• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.1
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• pp.73-81
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• 2013

In this paper, we have proposed the interference analysis method which uses both an interference probability model at the PHY layer of RFID system and the DTMC model at the MAC layer of USN system. Using the proposed method, we have performed sharing analysis between passive RFID and USN systems at the Korean RFID/USN frequency bands. If 1% performance degradation of USN system is allowed, RFID and USN systems can share the frequency bands where channel number is greater or equal to 20 on condition that radius of protection area is greater than 300 m.

• Journal of the Korean Society of Safety
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• v.31 no.3
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• pp.156-161
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• 2016

An accident of an ammonia tank pipeline at a storage plant resulted in one death and three injuries in 2014. Many accidents including toxic gas releases and explosions occur in the freezing and refrigerating systems using ammonia. Especially, the consequence can be substantial due to that the large amount of ammonia is usually being used in the refrigeration systems. In this study, offsite consequence analysis has been investigated when ammonia leaks outdoors from large storages. Both flammable and toxic effects are under consideration to calculate the affected area using simulation programs for consequence analysis. ERPG-2 concentration (150 ppm) has been selected to calculate the evacuation distance out of various release scenarios for their dispersions in day or night. For offsite residential, the impact area by flammability is much smaller than that by toxicity. The methodology consists of two steps as followings; 1. Calculation for discharge rates of accidental release scenarios. 2. Dispersion simulation using the discharge rate for different conditions. This proactive prediction for accidental releases of ammonia would help emergency teams act as quick as they can.

• International Journal of Advanced Culture Technology
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• v.11 no.3
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• pp.346-357
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• 2023

The purpose of this study is to suggest improvement plans for prevention regulations by reflecting the toxicity, fire and explosion effects of hazardous materials factories and surrounding areas using an off-site consequence assessment program. Regarding the effects of the hydrogen cyanide leak accident, which is the 1st petroleum of the 4th class flammable liquid, Areal Locations of Hazardous Atmospheres (ALOHA) program was used to compare and analyze the extent of damage effects for toxicity, overpressure, and radiation. As a result, the toxicity was analyzed to exceed 5km in the area with Acute exposure guideline level (AEGL)-2 concentration or higher, the overpressure was 103m in the range of 1 psi or more, and the radiant heat was analyzed to be 724m in the range of 2kw/m² or more. Toxicity and radiation affected the area outside the hazardous material storage area, but the overpressure was limited to the inside of the hazardous material storage area. Therefore, we propose to improve the safety management of hazardous materials by conducting a risk assessment for hazardous materials and reflecting the results in internal and external emergency response plans to prepare prevention regulations.

• Fashion & Textile Research Journal
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• v.26 no.3
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• pp.265-272
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• 2024

In the current era of rapid digitization of the fashion industry, this study aims to facilitate the digitization of local Hawaiian fashion products. The research compares and analyzes the patterns and colors of digital clothing products sold on Zepeto, a metaverse platform, and those of physical products sold both, online and offline, by six specialized brands with stores in Honolulu, Hawaii, or Hawaiian signature clothing products. The following results were obtained: First, physical products generally display various patterns, such as animals, plants, geography, regions, and beaches. However, the pattern diversity of digital products is relatively limited, with a tendency to focus on plant and animal designs, which are Hawaii's signature patterns. Second, the color analysis results demonstrate that chromatic color groups, such as blue and red, were the most popular in physical products, whereas digital products used mostly green and neutral colors. Considering that physical products are sold both, online and offline, this is presumed to be due to differences in expression techniques and customer responses to digital and physical products, rather than market differences. To facilitate the digitization of Hawaiian local fashion products, a library that accommodates physical products in a variety of patterns and colors must be secured, and continuous modifications must be made to match the overall fashion trends.

• Journal of Internet Computing and Services
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• v.14 no.5
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• pp.1-10
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• 2013

RFID(Radio Frequency Identification) system is non-contact identification technology. A basic RFID system consists of a reader, and a set of tags. RFID tags can be divided into active and passive tags. Active tags with power source allows their own operation execution and passive tags are small and low-cost. So passive tags are more suitable for distribution industry than active tags. A reader processes the information receiving from tags. RFID system achieves a fast identification of multiple tags using radio frequency. RFID systems has been applied into a variety of fields such as distribution, logistics, transportation, inventory management, access control, finance and etc. To encourage the introduction of RFID systems, several problems (price, size, power consumption, security) should be resolved. In this paper, we proposed an algorithm to significantly alleviate the collision problem caused by simultaneous responses of multiple tags. In the RFID systems, in anti-collision schemes, there are three methods: probabilistic, deterministic, and hybrid. In this paper, we introduce ALOHA-based protocol as a probabilistic method, and Tree-based protocol as a deterministic one. In Aloha-based protocols, time is divided into multiple slots. Tags randomly select their own IDs and transmit it. But Aloha-based protocol cannot guarantee that all tags are identified because they are probabilistic methods. In contrast, Tree-based protocols guarantee that a reader identifies all tags within the transmission range of the reader. In Tree-based protocols, a reader sends a query, and tags respond it with their own IDs. When a reader sends a query and two or more tags respond, a collision occurs. Then the reader makes and sends a new query. Frequent collisions make the identification performance degrade. Therefore, to identify tags quickly, it is necessary to reduce collisions efficiently. Each RFID tag has an ID of 96bit EPC(Electronic Product Code). The tags in a company or manufacturer have similar tag IDs with the same prefix. Unnecessary collisions occur while identifying multiple tags using Query Tree protocol. It results in growth of query-responses and idle time, which the identification time significantly increases. To solve this problem, Collision Tree protocol and M-ary Query Tree protocol have been proposed. However, in Collision Tree protocol and Query Tree protocol, only one bit is identified during one query-response. And, when similar tag IDs exist, M-ary Query Tree Protocol generates unnecessary query-responses. In this paper, we propose Adaptive M-ary Query Tree protocol that improves the identification performance using m-bit recognition, collision information of tag IDs, and prediction technique. We compare our proposed scheme with other Tree-based protocols under the same conditions. We show that our proposed scheme outperforms others in terms of identification time and identification efficiency.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2008.05a
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• pp.869-872
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• 2008

This paper presents the VHDL implementation procedure of the passive RFID tag in Ultra High Frequency RFID system. The operation of the tag compatible with the EPCglobal Class1 Generation2(GEN2) protocol is verified by timing simulation after synthesis and implementation on prototyping board. Due to the reading range with relatively large distance, a passive tag needs digital processor which facilitates faster decoding, encoding and state transition for enhancement of the interrogation rate. Also with UART communication, verify a inventory Round in Gen2 Protocol. The verification results with the fastest data rate, 640kbps, and multi tags environment scenario show that the implemented tag spend 1.4ms transmitting the 96bits EPC to reader.

• The Research Journal of the Costume Culture
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• v.8 no.3
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• pp.460-476
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• 2000

The purpose of this study was, accordingly, to examine male college student's general body consciousness and their actual condition of wearing clothing, as it's assumed that clothing, which everyone must always wear, might be effective in making up for the physical defect. The findings of this study were as follows : 1. Male College Students'Body Consciousness : They expressed some dissatisfaction with their own body, and they were most discontented with their height, among their bodies. They thought of the western-style shape as an ideal one, as what's considered by them to be ideal was thinner a little than them, being taller with wider shoulder, longer legs, smaller and white face. 2. Male College Students'Characteristics of Clothing Purchasing Behavior : In purchasing clothing, male college students were slightly sensitive about the physical part with which they wasn't satisfied. The clothing pattern preferred by them was an abstract one, and their favorite color was white or black. The greatest number of them put most emphasis on design in buying clothing, and they purchased clothing mainly at special fashion shop. On the whole, they showed an affirmative response toward wearing Korean costume, and they also had a positive opinion about the purchase of reformed Korean dress for everyday life. 3. Male College Students'Characteristics of Wearing Clothing : They appeared not to consider making up for physical weakness. Male college students favored aloha shirt and trousers when they went out. Male college students purchase clothing in consideration of individual, manly, classical, tender, or comfortable factors. 4. Relationship of Body Consciousness to Wearing Behavior : The degree to which they considered covering up physical weakness in wearing clothing was examined, by dividing them into two groups : one was a group that thought their own shape normal, and the other was a group that didn't think of their own shape as normal. As a result, both groups appeared not to consider covering up physical weakness.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.3
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• pp.373-378
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• 2006

One of the biggest problems that should be solved in present RFID systems is a reduction of identification efficiency by the collision of singals between different tags. As the number of tags, which should be identified, increases over the size of allocated round, more slots experiences the collision between them. It can causes generation of tag collision assigning the fixed round size and so, allocated round size should be regulated properly. This paper proposes the algorithm which can reduce collision between tags, and allocate specific round size dynamically for efficient tag identification. After each round is finished, the reader allocates the round size dynamically using the collision information of the slot. All collision informations of the slot consists of the number of slots which came into conflict, tags which were realized properly without any conflictions and empty slots. We used slotted aloha algorithm as the collision detection algorithm and finally, checked that this could be used very usefully when this algorithm which was proposed effectively could not know how many number of tags were exisisted through the simulation in advance.

• Journal of the Korean Society of Clothing and Textiles
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• v.30 no.7 s.155
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• pp.1135-1145
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• 2006

The purpose of this study was to identify the desired seIf-images of male college students according to situations, and to construct fashion product unities bought by male college students for different situations. Empirical data were collected by self-administered questionnaires distributed to male students at 4 universities and 2 colleges in Daegu and Gyeongbuk area during June 2005, and 346 were analyzed, eliminating incomplete ones. Subjects were required to respond to 32 desired image words in 4 different situations respectively: school, meeting girlfriends, ceremonies, and exercises. As a result of factor analysis on desired self-image words, 5 factors were determined: refined image, sporty image, classic image, natural image and simple image. Based on the desired self-image factors, male college students were classified into 3 groups: selective image management group, passive image management group, and active Image management group. Fashion product unity of male college students for the school setting was consisted of round shirts, jeans, running shoes, bags and watches. Aloha shirts/knitted shirts/V-neck shirts, cotton pants/jeans/semi -formal pants, formal shoes/running shoes and watches were the fashion product unity for the setting of meeting girlfriends. For the setting of ceremonies, the fashion product unity included Y-shirts, formal dress, formal shoes, neckties and watches. And for the setting of exercises, the fashion product unity included cotton shirts, training suits, running shoes/jogging shoes/basketball shoes, armguard and caps.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.10 no.5
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• pp.364-371
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• 2017

TPMS is a vehicle electric system that measures the air pressure of a tire, and informs the driver of current tire states. The TPMS sensor typically uses unidirectional communication for small size, light weight, and low power. The transmission period of the sensor indicates the service quality of monitoring the tire. In order to determine the optimal transmission period, frame collision probability and the life time of the sensor should be analyzed. In this paper, collision probability model using Venn diagram is designed in low power TPMS with the normal and warning mode. And the life time and a collision probability were analyzed with the ratio(n) of the normal mode to warning mode transmission period. As a result, $T_{nP}=31sec$ and $T_{wP}=2.4sec$ at 5 years, and $T_{nP}=71sec$ and $T_{wP}=2.5sec$ at 7 years.