• Journal of KIISE:Information Networking
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• v.33 no.6
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• pp.420-427
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• 2006

An RFID system is an important technology that could replace the traditional bar code system changing the paradigm of manufacturing, distribution, and service industry. An RFID reader can recognize several hundred tags in one second. Tag identification is done by tags' random transmission of their IDs in a frame which is assigned by the reader at each round. To minimize tag identification time, optimal frame size should be selected according to the number of tags. This paper presents new query optimization methods in RFID systems. Query optimization consists of tag number estimation problem and frame length determination problem. We propose a simple yet efficient tag estimation method and calculate optimal frame lengths that minimize overall query time. We conducted rigorous performance studies. Performance results show that the new tag number estimation technique is more accurate than previous methods. We also observe that a simple greedy method is as efficient as the optimal method in minimizing the query time.

• Steel and Composite Structures
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• v.45 no.1
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• pp.83-100
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• 2022

Timber is one of the few natural, renewable building materials and glulam is a type of engineering wood product. In the present work, timber-based braces are applied for retrofitting midrise Special Moment Resisting Frame (SMRF) using two types of timber base braces (Timber base glulam, and hybrid Timber-Steel-BRB) as alternatives for retrofitting by traditional steel bracings. The improving effects of adding the bracings to the SMRF on seismic characteristics of the frame are evaluated using load-bearing capacity, energy dissipation, and story drifts of the frame. For evaluating the retrofitting effects on the seismic performance of SMRF, a five-story SMRF is considered unretofitted and retrofitted with steel-hollow structural section (HSS) brace, Glued Laminated Timber (Glulam) brace, and hybrid Timber-Steel BRB. Using OpenSees structural analyzer, the performance are investigated under pushover, cyclic, and incremental loading. Results showed that steel-HSS, timber base Glulam, and hybrid timber-steel BRB braces have more significant roles in energy dissipation, increasing stiffness, changing capacity curves, reducing inter-story drifts, and reducing the weight of the frames, compared by steel bracing. Results showed that Hybrid BRB counteract the negative post-yield stiffness, so their use is more beneficial on buildings where P-Delta effects are more critical. It is found that the repair costs of the buildings with hybrid BRB will be less due to lower residual drifts. As a result, timber steel-BRB has the best energy dissipation and seismic performance due to symmetrical and stable hysteresis curves of buckling restrained braces that can experience the same capacities in tension and compression.

• Korean Institute of Interior Design Journal
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• no.14
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• pp.63-73
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• 1998

The aim of this study is to understand and redefine the nature of architectural environment within the paradigm of natural science. The chaos theory non-equilibrium thermodynamics theory self-organization of modern physics offer new insights to explain not only natural phenomena but also to define creative and dynamic architectural environment. First natural laws in modern physics like the arrow of time but is related not only with certainty but also possibility so nature is understood as a constantly changing process of evolution. Second the new architectural environment is defined as a kind of fluid and irreducible organic biosytem that cannot be fully understood by modernist idea of architecture. It is conceived of as a fluid constantly changing self-oraganizing system that consists of different situations events movements and programs in uncertain and irreducible time frame. Third insights and implications of natural science offer new language and strategy for design and the two disciplines can be understood as interdependent and co-evolving

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.1
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• pp.69-74
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• 2012

In this research equations of motion of a Wheeled Inverted Pendulum (WIP) which is running on the inclined road and changing its center of gravity. Difference between a conventional cart inverted pendulum and the WIP is also considered. The WIP has small planar size so that it has been used as a mobile platform for several applications which require slender frame in order to travel on the narrow road. The WIP has almost the same unstable properties as conventional inverted pendulums have. There needs an aggressive control scheme for the WIP not to fall down. In order to design a high performance control scheme, equations of motion of the WIP, which is running under various environment and operating conditions, should be derived and considering its properties is necessary.

• Korean journal of communication and information
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• v.79
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• pp.104-139
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• 2016

This study investigated how Korean media covered Japan's position on her past history issues proposed by Abe' Shinzo's cabinet. The researchers adopted Entman's analytical tools for frame analysis and the concept of "frame changing" proposed by Chi and McCombs. The analysis rendered several propositions. First of all, the Korean media's coverage on Japan's past history issues focused heavily on the current conflict among two nations rather than constructing a futuristic viewpoint based on a thorough discussion on the historical background of the topic. In addition, it emphasized that the conflict should be resolved by political negotiations between the two governments. Secondly, the news coverages depicted "comfort women" issues as the prime element of the conflict, describing Abe's cabinet as the major inducer of the conflict. Ideological and political divisions among Korean media did not significantly influence on how they frame Japan's past history issues. In general, Korean media took the stance of ethnocentric "patriotic journalism," advocating Korean government's position and covering the emotional reactions from Korean public instead of providing through and through objective news coverage on Japan's past history issues.

• Korean Institute of Interior Design Journal
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• v.21 no.2
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• pp.84-91
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• 2012

The total data of observing interior space was divided into a few time frames for analysis. If we can understand the changing process of observation degree as the observation time passes, we will be able to analyse the characteristic and process of information obtainment in the case of space observation. For this purpose, the observation time was parted into 30 second units and the changing characteristic by time frame and observation area was analysed. The conclusion derived from this study is as the following: First, analysis of observation frequency and time on the basis of the average data of each subject showed that the observation time increased compared with the subject's frequency and the overall trend but that it was difficult for me to think there was a certain trend in the observation time of each subject. However, when I examined the time change by using the trend line which is a dynamic average line representing the observation time from the subjects as the trend element of time series, I could see the trend that the subject's observation time increased at a fixed rate as the frequency increased. Second, when I compared and analysed the average observation area at Area I set up by the time of 30 second unit and the observation area of Area I from the all data, I could see that the former had more degree of concentration at Area I. This analysis enabled me to get the degree of concentration on the observed area every time, and accordingly I could also see that when the data of intensive observation by time frame is analysed, the degree of concentration is dispersed for the subjects to observe very intensively or the area with overlapping observations each time frame can be seen as Area I out of the entire observation data. Third, when I analysed the observation characteristics by time frame at the 6 areas divided at 30 second unit at the rate of the number to the time of observation areas, I could see that as the observation time passed while the number of the observation areas defined as decreased the observation time increased, which means that when the area numbers decreases the area intensively observed by the subjects decreases as the time passes. In spit of that, the increase of time can be interpreted as more intensive observation of a specific area.

• Journal of the Korea Concrete Institute
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• v.27 no.4
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• pp.363-375
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• 2015

This research investigated the effects of diameter and material of energy frame on the impact velocity or strain rate of Strain Energy Frame Impact Machine (SEFIM). The impact speed of SEFIM have been clearly affected by changing the diameter and material of the energy frame. The reduced diameter of the energy frame clearly increased the impact velocity owing to the higher strain at the moment of coupler breakage. And, titanium alloy energy frame produced the fastest speed of impact among three materials including steel, aluminum and titanium alloys because titanium alloy has faster wave velocity than steel. But, aluminium energy frame was broken during impact tests. In addition, the tensile stress versus strain response of high performance fiber reinforced cementitious composites at higher and wider strain rates between 10 and 72 /sec was successfully obtained by using four different energy frames.

• The KIPS Transactions:PartB
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• v.14B no.3 s.113
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• pp.171-182
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• 2007

We propose a simple method for tracking a nonparameterized subject contour in a single video stream with a moving camera and changing background. Then we present a method to eliminate the tracked contour object by replacing with the background scene we get from other frame. First we track the object using LOD (Level-of-Detail) canny edge maps, then we generate background of each image frame and replace the tracked object in a scene by a background image from other frame that is not occluded by the tracked object. Our tracking method is based on level-of-detail (LOD) modified Canny edge maps and graph-based routing operations on the LOD maps. We get more edge pixels along LOD hierarchy. Our accurate tracking is based on reducing effects from irrelevant edges by selecting the stronger edge pixels, thereby relying on the current frame edge pixel as much as possible. The first frame background scene is determined by camera motion, camera movement between two image frames, and other background scenes are computed from the previous background scenes. The computed background scenes are used to eliminate the tracked object from the scene. In order to remove the tracked object, we generate approximated background for the first frame. Background images for subsequent frames are based on the first frame background or previous frame images. This approach is based on computing camera motion. Our experimental results show that our method works nice for moderate camera movement with small object shape changes.

• Proceedings of the Korea Information Processing Society Conference
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• 2007.05a
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• pp.333-336
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• 2007

We propose a simple method for tracking a nonparameterized subject contour in a single video stream with a moving camera and changing background. Then we present a method to eliminate the tracked contour object by replacing with the background scene we get from other frame. Our method consists of two parts: first we track the object using LOD (Level-of-Detail) canny edge maps, then we generate background of each image frame and replace the tracked object in a scene by a background image from other frame that is not occluded by the tracked object. Our tracking method is based on level-of-detail (LOD) modified Canny edge maps and graph-based routing operations on the LOD maps. To reduce side-effects because of irrelevant edges, we start our basic tracking by using strong Canny edges generated from large image intensity gradients of an input image. We get more edge pixels along LOD hierarchy. LOD Canny edge pixels become nodes in routing, and LOD values of adjacent edge pixels determine routing costs between the nodes. We find the best route to follow Canny edge pixels favoring stronger Canny edge pixels. Our accurate tracking is based on reducing effects from irrelevant edges by selecting the stronger edge pixels, thereby relying on the current frame edge pixel as much as possible. This approach is based on computing camera motion. Our experimental results show that our method works nice for moderate camera movement with small object shape changes.

• Journal of Navigation and Port Research
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• v.29 no.1 s.97
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• pp.77-82
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• 2005

According as the quantity of goods transported by ship is increasing, a port environment is rapidly changing To meet this situation successfully, the development of the next generation port loading and unloading system(LMTT) is studied A Frame of shuttle car for LMTT(Linear Motor-based Transfer Technology) consists of three parts which are outer beam, inner beam and cross beam In this study, we carried out the finite element analysis for the effect of cross beam on the strength and stiffness of the frame according to the number of cross beam, loading position of container, the distance ratio of inner beam from center. The result is as follow ; When the load is applied on outer beam and inner beam concurrently and the number of cross beam is 5, that is the optimum condition in frame design.