• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.11a
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• pp.93-96
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• 1996

We developed three dimensional Monte carlo ion implantation simulator which simulate distributions of impurities under the ion implantation on the tilted multi-layered layer. Our simulation reveals three dimensional shadow effect and sidewall scattering effect due to the geometrical shapes. For the evaluation of the developed three dimensional Monte carlo ion implantation simulator, calculations with 100,000 ions have been performed for the island and hole structures with a thin oxide of 100$\AA$ and nitride of 2000$\AA$. The simulation results showed that the distribution of ion decreases near the conner of the hole structure covered with a nitride layer and increases near the conner for the island structure open to oxide. Moreover, three dimensional distributions of ions were obtained with varying incident energy, tilt and rotation angle, mask depth and three-dimensional structure geometry.

• Journal of the Korea Society for Simulation
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• v.7 no.2
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• pp.63-78
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• 1998

The hierarchical cell structure consists of the macrocell and microcells to increase the system capacity and to achieve broad coverage. The hierarchical cell structure provides services for users in different mobility. In this paper, an analytical queueing model in mobile networks is proposed for the performance evaluation of the hierarchical cell structure. The model for networks with the multiple levels can simplify multi-dimensional ones into one-dimensional queueing model. The computational advantage will be growing as the layers are constructed in multiple levels. The computer simulation is provided for validating the proposed analytical model.

• Bulletin of the Korean Chemical Society
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• v.13 no.5
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• pp.538-541
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• 1992

An approximate scheme for evaluating total reaction probability is proposed. Semiclassical boundary conditions are imposed well before the asymptotic region in the reactant and product channels to calculate the Green's function and its derivatives. Propagations are confined to a limited regime near the activated complex. Calculations are made for one dimensional Eckart barrier model of H + $H_2$ reaction. Implications of the procedure in multi-dimensional systems are discussed.

• Journal of the Korean Operations Research and Management Science Society
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• v.33 no.2
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• pp.45-73
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• 2008

Quality has long been considered as an important factor in creating competitive advantage, and researches on quality have not been limited to off-line products but actively extended to e-services and information goods. However, given the nature of multi-dimensional aspect of quality, the systematic study on the quality of online service is still in its early stage. Especially, studies on the quality of ASP services have been rare in academic and professional journals despite the growth of ASP industry in its size and the rapid expansion in the range of application. In this paper we clarified the multi-dimensional quality aspects of the ASP service using a Garvin's framework (1984) which encompasses the service aspects of Products, and developed a measurement model for ASP service qualify. Then we empirically tested the effects of ASP service quality on user satisfaction and perceived firm performance using the data from 240 Korean small firms with less than 50 employees that had experienced the ASP service. Our results show that there are positive relationships among ASP service quality and personal performance, user satisfaction and perceived firm performance, and that product and service-related aspects of ASP service exert differential effects on performance measures so that the product-related aspects of the ASP service such as performance, features, reliability and conformance are considered to be more important in evaluating benefits from ASP services. Contrary to the approaches In literature where only the quality of online services is evaluated, our results emphasize the importance of differentiating Product and service-related aspects of ASP service and provide a basis for more comprehensive evaluation of ASP service quality.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2000.11a
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• pp.117-120
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• 2000

When analyzing the scatting problem of multi-layered structures using closed-form Green's function, one of the main difficulties is that the numerical integrations for the evaluation of diagonal matrix elements converge slowly and are not so stable. Accordingly, even when the integration for the singularity of type e$\^$-jkr//${\gamma}$/, corresponding to the source dipole itself, is performed using such a mathod, this difficulty persists in the integration corresponding to the finite number of complex images. In order to resolve this difficulty, a new technique based upon the Gaussian quadrature in polar coordinates for the evaluation of the two-dimensional generalized exponential integral is presented. Stability of the algorithm and convergence is discussed. Performance is demonstrated for the example of a microstrip patch antenna.

• Journal of Conservation Science
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• v.22
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• pp.31-42
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• 2008

A stone cultural heritage often lacks design drawing and detailed geometric informations, thus it becomes more difficult to conservation and restoration. Even though there is active database of detail shape information and numerical measurement for stone monuments, most of the data is in hard-to-utilize two-dimensional images. The new technology developed to overcome this problem is three-dimensional image scanning system. The multi-storied stone pagoda of the Daewonsa temple was analysed with 3D scanning image data then survey map with orientation displacement was evaluated. The difference of each side became apparent with the members of the stone properties was measured, also horizontal and vertical displacement occurred. Horizontal displacement occurred in increasing severity from left to right and from body section to upper part. The 8th roof stones are leaning toward northwest direction due to lateral displacement. The evaluation and measurement of displacement could cause a little errors due to the characteristics uneven surface of stone monuments, computer program and mistakes from the researcher. In future, more precise measurement and stability studies should be done to suggest that accurate data for conservation and understanding of damage condition can be provided.

• The KIPS Transactions:PartD
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• v.10D no.2
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• pp.195-210
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• 2003

In this paper, we propose an enhanced concurrency control algorithm that maximizes the concurrency of multi-dimensional index structures. The factors that deteriorate the concurrency of index structures are node splits and minimum bounding region (MBR) updates in multi-dimensional index structures. The proposed concurrency control algorithm introduces PLC(Partial Lock Coupling) technique to avoid lock coupling during MBR updates. Also, a new MBR update method that allows searchers to access nodes where MBR updates are being performed is proposed. To reduce the performance degradation by node splits the proposed algorithm holds exclusive latches not during whole split time but only during physical node split time that occupies the small part of a whole split process. For performance evaluation, we implement the proposed concurrency control algorithm and one of the existing link technique-based algorithms on MIDAS-3 that is a storage system of a BADA-4 DBMS. We show through various experiments that our proposed algorithm outperforms the existing algorithm in terms of throughput and response time. Also, we propose a recovery protocol for our proposed concurrency control algorithm. The recovery protocol is designed to assure high concurrency and fast recovery.

• Journal of the Korean Applied Science and Technology
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• v.35 no.4
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• pp.1260-1268
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• 2018

To improve fuel performance and specific characteristics of long storage and moving through fuel systems additives should be added in kerosene type aviation turbine fuel (AVTUR) such as antioxidant, fuel system icing inhibitor (FSII), electric conductivity improvers and so on. The dosage of additives has to be analyzed qualitatively and quantitatively due to inspect the quality of abnormal fuel and distinguish other petroleum products. Multi-dimensional GC-MS (MDGC-MS) with Deans switching technique are applied the determination of antioxidant and FSII, which are added with AVTUR containing complex mixture of hydrocarbons. Antioxidant and FSII in the range of 2.5-20 mg/L was quantitatively and qualitatively analyzed using MDGC-MS and the detection limit was about twice as low as that of the 1-dimensional GC-MS results. The method in this study has been higher peak resolution compared with GC-MS and could be simultaneously analyzed different two additives without sample pre-treatment.

• Journal of the Korean Society of Safety
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• v.18 no.4
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• pp.98-104
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• 2003

Various nondestructive evaluation (NDE) techniques have been studied to locate steel rebars of dowel, and to detect invisible damage such as voids and cracks inside concrete and debonding between rebars and concrete caused by corrosions and earthquakes. In this study, the aurhors developed 3-dimensional (3D) electromagnetic (EM) imaging technology to detect such damage and to identify exact location of steel rebars of dowel. The authors have developed sub-surface two-dimensional (2D) imaging technique using tomographic antenna array in previous works. In this study, extending the earlier analytical and experimental works on 2D image reconstruction, a 3D microwave imaging system using tomographic antenna array was developed, and multi-frequency technique was applied to improve quality of the reconstructed image and to reduce background noises. This paper presents the analytical expressions of numerical focusing procedures for 3D image reconstruction and numerical simulation to study the resolution of the system and the effectiveness of multi-frequency technique. Also, the design of 4?4 antenna array with switching devices is introduced as a preliminary study for the final design of whole array.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.06a
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• pp.1155-1160
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• 2005

In order to evaluate the safety of navigation at sea and the safety of mooring ship on berthing, it is necessary that the wave and wind induced ship dynamic motion should be measured in real time domain for the validity of theoretical evaluation method such as sea-keeping performance and safety of mooring. In this paper, the basic design of sensors is discussed and some system configurations were shown. The developed system mainly consists of 4 kinds of sensors such as three dimensional accelerator, two dimensional tilt sensor, two displacement sensors and azimuth sensor. Using the this measuring system, it can be obtained the 6 degrees of freedom of ship dynamic motions at sea and on berthing such as rolling, pitching, yawing, sway, heave, surge under the external forces.