• Journal of Electrical Engineering and Technology
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• v.8 no.4
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• pp.879-888
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• 2013

This paper addresses the vision based local path planning system for obstacle avoidance. To handle the obstacles which exist beyond the field of view (FOV), we propose a Panoramic Environment Map (PEM) using the MDGHM-SIFT algorithm. Moreover, we propose a Complexity Measure (CM) and Fuzzy logic-based Avoidance Motion Selection (FAMS) system to enable a humanoid robot to automatically decide its own direction and walking motion when avoiding an obstacle. The CM provides automation in deciding the direction of avoidance, whereas the FAMS system chooses the avoidance path and walking motion, based on environment conditions such as the size of the obstacle and the available space around it. The proposed system was applied to a humanoid robot that we designed. The results of the experiment show that the proposed method can be effectively applied to decide the avoidance direction and the walking motion of a humanoid robot.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.924-926
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• 2006

Sensor networks are an emerging area of mobile computing. Networked sensors represent a new design paradigm enabled by advances in micro electro-mechanical systems (MEMS) and low power technology. Created with integrated circuit (IC) technology and combined with computational logic, these 'smart' sensors have the benefit of small size, low cost and power consumption, and, the capability to perform on-board computation. Though this recent technological innovation has shown a significant promise in many application domains, it has also exposed several technical limitations that must be improved. In this paper, we discuss the system deploy issues for infrared thermo sensor camera calibration.

• Journal of Power Electronics
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• v.15 no.4
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• pp.899-909
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• 2015

A dual-input boost-buck converter with coupled inductors (DIBBC-CI) is proposed as a thermoelectric generator (TEG) power conditioner with a wide input voltage range. The DIBBC-CI is built by cascading two boost cells and a buck cell with shared inverse coupled filter inductors. Low current ripple on both sides of the TEG and the battery are achieved. Reduced size and power losses of the filter inductors are benefited from the DC magnetic flux cancellation in the inductor core, leading to high efficiency and high power density. The operational principle, impact of coupled inductors, and design considerations for the proposed converter are analyzed in detail. Distributed maximum power point tracking, battery charging, and output control are implemented using a competitive logic to ensure seamless switching among operational modes. Both the simulation and experimental results verify the feasibility of the proposed topology and control.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.12
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• pp.1595-1601
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• 2018

The biggest obstacle to the commercialization of small and medium size microgrid (MG) is the reliability and economics of MG operation and maintenance. In this paper, we propose an autonomous operation method that is implemented as an application program installed in the MG operating system in emergency situations. The proposed algorithm consists of four steps of distinction, recognition, determination and control of emergency situations that can occur in MG. A fuzzy-based situation decision algorithm has been proposed to eliminate the barriers of autonomous operation in actual emergency situation such as occurrence of bad data and communication delay. In addition, countermeasures have been suggested for cases where multiple emergency situations have occurred in combination. The proposed algorithm was tested in a 500kW actual microgrid site of a university. Through the test, the validity of the proposed method and its applicability to practical MG operation are verified.

• Journal of the Regional Association of Architectural Institute of Korea
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• v.21 no.5
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• pp.161-168
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• 2019

The use of various digital tools makes freeform modeling possible. At the same time, with the development of structural and construction technologies, Free-Form Architecture are beginning to be implemented realized, as the desired data extraction such as the size and coordinate points of the members is possible. Currently, in many cities around the world, Irregular-Shaped High-rise Buildings, which express the dynamic symbolism, are recognized for their landmark values. In order to realize the Irregular-Shaped High-rise Buildings, it is necessary to understand various fields such as the characteristics of digital tools, digital technique logic, design process, and construction method. In particular, it is important to plan Irregular-Shaped High-rise Buildings so that the various types of efficiency can be reviewed together, while generating understanding and formations from the initial design stage. Therefore, this study uses conceptual and parametric design tools related to form generation in digital architecture to analyze the details, methods, and characteristics of the Irregular-Shaped High-rise Buildings form generation process. In this paper, the parametric design tool is applied to study the various types of design and the process characteristics that can be considered in the initial design stage of the unstructured skyscraper.

• The Journal of the Convergence on Culture Technology
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• v.9 no.1
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• pp.771-776
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• 2023

Scratchpad memory is a software-controlled on-chip memory designed and used to mitigate the disadvantages of existing cache memories. Existing cache memories have TAG-related hardware control logic, so users cannot directly control cache misses, and their sizes are large and energy consumption is relatively high. Scratchpad memory has advantages in terms of size and energy consumption because it eliminates such hardware overhead, but there is a burden on software to manage data. In this study, data management techniques of scratchpad memory were classified and examined, and ways to maximize the advantages were discussed.

• International conference on construction engineering and project management
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• 2013.01a
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• pp.304-307
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• 2013

Various programs have been developed to predict the energy consumption of a building as a result of recent increased social interest in the environmental friendliness of construction as measured by energy efficiency. The goal of environmental-friendliness, which is achieved by predicting the energy consumption of a building, can be realized in the design stage by applying a variety of technologies, planning factors and planning systems. However, most energy analyzing engines are only suitable for use in the advanced stages of design because of the large amount of design information that must be entered. Thus, because the simulation programs currently used are not suitable for use in the early stages of design, this study suggests a prediction logic that provides an overview of the energy consumption of a building according to its size, scope, and purpose by analyzing statistics collected by government agencies.

• The Korean Journal of Financial Management
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• v.26 no.1
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• pp.65-94
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• 2009

The event of change in KOSPI 200 Index composition is one of the main subjects for the test of EMH. According to EMH, when a certain event is not related with firm's fundamental value, stock price should not change after the announcement of news. This hypothesis leads us to the conclusion of horizontal demand curve of stock. This logic was questioned by Shleifer(1986) and argued that downward sloping demand curve hypothesis was supported. But Harris and Gruel(1986) found a different empirical evidence that price reversal occurs in the long run, which is called price pressure hypothesis. They argued that short term price effect by large block trading (price pressure) is offset in the long run because these event is unrelated to fundamental value. Therefor, they argued that EMH can not be rejected in the long run. Until now, there are two empirical studies with Korean market data in this area. Using a data with same time period of $1996{\sim}1999$, Kweon and Park(2000) and Ahn and Park(2005) showed that stock price or beta is not significantly affected by change in index composition. This study retested this event expanding sample period from 1996 to 2006, and analyzed why this event was considered an uninformative events in the preceding studies. We analyzed a market impact by separating samples according to firm size and market condition. In case of newly enlisted firm, we found the evidence supporting price pressure hypothesis on average. However, we found the long run price effect in the sample of large firms under bearish markets. At the same time, we know that the number of samples under the category of large firms under bearish markets is relatively small, which drives the same result of supporting the hypothesis that change in index composition is a non-informative event on average. Also, the long run price effect of large size firms under bearish markets was supported by the analyses using trading volumes. On the other hand, in case of delisting from the index, we found the long run price effect but that was not supported by trading volume analyses.

• Journal of the Economic Geographical Society of Korea
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• v.18 no.3
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• pp.267-280
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• 2015

The European civil aviation industry, which had lower technical skills, capital strength and market scale than the U.S., adopted the production system of joint development and division labor between the nations of Europe. Each plant locations strengthened their specialization of the production branch in the past 40 years with a geographical accumulation of the specialized manufacturing facilities, suppliers, universities and laboratories by the logic of geographical proximity and learning effect. The cargo plane transportation system in the production of short- and medium-haul aircraft facilitated the geographical dispersion of manufacturing process and the logistical linkage among the various plant locations. But the production of long-haul large aircraft(A380) chosen the transportation system by the cargo ship because of the size and weight. Considering the transportation system by the cargo ship, the choice of Toulouse as a final assembly plant location was the irrational locational decision from a locational point of view. This locational choice is explained by the merging process of the European civil aviation industry, the logic of learning effect and geographical proximity, and the active attraction support policy.

• Journal of KIISE:Software and Applications
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• v.30 no.3_4
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• pp.212-218
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• 2003

State invariant is a property that holds in every reachable state. It can be used not only in understanding and analyzing complex software systems, but it can also be used for system verifications such as checking safety, liveness, and consistency. For these reasons, there are many vital researches for deriving state invariant from finite state machine models. In previous works every reachable state is to be considered to generate state invariant. Thus it is likely to be too complex for the user to understand. This paper seeks to answer the question `how to simplify state invariant\ulcorner`. Since the complexity of state invariant is strongly dependent upon the size of states to be considered, so the smaller the set of states to be considered is, the shorter the length of state invariant is. For doing so, we let the user focus on some interested scopes rather than a whole state space in a model. Computation Tree Logic(CTL) is used to specify scopes in which he/she is interested. Given a scope in CTL, mixed reachability analysis is used to find out a set of states inside it. Obviously, a set of states calculated in this way is a subset of every reachable state. Therefore, we give a weaker, but comprehensible, state invariant.