• 대한기계학회논문집B
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• 제41권4호
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• pp.277-283
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• 2017

본 연구에서는 높이에 따른 점프 전략 변화를 이해하기 위해 반동을 이용한 수직 점프 시 상변화 시점에서의 지면반력 벡터가 높이에 따라 어떻게 변하는지 분석하였다; 반동과 추진 구간에서 유사한 힘 작용선을 갖는 수직 점프의 경우, 상변화 시점에서 반동의 이득을 나타내는 합력 벡터의 크기와 방향이 일정한 경향성을 가지고 높이에 따라 변화할 것이라 가정하였다. 9명의 청년군 모두는 정해진 5 종류의 높이를 총 5세트에 걸쳐 랜덤 방식으로 점프하였으며, 해당 높이를 유도하기 위해 지면으로부터 191 cm에서 221 cm 사이에 일정한 간격을 두고 마커를 배치하였다. 점프 높이가 증가함에 따라 반동 시 무게중심을 낮추고, 수평, 수직 방향의 힘을 증가시키는 것이 관찰되었는데, 이는 추진일을 증가시키기 위해 관절의 가용범위를 넓히고 초기 힘(또는 가속도) 이득을 늘리기 때문으로 생각된다.

• Journal of Information Processing Systems
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• 제5권2호
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• pp.105-116
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• 2009

To solve the general problems surrounding the application of genetic algorithms in stereo matching, two measures are proposed. Firstly, the strategy of simplified population-based incremental learning (PBIL) is adopted to reduce the problems with memory consumption and search inefficiency, and a scheme for controlling the distance of neighbors for disparity smoothness is inserted to obtain a wide-area consistency of disparities. In addition, an alternative version of the proposed algorithm, without the use of a probability vector, is also presented for simpler set-ups. Secondly, programmable graphics-hardware (GPU) consists of multiple multi-processors and has a powerful parallelism which can perform operations in parallel at low cost. Therefore, in order to decrease the running time further, a model of the proposed algorithm, which can be run on programmable graphics-hardware (GPU), is presented for the first time. The algorithms are implemented on the CPU as well as on the GPU and are evaluated by experiments. The experimental results show that the proposed algorithm offers better performance than traditional BMA methods with a deliberate relaxation and its modified version in terms of both running speed and stability. The comparison of computation times for the algorithm both on the GPU and the CPU shows that the former has more speed-up than the latter, the bigger the image size is.

• 제어로봇시스템학회논문지
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• 제3권1호
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• pp.23-31
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• 1997

The sway control problem of pendulum motion of a container hanging on a Portainer Crane, which transports containers from a container ship to trucks, is considered in the paper. The equations of motion are obtained through the Lagrange mechanics and simplified for control purposes. Considering that the fast traveling of trolley and no residual swing motion of the container at the end of acceleration and deceleration are crucial for quick transportation, several velocity patterns of trolley movement including the time-optimal control are investigated. Incorporating the change of rope length, a reference swing trajectory is introduced in the control loop and the error signal between the reference sway angle and the measured sway angle is feedbacked. Proposed control strategy is shown to be robust to disturbances like winds and initial sway motion.

• 한국정보처리학회논문지
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• 제6권8호
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• pp.2113-2123
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• 1999

부분 자유어순 특성을 가지는 한국어를 CFG형태의 문법으로 기술했을 때 문법이 방대해지고 CFG형태의 문법을 파서가 이용할 때는 자연발화문의 특징인 간투어, 중복발화 등 때문에 불필요 성분을 따로 처리해야 하므로 파서의 부담이 커진다. 이러한 문제점을 해결하기 위해 본 논문에서는 발화문에서 중요한 의미를 가지는 요소를 '핵심개념'이라 정의하고 핵심개념만을 문법에 기술하여 문법이 방대해지는 것을 막고 문법에 기술된 핵심개념을 파싱요소로 선택함으로써 불필요 성분처리에 대한 파서의 부담을 줄였으며 이렇게 단순화된 문법만으로도 정확한 파싱결과를 내줄 수 있음으로 보인다. 실험결과 '여행안내'영역 자연발화문에 대해서 평균 98%이상의 올바른 파싱결과를 얻어낼 수 있었다.

• Journal of Power Electronics
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• 제15권4호
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• pp.1093-1104
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• 2015

A standard repetitive controller (RC) is theoretically able to replace a bank of resonant controllers in harmonic signals tracking applications. However, the traditional RC has some drawbacks such as a poor dynamic response and a complex structure to compensate grid frequency deviations for an effective unified power quality conditioner (UPQC) control scheme. In order to solve these problems, an improved RC with an outstanding dynamic response and a simplified grid frequency adaptive scheme is proposed for UPQC control systems in this paper. The control strategy developed for the UPQC has delay time, i.e., one-sixth of a fundamental period (T_p/6), repetitive controllers. As a result, the UPQC system can provide a fast dynamic response along with good compensation performance under both nonlinear and unbalanced loads. Furthermore, to guarantee the excellent performance of the UPQC under grid frequency deviations, a grid frequency adaptive scheme was developed for the RC using a simple first order Padé's approximation. When compared with other approaches, the proposed control method is simpler in structure and requires little computing time. Moreover, the entire control strategy can be easily implemented with a low-cost DSP. The effectiveness of the proposed control method is verified through various experimental tests.

• Journal of Power Electronics
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• 제19권4호
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• pp.989-999
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• 2019

This paper proposes a fault-tolerant control strategy with finite control set model predictive control (FCS-MPC) based on hierarchical optimization for five-level H-bridge neutral-point-clamped (5L-HNPC) inverter-fed induction motor drives. Fault-tolerant operation is analyzed, and the fault-tolerant control algorithm is improved. Adopting FCS-MPC based on hierarchical optimization, where the voltage is used as the controlled objective, called model predictive voltage control (MPVC), the postfault controller is simplified as a two layer control. The first layer is the voltage jump limit, and the second layer is the voltage following control, which adopts the optimal control strategy to ensure the current following performance and uniqueness of the optimal solution. Finally, simulation and experimental results verify that 5L-HNPC inverter-fed induction motor drives have strong fault tolerant capability and that the FCS-MPVC based on hierarchical optimization is feasible.

• Journal of Information Technology Applications and Management
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• 제25권3호
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• pp.55-66
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• 2018

Early smart-work of company K was a technology-led way of applying ICT such as smart phones and mobile devices to business. After company K perceived the limitations of ICT-driven smart work, it propelled the work-smart, doing a work smart toward the way that human beings become central and a creative organizational culture is engendered. Company K propelled work-smart strategy in eight categories: simplification of data requirements, establishment efficient meeting culture, streamlining reporting and approval process, simplified document creation, overtime decrease, spreading flexible work system, settlement of healing leave, creating work-smart place. Company K set up an organizational culture secretariat dedicated to work-smart promotion and selected task priorities in consideration of urgency and effectiveness. Owing to such efforts, the company K's work-smart index rose sharply to 72 points this year from 56 points in the previous year. At the organizational culture survey, employees responded that organizational culture improved in all area. For a better future, company K analyzed its work-smart outcomes and planned progressively to improve its work-smart efforts based on employees opinions. This case study will serve as a guideline, for companies to make efforts to going forward to today work-smart beyond yesterday smart-work.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회/대한산업공학회 2005년도 춘계공동학술대회 발표논문
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• pp.904-913
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• 2005

This paper deals with an integrated problem of inventory control and dynamic pricing strategies for a commodity with price and sales-period dependent demand pattern, where a seller and customers have complete information of each other. The problem consists of two parts; one is each buyer's benefit problem which makes the best decision on price and time for buyer to purchase items, and the other one is a seller's profit problem which decides an optimal sales strategy concerned with inventory control and discount schedule. The seller's profit function consists of sales revenue and inventory holding cost functions. The two parts are closely related into each other with some related variables, so that any existing general solution methods can not be applied. Therefore, a simplified model with single seller and two customers in considered first, where demand for multiple units is allowed to each customer within a time limit. Therewith, the model is generalized for a n-customer-classes problem. To solve the proposed n-customer-set problem, a dynamic programming algorithm is derived. In the proposed dynamic programming algorithm, an intermediate profit function is used, which is computed in case of a fixed initial inventory level and then adjusted in searching for an optimal inventory level. This leads to an optimal sales strategy for a seller, which can derive an optimal decision on both an initial inventory level and a discount schedule, in $O(n^2)$ time. This result can be used for some extended problems with a small customer set and a short selling period, including sales strategy for department stores, Dutch auction for items with heavy holding cost, open tender of materials, quantity-limited sales, and cooperative buying in the on/off markets.

• 한국항해항만학회지
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• 제36권4호
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• pp.285-290
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• 2012

e-Navigation strategy IMO promotes is defined as it is necessary for network and information standard to provide various maritime safety informations to in land and on board users, and it is expected to provide a large amount and diverse kinds of maritime spatial information services to them. However, as there are some limits to transmit that by current mobile maritime communication technologies, it is required to simplify and optimize the information. In this study, tree node method is applied to ENC using Douglas-Peucker algorithm and we arranged the effect of simplified spatial information through CALS method which compensates the defect of basic tree node method.

• 한국조리학회지
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• 제6권2호
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• pp.123-134
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• 2000

The food service industry represents one of Korea's fastest-growing and most challenging areas of business but it is at the beginning of the industry. Italian cooking of the food service industry has a lot of merits but it is difficult to manage because of the shortage of domestic customers and the poor management of the industry. This research suggests the marketing strategies in order to systematize Italian food service satisfy the customers requirements and promote the sale of Italian food. The circulation structures should be simplified and systematized in order to enhance the quality of the food and lower the price. Italian food should be recognized as health food cooked with unsaturated fatty acid, olive oil. It is necessary that the Italian food for the Korea especially for the women and children be developed. The information about Italian food the advertisement of it should be structured because 13 percent of Italian food sale has dropped in the current environment.