• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.1
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• pp.50-56
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• 2012

The Multi D.O.F spherical motor can drive rotating as well as tilting three degree of freedom with one motor. Existing three degree of freedom to drive with three motors that are connected by gears and belts, that will be too large size and big loss at gears and belts. So Reducing system size and improving efficient is using the Multi D.O.F spherical motor in three degree of freedom systems. For this reason, efficiency of Multi D.O.F spherical motor is one of the important performance indiccators. In this paper presented that how to improve the efficiency of the Multi D.O.F spherical motor. The fist of method is using the stator iron core's material with high permeability and resistivity for reducing the eddy current loss. However, it was the disadvatages of motor-making and economic. So author propose the resonable method of reducing the eddy current loss in the stator iron core. That is using the rotor with double-air gap.

• Journal of Family Resource Management and Policy Review
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• v.25 no.4
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• pp.87-99
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• 2021

The life of middle-aged one-person households is rising as one of the most important family policy issues in Korean society. In Japan, even in multi-person households, the issues of middle-aged sons and daughters living with their old parents have been a concern. Data are from the 13^th wave of the Korea Welfare Panel Study analyzing 482 middle-aged singe males regardless of their past marital status. The purpose of this study is to investigate the effects of human capital and social capital on the life satisfaction of middle-aged single persons by comparing one-person and multi-person households, respectively. Major results were as follows: First, the level of human capital of one-person households of middle aged males was lower than their counterparts in multi-person households. Second, the level of social capital in the group of divorced or widowed, nonhouseholder middle-aged males in multi-person households was lower than their counterparts in one-person households. Third, the effects of human capital and social capital on life satisfaction was significantly different by their marital status and household types in the group of middle-aged single males. Based on the results, policy implications on the community programs for middle-aged males including not only one-person households but also multi-person households were discussed.

• Journal of the Korean Society of Clothing and Textiles
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• v.33 no.4
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• pp.644-654
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• 2009

The purpose of this study is to analyze the characteristics of current fashion illustrations within the framework of Multi-space method. Multi-space means being piled up one moment & space on others, and being amassed in a scene. This method is related with Dadaism, Surrealism and Postmodernism, and also influences on the current fashion illustration. In this study, the types of Multi-space method could be classified into 4 types; Repetitive Time Mixture in Multi-space, Juxtaposed Time Mixture in Multi-space, Reiterated Space Mixture in Multi-space, Projected Space Mixture in Multi-space. The characteristics of Multi-space were analyzed and the results are as followed. The distinctive methods for Time Mixture in Multi-space are repetition and juxtaposition in a scene. Time Mixture in Multi-space can make the nonlinear narration and unreal illusory space in fashion illustrations more effectively. Reiterated Space Mixture in Multi-space can be related with the heterogeneous, surrealistic illusions in current fashion illustrations. Projected Space Mixture in Multi-space can be characterized into inter-penetration. It can derive spectators to mix the projected & transparent images in a scene for their own imaginary stories. The final imagination can be made differently according to the personal experiences of spectators.

• Journal of Institute of Control, Robotics and Systems
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• v.19 no.3
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• pp.209-218
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• 2013

Military surveillance systems with electro-optical sensors can be used to track a number of targets efficiently and reliably. In MTT (Multi-Target Tracking), joint events in which different tracks share the same measurements may occur. Measurement-to-track assignment are computationally challenging because of the number of operations increases exponentially with number of tracks and number of measurements. IHPDA (Integrated Highest Probability Data Association) based on a 2D-Assignment technique can find an optimal solution for measurement to track one-to-one assignments for complex environments. In this paper, LM-IHPDA (Linear Multi-Target IHPDA) which does not need to form all feasible joint events of association and thus the computational load is linear in the number of tracks and the number of measurements. Simulation studies illustrate the effectiveness of this approach in an infrared image environment.

• Transactions on Electrical and Electronic Materials
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• v.13 no.1
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• pp.27-30
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• 2012

This paper proposes a micro gas sensor for measuring $H_2S$ gas. This is based on a $SnO_2$-CuO multi-layer thin film. The sensor has a silicon diaphragm, micro heater, and sensing layers. The micro heater is embedded in the sensing layer in order to increase the temperature to an operating temperature. The $SnO_2$-CuO multi layer film is prepared by the alternating deposition method and thermal oxidation which uses an electron beam evaporator and a thermal furnace. To determine the effect of the number of layers, five sets of films are prepared, each with different number of layers. The sensitivities are measured by applying $H_2S$ gas. It has a concentration of 1 ppm at an operating temperature of $270^{\circ}C$. At the same total thickness, the sensitivity of the sensor with multi sensing layers was improved, compared to the sensor with one sensing layer. The sensitivity of the sensor with five layers to 1 ppm of $H_2S$ gas is approximately 68%. This is approximately 12% more than that of a sensor with one-layer.

• Journal of Korea Society of Industrial Information Systems
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• v.25 no.4
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• pp.39-47
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• 2020

We propose a multi-access points transmit power control algorithm in consideration of the channel estimation error and the multi-rate service. In the real communication systems, the channel estimation at the receiver side is imperfect due to limited number of pilot symbol usage. Furthermore, the multi-rate service is supported. We theoretically prove the uniqueness and the convergence of the proposed algorithm in multi-rate service environment. The proposed algorithm composes of one inner loop part and one outer loop part. Simulation results show that 1) the inner loop algorithm guarantees convergence of the transmit power level and the multi-rate service, 2) the outer loop algorithm compensates for the channel estimation error.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.16 no.9
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• pp.771-774
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• 2003

In this paper, the programming characteristics of the multi-bit devices based on SONOS structure are investigated. Our devices have been fabricated by 0.35 $\mu\textrm{m}$ complementary metal-oxide-semiconductor (CMOS) process with LOCOS isolation. In order to achieve the multi-bit operation per cell, charges must be locally frapped in the nitride layer above the channel near the source-drain junction. Programming method is selected by Channel Hot Electron (CUE) injection which is available for localized trap in nitride film. To demonstrate CHE injection, substrate current (Isub) and one-shot programming curve are investigated. The multi-bit operation which stores two-bit per cell is investigated. Also, Hot Hole(HH) injection for fast erasing is used. The fabricated SONOS devices have ultra-thinner gate dielectrics and then have lower programming voltage, simpler process and better scalability compared to any other multi-bit storage Flash memory. Our programming characteristics are shown to be the most promising for the multi-bit flash memory.

• Proceedings of the Korean Geotechical Society Conference
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• 2003.03a
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• pp.273-280
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• 2003

Tunneling in difficult geological conditions is often inevitable especially in urban areas. Ground improvement and reinforcement techniques are often required to guarantee safe tunnel excavations and/or to prevent damage to adjacent structures. The steel pipe-reinforced multi-step grouting method has been recently applied to tunnel sites in Korea as an auxiliary technique. In this study, the face stability with steel pipe-reinforced multi-step grouting was evaluated by simultaneously considering two factors: one is the effective stress acting on the tunnel face calculated by limit theorem and limit equilibrium method; the other is the seepage force obtained by means of numerical analysis. The study revealed that the influence of the steel pipe-reinforced multi-step grouting on the support pressure in dry condition is not significant while there is relatively a large amount of reduction in seepage forces by adopting the technique in saturated condition. The effect of the anisotropy of permeability on the seepage force acting on the tunnel face was also estimated by conducting the coupled analysis. It was found that a higher horizontal permeability compared with the vertical one causes reduction in the seepage force acting on the tunnel face.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.33 no.4
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• pp.69-78
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• 2010

Multi-criteria ABC inventory classification is one of the most widely employed techniques for efficient inventory control, and it considers more than one criterion for categorizing inventory items into groups of different importance. Recently, Ramanathan (2006) proposed a weighted linear optimization (WLO) model for the problem of multi-criteria ABC inventory classification. The WLO model generates a set of criteria weights for each item and assigns a normalized score to each item for ABC analysis. Although the WLO model is considered to have many advantages, it has a limitation that many items can share the same optimal efficiency score. This limitation can hinder a precise classification of inventory items. To overcome this deficiency, we propose a context-dependent DEA based method for multi-criteria ABC inventory classification problems. In the proposed model, items are first stratified into several efficiency levels, and then the relative attractiveness of each item is measured with respect to less efficient ones. Based on this attractiveness measure, items can be further discriminated in terms of their importance. By a comparative study between the proposed model and the WLO model, we argue that the proposed model can provide a more reasonable and accurate classification of inventory items.

• IEIE Transactions on Smart Processing and Computing
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• v.6 no.1
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• pp.27-38
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• 2017

Packet classification is one of the essential functionalities of Internet routers in providing quality of service. Since the arrival rate of input packets can be tens-of-millions per second, wire-speed packet classification has become one of the most challenging tasks. While traditional packet classification only reports a single matching result, new network applications require multiple matching results. Ternary content-addressable memory (TCAM) has been adopted to solve the multi-match classification problem due to its ability to perform fast parallel matching. However, TCAM has a fundamental issue: high power dissipation. Since TCAM is designed for a single match, the applicability of TCAM to multi-match classification is limited. In this paper, we propose a cost- and energy-efficient multi-match classification architecture that combines TCAM with a tuple space search algorithm. The proposed solution uses two small TCAM modules and requires a single-cycle TCAM lookup, two SRAM accesses, and several Bloom filter query cycles for multi-match classifications.