• Journal of the Korean Society of Propulsion Engineers
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• v.5 no.1
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• pp.18-25
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• 2001

The results of systematic numerical experiments of secondary gas injection thrust vector control are presented. The effects of secondary injection system such as injection location and nozzle divergent cone angle onto the overall performance parameters such as thrust ratio, specific impulse ratio and axial thrust augmentation, are investigated. Complex nozzle exhaust flows induced by the secondary jet penetration is numerically analyzed by solving unsteady three-dimensional Reynolds-averaged Navier-Stokes equations with Baldwin-Lomax turbulence model for closure. Numerical simulations compared with the experiments of secondary air injection into the rocket nozzle of $9.6^{\cire}$ divergent half angle showed good agreement. The results obtained in terms of overall performance parameters showed that locating the secondary injection orifice further downstream of primary nozzle ensures the prevention of occurrence of reflected shock wave, therefore is suitable for efficient and stable thrust vectoring over a wide range of use.

• Journal of the Korean Electrochemical Society
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• v.14 no.1
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• pp.33-37
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• 2011

$Li_4Ti_5O_{12}$ has been considered a potential material for high power lithium batteries. Since $Li_4Ti_5O_{12}$ is however an insulator having a broad band gap, various methods have been employed to improve the conductivity. In this study, we have investigated the change of fine structure and electronic structure by Cr doping using X-ray absorption spectroscopy and First Principle Calculation. Doping with Cr, we could obtain an enhanced electronic conductivity by locating the Fermi level at the center position of Cr d-band and identify the change of XANES pre-edge and white line peak due to the increase of electron density of Ti d-band.

• Journal of the Economic Geographical Society of Korea
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• v.4 no.1
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• pp.1-18
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• 2001

Some spread-effects and their dynamics accruing to regional community from the new location of large firms would be an interesting theme in economic geography On the assumption that all firms not only should. have cooperative relations with their regional communities but also try to realize such cooperations in case of locating their facilities, some rationale for their philanthropic activities will be discussed in this paper. The focus of this paper is on the community contributions or philanthropy which are executed as the non-profit motivated activities of firms. Why and how should firms respond to the growing requirements of their communities, and what type of philanthropic activities could be good for their social behavioral contexts are the questions to be solved in this study. It is possible to get some guidelines of a firm's philanthropy through the comparisons on the practices in the three largest firm.5: Kodak. Dupont, and POSCO.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.2
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• pp.83-92
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• 2018

Using ground moving target indicators equipped with synthetic aperture radars for locating moving targets within a wide background clutter in a short time is an excellent method for monitoring traffic. Although the displaced phase center antenna (DPCA) technique and along track interferometry (ATI) are real time methods with low computational complexity, they are essential for reducing cases of false alarm that can result in poor performance. In this paper, we propose two detection methods using DPCA and ATI-the parallel fusion method and serial fusion method. Simulation results demonstrate that the proposed detection methods are characterized by low probability of false alarm along with good performance. In particular, the serial fusion method possesses high detection probability along with low probability of false alarm (1/5th of the false alarm probability of the DPCA technique).

• Journal of the Korean Institute of Gas
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• v.23 no.5
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• pp.35-43
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• 2019

The safety of industrial valves, which are the core parts of plant facilities, are managed by manpower and there are difficulties because of side area for inspection and limited accessibility due to the nature of facilities. The industrial valves used in plant facilities cause problems such as interrupted production; a loss of life due to leak or explosion of poisonous material and flammable gases, and difficulty in locating accident positions in the event of leakage or failure. Therefore, safety management and control systems based on IoT technology are needed. This study is about the development of risk factor prediction technique among the safety management of industrial valves through IoT- based wireless communication and the development of actuator control system. We have developed IoT-based industrial valve safety management techniques to prevent accidents caused by main risk factors by conducting an analysis of the structural characteristics of valves and an analysis of the causes of main risk factors through review of failure data and literature and an analysis of accident scenarios.

• Journal of the Korean Institute of Landscape Architecture
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• v.29 no.1
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• pp.113-123
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• 2001

The purpose of this study is to help out the settlement of the Green Map in Korea, and to suggest how to map, and help community people and environmental planner systematically take care of their own towns. This study is also to introduce the green mapping and its usefulness, based on the Green Map Movement, which originated from Net York City and has been expanding through the World. Environmental elements shown on the Green map vary between countries and for the Seocho-Gu Green Map, we have decided to indicate the places that we are proud of, and dishonored of. Especially, this paper is focused on finding the hidden environmental resources in our daily lives. Seocho-Gu, one of 25 self-governmental resources. Since the citizens and government officials are open-minded in their environments, it is a suitable area to start the first Green Map in Korea. As a method of locating the environmental resources, the "Foot Sensing Method" by which residents directly research, is the main difference from typical maps by the "Remote Sensing" which focused on the variety participation of the residents such as questionnaires, investigation with youth volunteers, users interviews which may be more meaningful than the Green Map itself. The purpose of application plan is to preserve the environmental resources through the smooth feedback with the residents. Thus, it must be acted as a opening window linking them with the local circumstances. In line with this, this study proposed the trial-version Web Green Map and Green tour plan. Recently, a need for an environmental map has been reflected in the environmental policies of Seoul Metropolitan City, and it is in place now. If environmental experts of different disciplines use the Green Map for landscape architecture, design, and city planning, it will help them make a better understanding of the needs of the community and to practice the user-centered design. Eventually, the Seocho-Gu Green Map will help its residents, tourists, government, and environmental planners continue establishing the healthy city environments. It is expected that the green map will be employed as a useful method for establishing healthy city and town through right way of use and contents.of use and contents.

• Journal of the Korean Institute of Landscape Architecture
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• v.25 no.2
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• pp.104.1-104.1
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• 1997

The purpose of this study is to grasp the characteristics of user''''s response to perceived safety and visual preferences for outdoor green spaces by the types of campus layouts. This research was investigated by color slide ratings and questionnaire survey to the students who are majoring in Landscape architecture in three universities locating at Taegu area. Two research sites have similarities in many ways but have differences in campus land form and design type such as ''''Closed'''' and ''''Open'''' types. Major results were summarised as follows ; 1. As a result of the slide test, the high degree of visual preference was shown in the campus that is ''''Closed'''' type. However the degree of perceived safety was lower than that of in Youngnam Univ. campus. 2. According to the result of the comparative analysis between user''''s perceived safety and visual preferences in each campus, the degree of perceived safety at ''''Closed'''' type was lower than that of ''''Open'''' type, but the degree of visual satisfactioni was higher at ''''Closed'''' type. 3. The factors affecting visual preference in campus were shown as density of wood, land form, and diverse type of the spaces. On the other hand, the factors affecting perceived safety were ''''enclosed space by wood'''' at the day time, and ''''the condition of lighting'''' at night. 4. Regarding gender differences in sensation of each space variables, female users showed higher satisfactio on the scenic beauty. 5. Regression analysis showed that general satisfation was determined by the variables such as ''''arrangement'''', familiarity'''', ''''cleanness'''', and ''''closed feeling'''', in Kyungbook Univ. And in Youngnam Univ. , the variables were ''''texture'''', ''''perceived beauty'''', ''''cleanness'''', and ''''complexity'''' respectively. 6. In conclusion, campus users wanted the outdoor spaces that have various land form and somewhat ''''open-closed'''' mixture type, which has a good ''''Edge Effect'''' to satisfy both aspects in safety and visual preferneces.

• Journal of the Korean Institute of Landscape Architecture
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• v.25 no.2
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• pp.104-116
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• 1997

The purpose of this study is to grasp the characteristics of user's response to perceived safety and visual preferences for outdoor green spaces by the types of campus layouts. This research was investigated by color slide ratings and questionnaire survey to the students who are majoring in Landscape architecture in three universities locating at Taegu area. Two research sites have similarities in many ways but have differences in campus land form and design type such as 'Closed' and 'Open' types. Major results were summarised as follows ; 1. As a result of the slide test, the high degree of visual preference was shown in the campus that is 'Closed' type. However the degree of perceived safety was lower than that of in Youngnam Univ. campus. 2. According to the result of the comparative analysis between user's perceived safety and visual preferences in each campus, the degree of perceived safety at 'Closed' type was lower than that of 'Open' type, but the degree of visual satisfactioni was higher at 'Closed' type. 3. The factors affecting visual preference in campus were shown as density of wood, land form, and diverse type of the spaces. On the other hand, the factors affecting perceived safety were 'enclosed space by wood' at the day time, and 'the condition of lighting' at night. 4. Regarding gender differences in sensation of each space variables, female users showed higher satisfactio on the scenic beauty. 5. Regression analysis showed that general satisfation was determined by the variables such as 'arrangement', familiarity', 'cleanness', and 'closed feeling', in Kyungbook Univ. And in Youngnam Univ. , the variables were 'texture', 'perceived beauty', 'cleanness', and 'complexity' respectively. 6. In conclusion, campus users wanted the outdoor spaces that have various land form and somewhat 'open-closed' mixture type, which has a good 'Edge Effect' to satisfy both aspects in safety and visual preferneces.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.508-511
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• 2005

In the near future various new services will be created by using ubiquitous computing and ubiquitous network. Especially u-LBS(Ubiquitous Location Based Services) is recognized as one of the most important services. U-LBS is based on the data created by recognizing objects including both human and matters at any time and anywhere. Many researches related with object locating method by using RF are in the process of studying However there are few researches on the location of objects. In this paper we propose the recognition method of the location of objects by using RF and USN technology. In detail, the strength of RF signal is used to recognize the location of objects. Also we discuss about the future work to enhance the recognition rate of location by using a number of conditions including the weather, temperature etc. And Genetic Algorithm is used to get the optimal parameters with which we can get the more exact recognition rate of location.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.2
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• pp.521-533
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• 2010

The OSGi framework is a java-based service platform that can be remotely managed, providing an application life cycle management model, a service registry and an execution environment. Based on the framework, various OSGi layers, APIs, and services have been defined. A bundle is an application that can be executed in the OSGi framework, deployed through a bundle repository. Usually, bundles in the repository are accessible via a designated web page. Unfortunately, the current bundle repositories do not provide any kind of group access services and dynamic bundle installation and deployment. In this paper, we describe a WebDAV-Based OSGi bundle repository named WOBR, which supports effective group-based accesses. WOBR is composed of a WOBR bundle repository, a management bundle and an access bundle that interact with the bundle repository. The management bundle is for configuration of the WOBR bundle repository, managing group access facility to the repository. The access bundle provides access to the repository and search mechanism for the bundles. Additionally, it provides the life cycle management of the installed bundles on the local environment.