• Journal of the Korean Data and Information Science Society
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• v.17 no.1
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• pp.141-147
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• 2006

BOK-X12-ARIMA has been developed by the Bank of Korea in order to accomodate special features such as lunar effect, labor day and election effect which are intrinsic in Korean seasonal time series. Irregular component resulting from BOK-X12-ARIMA is usually treated as white noise time series. If this shows dependency structure, it may be advisable to incorporate dependency in irregular component into prediction. This article illustrates how to refine point forecast using dependency structure in irregular component.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.10a
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• pp.365-369
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• 2002

This paper introduces that the machine tools's feed system optimizes by modeling for simulation and adjusting drive control parameter. The first method is frequency response of speed loop with design parameter by use of MATLAB application, in order that other axis can do equal to bandwidth. The second meted uses various sensor for analyzing machine tools's structure and adjustes jirk limitter.

• YAKHAK HOEJI
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• v.25 no.4
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• pp.175-179
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• 1981

Rheological studies on the gelatin hydrogels were carried out by rheometer. In the temperature range of $32^{\circ}~90{\circ}C$, the viscosities of the gelatin hydrogels were measured. In order to observe the formation of gel structure, the stress-relaxation tests of the creep-curves were investigated. The structure of viscoelastic substance could be considered of a three dimensional crosslinked matrix. As the result viscoelastic coefficients were obtained by Maxwell element, which are correspond to the network structure. From the relationship between the stress-relaxation time and temperature, activation energy correspond to breaking the formation of gels was calculated to be 13.91kcal/mole.

• Journal of the Korean Chemical Society
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• v.14 no.4
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• pp.309-319
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• 1970

Composition of Acid Clay, the raw material for activated clay manufacturing, was investigated to develop useful data in deciding activation condition. Speculations on components and structure of activated clay were also made in order to see how included components of raw materials change during activation process. And a study was made on relations between structure of activated its adsorptivity. For this research, theremogravimetric analysis, X-ray differaction analysis and calculation of adsorptive index were carried out.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.6
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• pp.625-632
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• 1992

This paper presents a new dc-motor position control approached by Variable Structure System. In order to eliminate a steady-state position error, we propose a switching function composed of position error, velocity, and current ripple. The switching function has an advantage compared to other ones. To determine the control signal voltage, we use a fuzzy logic method. The simulation results show expected performances.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.358-360
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• 2002

In order to find horizontal and vertical precipitation structure in Korean peninsula, we use ground-based radar, and Automatic Weather Station (AWS) data. Radar data was selected for rain events in the Pusan and Jindo in Korea, during the spring and summer season of 2002. AWS point gauge measurements are analyzed as part of spatial structure of precipitation. TRMM/PR and ground-based radar is used vertical correlation. The results showed, as expected that the correlation decreased rapidly with distance.

• Journal of Auto-vehicle Safety Association
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• v.13 no.4
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• pp.26-32
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• 2021

This study is intended to augment the Roof strength test being evaluated by IIHS (Insurance Institute for Highway Safety). In order to find solutions for increasing Roof Crashworthiness Evaluation SWR (Strengthto-weight ratio). This study introduces that Integrated Connection Structure Between Center Pillar and Roof Center Rail is proposed as a critical solution.

• IE interfaces
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• v.13 no.3
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• pp.396-404
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• 2000

For most order-based production, it is important to meet urgent orders from important customers while maintaining high on-time delivery rate for successful supply chain management. In this paper, we propose an approach and a structure of planning system to implement Capable-To-Promise which promises the delivery time to the received order. We suggest and compare a few alternative order receiving policies for CTP.

• Communications of the Korean Mathematical Society
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• v.35 no.2
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• pp.347-358
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• 2020

In this paper, we simplify the natural partial ordering ≼ on the semigroup 𝒪([n]) under composition of all order-preserving maps on [n] = {1, …, n}, and describe its maximal elements. Also, we show that the poset (𝒪([n]), ≼) is weakly graded and determine when (𝒪([n]), ≼) has a structure of (i + 1)-avoidance.

• Proceedings of the KIEE Conference
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• 2007.04a
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• pp.152-154
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• 2007

Anew discretization method for the input-driven nonlinear continuous-time system with time delay is proposed. It is based on the combination of Taylor series expansion and first-order hold assumption. The mathematical structure of the new discretization scheme is explored. The performance of the proposed discretization procedure is evaluated by case studies. The results demonstrate that the proposed discretization scheme can assure the system requirements even though under a large sampling period. A comparison between first order hold and zero-order hold is simulated also.