• Journal of Korea Multimedia Society
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• v.11 no.4
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• pp.415-422
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• 2008

With the increasing use of XML, considerable research is being conducted on the XML document management systems for more efficient storage and searching of XML documents. Depending on the base systems, these researches can be classified into object-oriented DBMS (OODBMS) and relational DBMS (RDBMS). OODBMS-based systems are better suited to reflect the structure of XML-documents than RDBMS based ones. However, using an XML parser to map the contents of documents to relational tables is a better way to construct a stable and effective XML document management system. The proposed X-Binder system uses an RDBMS-based inverted index; this guarantees high searching speed but wastes considerable storage space. To avoid this, the proposed system incorporates a path combining module agent that combines paths with sibling relations, and stores them in a single row. Performance evaluation revealed that the proposed system reduces storage wastage and search time.

• Korean Journal of Remote Sensing
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• v.34 no.2_1
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• pp.301-306
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• 2018

Urbanization causes urban floods and urban heat island in the summer, so it is necessary to understanding the changes of the thermal environment through urban climate and energy balance. This can be explained by the energy balance, but in urban areas, unlike the typical energy balance, the storage heat flux saved in the building or artificial land cover should be considered. Since the environment of each city is different, there is a difficulty in applying the method of retrieving the storage heat flux of the previous research. Especially, most of the previous studies are focused on the overseas cities, so it is necessary to study the storage heat retrieval suitable for various land cover and building characteristics of the urban areas in Korea. Therefore, the object of this study, it is to derive the regression formula which can quantitatively retrieve the storage heat using the data of the area where various surface types exist. To this end, nonlinear regression analysis was performed using net radiation and surface temperature data as independent variables and flux tower based storage heat estimates as dependent variables. The retrieved regression coefficients were applied to each independent variable to derive the storage heat retrieval regression formula. As a result of time series analysis with flux tower based storage heat estimates, it was well simulated high peak at day time and the value at night. Moreover storage heat retrieved in this study was possible continuous retrieval than flux tower based storage heat estimates. As a result of scatter plot analysis, accuracy of retrieved storage heat was found to be significant at $50.14Wm^{-2}$ and bias $-0.94Wm^{-2}$.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1093-1098
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• 2003

In this paper, a practical methodology of hand-manipulator motion coordination for indoor service robot is introduced. This paper describes the procedures of opening door performed by service robot as a noticeable example of motion coordination. This paper presents well-structured framework for hand-manipulator motion coordination, which includes intelligent sensor data interpretation, object shape estimation, optimal grasping, on-line motion planning and behavior-based task execution. This proposed approach is focused on how to integrate the respective functions in harmony and enable the robot to complete its operation under the limitation of usable resources. As a practical example of implementation, the successful experimental results in opening door whose geometric parameters are unknown beforehand are provided.

• Journal of Korea Multimedia Society
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• v.20 no.8
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• pp.1312-1320
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• 2017

Recently, vector map data is developed and used in many domains widely. In the most cases, vector map data contains confidential information which must be kept away from unauthorized users. Moreover, the production process of vector maps is considerably complex and consumes a lot of money and human resources. Therefore, the secured storage and transmission are necessary to prevent the illegal copying and distribution from hacker. This paper presents a selective encryption algorithm using geometric objects in frequency domain for vector map data. In the proposed algorithm, polyline and polygon data in vector map is the target of the selective encryption process. Experimental results verified that proposed algorithm is effectively and adaptive the requirements of security.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.9
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• pp.26-32
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• 2011

The object of this paper is to optimize the battery system for supplying stably power in separate house in which a PV-wind hybrid power generation system is applied. In a power system to be used in a stand alone, it is very important to build optimize the electrical storage system and to utilize it for supplying stably output voltage when there is a shortage of the power generation capacity or there is no sunshine, or when power is to be supplied with a load. This paper provides an optimized method to evaluate capacity of battery by analyzing advantages and disadvantages of the existing battery evaluating method being used in each company for supplying stably power in separate house utilizing the new renewable energy such as a light of the sun.

• Journal of the Korean Society of Safety
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• v.30 no.3
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• pp.93-99
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• 2015

Economic burden of work-related musculoskeletal disorder(WMDs) is increasing. Known causes of WMDs include improper posture, repetition, load, and temperature of workplace. Among them, improper postures play an important role. A smart sensor called SensorTag is employed to estimate the trunk postures including flexion-extension, lateral bend, and the trunk rotational speeds. Measuring gravitational acceleration vector in the smart sensor along the tri-orthogonal axes offers an orientation of the object with the smart sensor attached to. The smart sensor is light in weight and has small form factor, making it an ideal wearable sensor for body posture measurement. Measured data from the smart senor is wirelessly transferred for analysis to a smartphone which has enough computing power, data storage and internet-connectivity, removing need for additional hardware for data post-processing. Based on the estimated body postures, WMDs risks can be conviently gauged by using existing WMDs risk assesment methods such as OWAS, RULA, REBA, etc.

• Proceedings of the Korea Information Processing Society Conference
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• 2017.11a
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• pp.6-7
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• 2017

디지털 데이터의 폭발적 증가와 형태의 다양화는 최근 비정형 대규모 저장 플랫폼의 급격한 확산을 이끌고 있다. 이러한 비정형 데이터 저장 시스템은 전통적인 파일시스템과 데이터를 저장 및 처리하는 방식이 상이하여 높은 성능을 위해서는 기존 하위 시스템의 최적화가 필요하다. 이에 본 논문에서는 최근 급부상하고 있는 분산 오브젝트 스토어인 Ceph을 중심으로 오브젝트 스토어의 스토리지 접근 패턴을 분석하는 연구를 수행한다. 본 연구는 상위 계층의 접근패턴을 구체적으로 이해함으로써 차세대 데이터 플랫폼을 효율적으로 지원할 수 있는 스토리지 시스템을 개발하는 데에 기여한다고 하겠다.

• Journal of Satellite, Information and Communications
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• v.7 no.3
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• pp.140-144
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• 2012

The classic method of recording and retrieving of images for video monitoring was very inefficient since the system required huge storage capacity. It's because it stored images without separating background and monitored objects. The recording and retrieval method of images for the video monitoring system we proposed in this paper makes it possible to retrieve images easily by using database by the hour and the place. Hence, it retrieve images much more efficiently than the existing method.

• Proceedings of the Korea Information Processing Society Conference
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• 2007.05a
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• pp.955-957
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• 2007

본 연구에서는 모바일 기기의 중요한 성능 요소 중 하나인 스토리지에 초점을 맞추고 멀티미디어 콘텐츠 재생 성능 향상을 위한 시스템을 제안한다. 이를 위해 모바일 기기에서 사용 가능한 여러 스토리지 기술 중 최신 기술인 객체기반 IP 스토리지 시스템을 기반으로 모바일 단말 측에 캐시 및 선반입(prefech) 기능을 적용하여 네트워크를 사용하는 입출력으로 인한 재생 시스템의 성능저하를 보완한다.

• Journal of Communications and Networks
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• v.12 no.2
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• pp.181-190
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• 2010

A multitude of overlay network designs for resilient routing, multicasting, quality of service, content distribution, storage, and object location have been proposed. Overlay networks offer several attractive features, including ease of deployment, flexibility, adaptivity, and an infrastructure for collaboration among hosts. In this paper, we explore cooperation among co-existing, possibly heterogeneous, overlay networks. We discuss a spectrum of cooperative forwarding and information sharing services, and investigate the associated scalability, heterogeneity, and security problems. Motivated by these services, we design Synergy, a utility-based overlay internetworking architecture that fosters overlay cooperation. Our architecture promotes fair peering relationships to achieve synergism. Results from Internet experiments with cooperative forwarding overlays indicate that our Synergy prototype improves delay, throughput, and loss performance, while maintaining the autonomy and heterogeneity of individual overlay networks.