. 이러한 망 모델에서 응용 서비스별 캐리어 선호도와 선박의 위치를 함께 이용하고 경로의 홉단위 최적 캐리어를 선택하여 최적경로를 찾는 라우팅방식(CPLR)을 새롭게 제안한다. 이 방식에서는 경로의 각 선박과 목적지 선박간 거리를 고려하기 때문에 최적경로를 찾아가는 수렴성이 개선되어 라우팅 시간을 더 줄였다. 캐리어 선호도만을 고려하여 최적경로를 탐색하는 (CPR)방식과 성능을 비교하여 개선결과를 보였다.

• 센서학회지
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• 제10권5호
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• pp.286-291
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• 2001

논문에서는 임의의 시각계에서 인간과 유사한 시각 응시점을 선택하기 위한 Saliency map 모델을 제안한다. 제안하는 모델은 영상의 에지 정보를 시각 응시점 결정을 위한 특징 기저로 이용한다. 자연 정지 흑백 영상에서 상호 독립적인 에지 성분들을 찾는데 가장 좋은 방법이라고 알려진 독립성분해석 방법을 이용한다. 인간 시각계에서 시각 수용체의 비균일 분포를 고려하기 위해 카메라와 같은 시각 센서로 받은 영상을 직접 이용하는 대신에 입력 영상으로 다중 해상도를 갖는 계층 영상을 이용한다. 컴퓨터를 이용한 시뮬레이션으로부터 제안한 Saliency map을 이용하여 주어진 임의의 이미지에 대한 시각 응시점을 구한다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 22-24 Oct. 1991
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• pp.1939-1943
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• 1991

Path planning is an important task for optimal motion of a robot in structured or unstructured environment. The goal of this paper is to plan the shortest collision-free path in 3D, when a robot is navigated to pick up some tools or to repair some parts from various locations. To accomplish the goal of this paper, the Path Coordinator is proposed to have the capabilities of an obstacle avoidance strategy[3] and a traveling salesman problem strategy(TSP)[23]. The obstacle avoidance strategy is to plan the shortest collision-free path between each pair of n locations in 2D or in 3D. The TSP strategy is to compute a minimal system cost of a tour that is defined as a closed path navigating each location exactly once. The TSP strategy can be implemented by the Neural Network. The obstacle avoidance strategy in 2D can be implemented by the VGraph Algorithm. However, the VGraph Algorithm is not useful in 3D, because it can't compute the global optimality in 3D. Thus, the Path Coordinator is proposed to solve this problem, having the capabilities of selecting the optimal edges by the modified Genetic Algorithm[21] and computing the optimal nodes along the optimal edges by the Recursive Compensation Algorithm[5].

• 한국지구과학회지
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• 제24권1호
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• pp.1-6
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• 2003

In this work, the present concentration levels of total gaseous mercury (TGM) are compared among three East Asian countries, Korea, China, and Japan. Comparison of Hg distribution patterns was made by selecting representative figures for each type of land use among those three countries. The results of the analysis indicate that Hg concentrations within a country can fall into a wide range due probably to the diversity of source processes. It is seen that the urban areas of China and Japan generally exhibit large spatial variability with notably high Hg levels (above 10 ng m$^{-3}$), compared to their Korean counterparts. Although the presence of high Hg levels in Chinese locations can be accounted for by the major man-made source processes (e.g., the use of coal), the causes of unexpectedly high Hg data in Japanese sites appear to be rather complicated. The Hg concentration levels in relatively remote locations however show much reduced values, above 3 ng m$^{-3}$, which is still higher than the typical background concentrations of 1 to 2 ng m$^{-3}$ in Europe or America. Considering that the presence of unusually high Hg levels in urban areas of Asia is the consequence of man-made activities, the prevalence of excessively high Hg values in certain regions of the Asian continent needs further research to accurately assess the fundamental picture of Hg geochemistry in the East Asia.

• Smart Structures and Systems
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• 제4권5호
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• pp.629-640
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• 2008

A new algorithm is proposed to determine optimal accelerometer locations (OAL) when a structure is identified by frequency domain system identification (SI) method. As a result, a guideline is presented for selecting OAL which can reflect modal response of a structure properly. The guideline is to provide a minimum number of necessary accelerometers with the variation in the number of measurable target modes. To determine OAL for SI applications effectively, the modal sensitivity effective independence distribution vector (MS-EIDV) is developed with the likelihood function of measurements. By maximizing the likelihood of the occurrence of the measurements relative to the predictions, Fisher Information Matrix (FIM) is derived as a function of mode shape sensitivity. This paper also proposes a statistical approach in determining the structural parameters with a presumed parameter error which reflects the epistemic paradox between the determination of OAL and the application of a SI scheme. Numerical simulations have been carried out to examine the proposed OAL algorithm. A two-span multi-girder bridge and a two-span truss bridge were used for the simulation studies. To overcome a rank deficiency frequently occurred in inverting a FIM, the singular value decomposition scheme has been applied.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 19-21 Oct. 1992
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• pp.79-84
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• 1992

Path planning is an important task for optimal motion of a robot in structured or unstructured environment. The goal of this paper is to plan the optimal collision-free path in 3D, when a robot is navigated to pick up some tools or to repair some parts from various locations. To accomplish the goal, the Path Coordinator is proposed to have the capabilities of an obstacle avoidance strategy and a traveling salesman problem strategy (TSP). The obstacle avoidance strategy is to plan the shortest collision-free path between each pair of n locations in 2D or in 3D. The TSP strategy is to compute a minimal system cost of a tour that is defined as a closed path navigating each location exactly once. The TSP strategy can be implemented by the Hopfield Network. The obstacle avoidance strategy in 2D can be implemented by the VGraph Algorithm. However, the VGraph Algorithm is not useful in 3D, because it can't compute the global optimality in 3D. Thus, the Path Coordinator is used to solve this problem, having the capabilities of selecting the optimal edges by the modified Genetic Algorithm and computing the optimal nodes along the optimal edges by the Recursive Compensation Algorithm.

• The Journal of Asian Finance, Economics and Business
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• 제7권10호
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• pp.149-159
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• 2020

Selecting an investment location is one of the most crucial decisions of investors as it has a great influence on the operation and development of the business in the future. At the same time, the attraction of localities will bring advantages for socio-economic development for the localities invested. Investors are interested in localities that have the potential to invest. The study focused on analyzing and testing the influence of place brand equity on the choice of investment locations of domestic investors through a regression analysis using 425 survey samples of investors in Phu Tho province, one of the northern industrial zones in Vietnam. Research results showed that 56.5% of investment decisions depended on factors from place brands. In addition, in the decision-making process for choosing investment locations, brand awareness factor had the greatest impact on investor's decisions, followed by brand image and brand personality, and finally brand confidence had the smallest impact. Therefore, in the coming time, in order to retain and attract domestic investors to choose Phu Tho as an investment and business destination, it is necessary to increase the value of place brand equity and implement solutions to promote place brands to investors.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2018년도 추계학술발표대회
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• pp.133-135
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• 2018

In these days, providing flexible and personalized network services subject to customers' requirements becomes an interesting issue for network service providers. Moreover, because each network service provider own finite network resources and infrastructure, dynamic network provisioning is essential to leverage the limited network resources efficiently and effectively for supporting personalized network services. Recently, as the population of mobile devices increases, the location-awareness becomes as important as the QoS-awareness to provision a network service dynamically. In this paper, we propose a framework for providing location-aware dynamic network services. This framework includes the web user interface for obtaining customers' requirements such as locations and QoS, the network generator for mapping the requested locations and network infrastructure, the network path calculator for selecting routes to meet the requested QoS and the network controller for deploying a prepared network services into SDN(Software-Defined Networking) enabled network infrastructure.