• 대한기계학회논문집A
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• 제28권7호
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• pp.1029-1037
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• 2004

High-speed/precision servomechanisms have been widely used in the manufacturing and semiconductor industries. In order to ensure the required high-speed and high-precision specifications in servomechanisms, an integrated design methodology is required, where the interactions between mechanical and electrical subsystems will have to be considered simultaneously. For the first step of the integrated design process, it is necessary to obtain not only strict mathematical models of separate subsystems but also formulation of an integrated design problem. A two-degree-of-freedom controller described in the discrete-time domain is considered as an electrical subsystem in this paper. An accurate identification process of the mechanical subsystem is conducted to verify the obtained mathematical model. Mechanical and electrical constraints render the integrated design problem accurate. Analysis of the system performance according to design and operating parameters is conducted for better understanding of the dynamic behavior and interactions of the servomechanism. Experiments are performed to verify the validity of the integrated design problem in the x-Y positioning system.

• Journal of Computational Design and Engineering
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• 제2권4호
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• pp.248-252
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• 2015

Currently composite manufacturing process, such as linear friction welding plus NC machining, is the main method for the manufacturing and repairing of complex parts with integrated structure. Due to different datum position and inevitable distortion from different processes, it is important to ensure sufficient machining allowance for complex parts during the NC machining process. In this paper, a workpiece localization approach for machining allowance optimization of complex parts based on CMM inspection is developed. This technique concerns an alignment process to ensure sufficient stock allowance for the single parts as well as the whole integrated parts. The mathematical model of the constrained alignment is firstly established, and then the symmetric block solution strategy is proposed to solve the optimization model. Experiment result shows that the approach is appropriate and feasible to distribute the machining allowance for the single and whole parts for adaptive machining of complex parts.

• ETRI Journal
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• 제46권2호
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• pp.277-289
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• 2024

In this paper, we describe a neural network-based application that recommends multiple items using dialog context input and simultaneously outputs a response sentence. Further, we describe a multi-item recommendation by specifying it as a set of clothing recommendations. For this, a multimodal fusion approach that can process both cloth-related text and images is required. We also examine achieving the requirements of downstream models using a pretrained language model. Moreover, we propose a gate-based multimodal fusion and multiprompt learning based on a pretrained language model. Specifically, we propose an automatic evaluation technique to solve the one-to-many mapping problem of multi-item recommendations. A fashion-domain multimodal dataset based on Koreans is constructed and tested. Various experimental environment settings are verified using an automatic evaluation method. The results show that our proposed method can be used to obtain confidence scores for multi-item recommendation results, which is different from traditional accuracy evaluation.

• 대한산업공학회지
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• 제11권2호
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• pp.29-37
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• 1985

This paper studies a production-inventory model which unifies the inventory problem of raw materials and the finished product for a single product manufacturing system. The integrated production-inventory model is formulated wth a nonlinear mixed integer programming problem. An algorithm is developed by utilizing the finite explicit enumeration method. The algorithm guarantees to generate an optimal policy for minimizing the total annual variable cost. A mumerical example involving 15 raw materials is given to illustrate the recommended solution procedure.

• 한국국방경영분석학회지
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• 제18권2호
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• pp.23-43
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• 1992

A Stochastic simulation model for optimal design and evaluation of the integrated weapon systems under the consideration of the RAM (reliability, availability and maintainability) and life cycle cost (LCC) was developped. This model is supposed to satisfy a need regarding the methodology of optimaldesign and performance evaluation for both developpers and users of weapon systems.

• KDI Journal of Economic Policy
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• 제38권2호
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• pp.87-101
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• 2016

A person's life consists of two important stages: the first stage as a student and the second stage as a worker. In an integrated model of education and career concerns, I analyze the welfare effects of education. In Spence's job market signaling model, education as a sorting device improves efficiency by mitigating the lemon market problem. In contrast, in the integrated model, education as a sorting device can be detrimental to social welfare, as it eliminates work incentives generated by career concerns.

• 한국환경과학회지
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• 제17권9호
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• pp.993-1003
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• 2008

Interior space in most buildings is divided into several zones. The most important factors relating to the indoor air environment are temperature, airflow, humidity, and contaminant concentration. An integrated multizone model to predict these environmental factors simultaneously was developed. Also, a computer program for this model was written by the language of VISUAL BASIC. The proposed model was applied to a apartment with five rooms that had been tested by Chung. Comparison of predicted results by this study with measured results by Chung showed that their variations were within 14% for airflow rates, 1% for temperatures, 12% for humidities, and 5% for concentrations. It was seen that the opening operation schedule of building has a significant effect on the air moisture md contaminant removal. Thus, this model may be available for predicting the indoor air environment and may be contributed to design the ventilation plan for controling of indoor air quality.

• 정보교육학회논문지
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• 제14권2호
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• pp.157-164
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• 2010

이 연구에서 초등학생을 위한 정보보호 지식과 태도, 기능을 통한 실천능력의 신장을 고려한 정보보호 통합학습모형을 제안하였다. 이를 위해 첫째, 초등학교의 교육과정 중 정보보호 교육내용을 추출한 뒤 정보보호교육내용을 지식, 태도, 기능, 실천적 관점에서 분석했다. 둘째, 효과적인 정보보호교육을 위해 지식, 태도, 기능, 실천이 종합된 KASP-정보보호 통합학습모형을 개발하고 그에 따른 지도안과 학습전략을 개발하였다. 셋째, 개발된 모형을 실험집단에 적용하고 비교집단에는 일반적 정보보호교육 내용을 적용하여 비교집단과의 전후좌우비교를 실시하여 효과성을 검증하였다. 검사결과 이 연구에서 개발된 KASP-정보보호 통합학습모형이 학생들의 정보보호 지식 및 태도, 기능뿐만 아니라 실천능력에도 효과적임을 보였다.

• 대기
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• 제34권2호
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• pp.217-231
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• 2024

The Korea Integrated Model (KIM)-based real-time volcanic ash dispersion prediction system, which employs the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model, has been developed to quantitatively predict volcanic ash dispersion in East Asia and the Northwest Pacific airspace. This system, known as KIM-HYSPLIT, automatically generates forecasts for the vertical and horizontal spread of volcanic ash up to 72 hours. These forecasts are initiated upon the receipt of a Volcanic Ash Advisory (VAA) from the Tokyo Volcanic Ash Advisory Center by the server at the Korea Meteorological Administration (KMA). This system equips KMA forecasters with diverse volcanic ash prediction information, complemented by the Unified Model (UM)-based HYSPLIT (UM-HYSPLIT) system. Extensive experiments have been conducted using KIM-HYSPLIT across 128 different volcanic scenarios, along with qualitative comparisons with UM-HYSPLIT. The results indicate that the ash direction predictions from KIM-HYSPLIT are consistent with those from UM-HYSPLIT. However, there are slight differences in the horizontal extent and movement speed of the volcanic ash. Additionally, quantitative verifications of the KIM-HYSPLIT forecasts have been performed, including threat score evaluations, based on recent eruption cases. On average, the KIMHYSPLIT forecasts for 6 and 12 hours show better quantitative alignment with the VAA forecasts compared to UM-HYSPLIT. Nevertheless, both models tend to predict a broader horizontal spread of the ash cloud than indicated in the VAA forecasts, particularly noticeable in the 6-hour forecast period.

• 한국자동차공학회논문집
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• 제22권6호
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• pp.59-67
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• 2014

A numerical model and a controller of Active Front wheel Steer (AFS) system are designed in this study. The AFS model consists of four sub models, and the AFS controller uses sliding mode control and PID control methods. To test this model and controller an Integrated Dynamics Control with Steering (IDCS) system is also designed. The IDCS system integrates an AFS system and an ARS (Active Rear wheel Steering) system. The AFS controller and IDCS controller are compared under several driving and road conditions. An 8 degree of freedom vehicle model is also employed to test the controllers. The results show that the model of AFS system shows good kinematic steering assistance function. Steering ratio varies depends on vehicle velocity between 12 and 24. Kinematic stabilization function also shows good performance because yaw rate of AFS vehicle tracks the reference yaw rate. IDCS shows improved responses compared to AFS because body side slip angle is also reduced. This result also proves that AFS system shows satisfactory result when it is integrated with another chassis system. On a split-m road, two controllers forced the vehicle to proceed straight ahead.