• Journal of KIISE:Computer Systems and Theory
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• v.31 no.10
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• pp.562-574
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• 2004

We address the problem of energy-optimal voltage scheduling for fixed-priority hard real-time systems. First, we prove that the problem is NP-hard. Then, we present a fully polynomial time approximation scheme (FPTAS) for the problem. for any $\varepsilon$>0, the proposed approximation scheme computes a voltage schedule whose energy consumption is at most (1+$\varepsilon$) times that of the optimal voltage schedule. Furthermore, the running time of the proposed approximation scheme is bounded by a polynomial function of the number of input jobs and 1/$\varepsilon$. Experimental results show that the approximation scheme finds more efficient voltage schedules faster than the best existing heuristic.

• Journal of IKEEE
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• v.5 no.2 s.9
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• pp.164-173
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• 2001

In this paper, we have designed and implemented a new hard embedded real-time system to satisfy hard real-time constraints in moving independently. Real-time kernel should be small size, fast and predictable. Because of the great variety of demands on real time scheduling, a real time kernel should also include a flexible and re-programmable task scheduling discipline. In this paper, we present that real-time applications should be split into small and simple parts with hard real-time constraints. To satisfy these properties, we designed real-time kernel and general kernel, that have their different properties. In real-time tasks, interrupt processing should be run. In general kernel, non real time tasks or general tasks are run. The efficiency of the proposed hard embedded real-time system is shown by comparison results for performance of the proposal real time kernel with both RT-Linux and QNX.

• Korean Institute of Interior Design Journal
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• v.19 no.3
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• pp.103-110
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• 2010

As ongoing construction of a new municipal government building leads to the destruction of the interior of the Kyungsung Municipal Government Building(currentlySeoul Metropolitan City Hall) despite its enormous historic value, this study aims to identify the unique features of spatial composition and interior design of the Kyungsung Municipal Government Building, which is widely known as a typical example of public architecture of the 1920s. The primary goal is to perform a systemic arrangement of its interior data and define the modern historic implications of its interior design, thereby laying the foundation for a compilation of the history of modern interior design. From a historical perspective, the Kyungsung Municipal Government Building-an explicit symbol of Japanese colonial supremacy-has served as the administrative hub of a hugecity for 19 years during the Japanese colonial rule and for 64 years following Korea's independence from Japan. From the perspective of architectural history, it also represents modern transitional buildingsin their shift from historicism into modernism, as manifested by its reasonable placement of interior space matching well with topographical form, easy access by citizens, open office space, and, excluding decoration, a simple and non-authoritarian exterior. Its interior design style follows Western historicist architecture, whereasits simple interior decoration embodies expressive characteristics of pragmatic simplicity. Such elements are notably found in the Grand Central Hall, the Municipal Head's Reception Room, and the Grand Conference Room.

• Journal of KIISE:Computer Systems and Theory
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• v.29 no.11
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• pp.601-610
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• 2002

Intra-task voltage scheduling (IntraVS), which adjusts the supply voltage within an individual task boundary, is an effective technique for developing low-power applications. In this paper, we propose a novel intra-task voltage scheduling algorithm for hard real-time applications based on average-case execution time. Unlike the conventional IntraVS algorithm where voltage scaling decisions are based on the worst-case execution cycles, tile proposed algorithm improves the energy efficiency by controlling the execution speed based on average-case execution cycles while meeting the real-time constraints. The experimental results using an MPEG-4 decoder program show that the proposed algorithm reduces the energy consumption by up to 34% over conventional IntraVS algorithm.

• KIEAE Journal
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• v.10 no.1
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• pp.91-96
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• 2010

Incheon Free Economic Zone's Songdo Area is a newly constructed city built on land reclaimed from the seaside and the surrounding area. Yeongjong Area is made after Land reclamation between Yeongjong Island and Yongyou Island began in November 1992. The first phase linking these islands to create the Incheon International Airport (phase 1) and the Airport Town Square community was finished in March 2001. However, if we take a look at the overall status of the project as it is carried on at present, it is hard to deny that the project is trapped inside the same legal restrictions as are all other existing cities, which permits Songdo Area and Yeongjong Area to meet only very minimum standards. This study intends to analyze and assess the Incheon Free Economic Zone's Songdo Area and Yeongjong Area of environmentally friendly construction and to rate its current development status, exposing any problems and offering alternative solutions. In this paper, the current state of constructions in Songdo Area and Yeongjong Area were reviewed. Then a quantitative analysis and assessment for the Songdo Area and Yeongjong Area constructions of apartments, complex buildings, office buildings, school facilities, store and hotel facilities were conducted by using green building certification criteria. Finally the synthetic results of environmental performance evaluation for Incheon Free Economic Zone's Songdo Area and Yeongjong Area constructions and follow-up suggestions were described.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2005.05a
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• pp.106-109
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• 2005

The awareness of ecological friendliness has been emerging in the recent years, and the application to housing is quite notable. The purpose of this study was to examine multi-family housing that has recently developed with the idea of ecological friendliness, and to investigate the residents' attitudes toward and their preferences for the features. The research utilized in-depth interviews and site visits, and seven residents in the studied housing developments participated in the study. The analytical tool used in the interview was reviewed by a panel of professionals and included five aspects of ecologically friendliness: residential comfort, energy saving, open housing, storage, and safety and security. The respondents pointed out that south-facing housing in relation to residential comfort was most favorable. With regard to energy-saving, water-saving features and dehydrator of food waste were most needed features. As for open housing-related features, flexibility in spatial configuration was necessary, and efficient storage was regarded as important. Also, the respondents mentioned the preference for flooring preventing slippery in bathroom for the safety of family member.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.5
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• pp.1183-1188
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• 2011

The novel metal position detection method is proposed where conventional techniques, in high temperature, moisture and particle environment, are not able to be applied. It is known that electronic devices, utilizing microwave, ultrasonic or optical technique, are hard to apply for sensing application where temperature is exceeding above 300 degree centigrade. Metal position detection technique, which was consisted with passive elements facing hot sensing surface, utilizing electromagnetic wave was investigated, and the metal detection sensitivity was measured by varying sensor frequency and sensing distance. Measurement result in laboratory test set-up showed position measurement resolution up to 1mm, when distance between two sensing elements were 500mm, and possibility to measure position of hot metal sheet having very high surface temperature.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.1
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• pp.191-197
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• 2007

Vision system is an object recognition system analyzing image information captured through camera. Vision system can be applied to various fields, and vehicle recognition is ole of them. There have been many proposals about algorithm of vehicle recognition. But have complex calculation processing. So they need long processing time and sometimes they make problems. In this research we suggested vehicle type recognition system using vision bpx based on embedded platform. As a result of testing this system achieves 100% rate of recognition at the optimal condition. But when condition is changed by lighting, noise and angle, rate of recognition is decreased as pattern score is lowered and recognition speed is slowed.

• Bulletin of the Korean Chemical Society
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• v.17 no.8
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• pp.735-744
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• 1996

We present results of molecular dynamic (MD) simulations for the thermodynamic and structural properties of liquid n-alkanes, from n-butane to n-heptadecane, using three different models Ⅰ-Ⅲ. Two of the three classes of models are collapsed atomic models while the third class is an atomistically detailed model. Model Ⅰ is the original Ryckaert and Bellemans' collapsed atomic model [Discuss. Faraday Soc. 1978, 66, 95] and model Ⅱ is the expanded collapsed model which includes C-C bond stretching and C-C-C bond angle bending potentials in addition to Lennard-Jones and torsional potentials of model Ⅰ. In model Ⅲ all the carbon and hydrogen atoms in the monomeric units are represented explicitly for the alkane molecules. Excellent agreement of the results of our MD simulations of model Ⅰ for n-butane with those of Edberg et al.[J. Chem. Phys. 1986, 84, 6933], who used a different algorithm confirms the validity of our algorithms for MD simulations of model Ⅱ for 14 liquid n-alkanes and of models Ⅰ and Ⅲ for liquid n-butane, n-decane, and n-heptadecane. The thermodynamic and structural properties of models Ⅰ and Ⅱ are very similar to each other and the thermodynamic properties of model Ⅲ for the three n-alkanes are not much different from those of models Ⅰ and Ⅱ. However, the structural properties of model Ⅲ are very different from those of models Ⅰ and Ⅱ as observed by comparing the radial distribution functions, the average end-to-end distances and the root-mean-squared radii of gyrations.

• Bulletin of the Korean Chemical Society
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• v.20 no.8
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• pp.897-904
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• 1999

We have presented the thermodynamic, structural and dynamic properties of liquid pentane isomers - normal pentane, isopentane, and neopentane - using an expanded collapsed atomic model. The thermodynamic properties show that the intermolecular interactions become weaker as the molecular shape becomes more nearly spherical and the surface area decreases with branching. The structural properties are well predicted from the site-site radial, the average end-to-end distance, and the root-mean-squared radius of gyration distribution func-tions. The dynamic properties are obtained from the time correlation functions - the mean square displacement (MSD), the velocity auto-correlation (VAC), the cosine (CAC), the stress (SAC), the pressure (PAC), and the heat flux auto-correlation (HFAC) functions - of liquid pentane isomers. Two self-diffusion coefficients of liquid pentane isomers calculated from the MSD's via the Einstein equation and the VAC's via the Green-Kubo relation show the same trend but do not coincide with the branching effect on self-diffusion. The rotational re-laxation time of liquid pentane isomers obtained from the CAC's decreases monotonously as branching increases. Two kinds of viscosities of liquid pentane isomers calculated from the SAC and PAC functions via the Green-Kubo relation have the same trend compared with the experimental results. The thermal conductivity calculated from the HFAC increases as branching increases.