• Journal of the Ergonomics Society of Korea
• /
• v.20 no.3
• /
• pp.61-76
• /
• 2001

This study is for analyzing the explosion accidents in the tunnels, roads, subways, streets and various kinds of building construction area with the use of Fault Tree Analysis(FTA). based on the police Department and Guns & Explosives Safety Technology Association's researching materials. the explosion accidents have been investigated and analyzed between 1988 and 1977. As the result, we can find out that the majority of the explosion accidents in Korea is the accidents by flown stones(45.7%), like in Japan. So we make the research chart which is needed for analyzing the explosion accident, and then analyze these accidents systematically. using the investigation codes of the industrial accidents. After that, the FTA was performed on the accidents by flown stones. They result fromm non-observance of the safety rules, and lees knowledge of the safety and so on. Moreover several causes are combined and then the accidents are apt to happen. So according to the results of this study, for the protection of the explosion accidents, the specialized safety education is badly needed and the enough investigation of the places before the work along with the management for safety in working must be planned.

• Journal of Forest and Environmental Science
• /
• v.32 no.3
• /
• pp.311-322
• /
• 2016

Since forest trees form the basis of forest ecosystem, their prolong subsistence is crucial for various flora and fauna. The foremost challenges to sustain the forest ecosystem comprise of the declining forest tree population accompanied with structural changes due to afforestation and exploitation of forest area, environment changes, pests, pollution, and introgressive hybridization. For ex situ conservation approach, in vitro techniques encompass basic role for conserving tree genetic resources, predominantly where natural propagules like recalcitrant seed might not be appropriate for long-term conservation. The practice includes restricted growth techniques, conventional micropropagation, production and storage of synthetic seeds, and cryopreservation. Even though these practices have been applied chiefly to herbaceous species, but recently, woody species were also focused upon. Key conceptions, challenges and techniques for forest tree seed conservation are discussed briefly in this review with special emphasis on some successful cryopreservation approaches for long-term storage.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.28 no.10B
• /
• pp.876-890
• /
• 2003

This paper proposes a protocol for the reliableand QoS-aware multicast transport, which is called the Enhanced Communications Transport Protocol (ECTP). The ECTP has so far been developed and standardized in ITU-T SG17 and ISO/IEC JTC 1/SC 6. Differently from the conventional reliable multicast, as shownin the IETF RMT WG, the ECTP additionally provides several distinct features such as tight control of multicast session, tree-based error control, and QoS management. For the tight control of multicast connections, the sender is at the heart of one-to-many group communications, and it is responsible for overall connection management such as connection creation/termination, pause/resumption, and the join and leave operations. for tree-based reliability control, ECTP configures a hierarchical tree during connection creation. Error control is performed within each local group defined by a control tree, which was partly designed like the IETF TRACK approach. Each parent retransmits lost data in response to retransmission requests from its children. For QoS management, ECTP supports QoS negotiation for resource reservation, and it also provides QoS monitoring and maintenance operations. ECTP has been implemented and tested on Linux machine, along with Application Programming Interfaces based on Berkeley sockets. For basic testing of the ECTP functionality, we give some preliminary experimental results for performance comparison of ECTP and TCP unicast transports. In conclusion, we describe the status of ECTP experimentations over APAN/KOREN testbed networks

• Journal of the Korea Furniture Society
• /
• v.22 no.4
• /
• pp.299-307
• /
• 2011

This article aimed to provide objective and practical information on wood terms of making furniture focusing on the wood species that furniture designers and firms in Korea have used to create furniture from the traditional up to the modern times. Through the content analysis method with wood information from literature related to furniture at home and abroad, studios of making the traditional Korean furniture, domestic furniture firms, and the catalogues of Korean crafts council and Korea furniture society, the wood species of making furniture was studied in the terms showing the number of the species classified in needle leaf tree and broad leaf tree. As a result, the furniture wood terms were analyzed about 230 species including 200 broad leaf tree and 30 needle leaf tree. 74 out of 100 domestic species studied have been used from the traditional up to the modern time for creating the traditional Korean wood furniture. The 230 species were classified by such detailed uses as furniture mainly and the related small objects, interiors, architecture, exteriors, materials like plywood, toys, musical instrument, exercise equipment, household items, and so on. In addition, some of the terms were clarified such as Madika to Jelutong, Karin to Paudauk and Narra, Red sandalwood to Indian rose wood, and Cherry blossoms from home, the same family as Cherry from abroad but the different species, and so on.

• Journal of Electrical Engineering and Technology
• /
• v.8 no.4
• /
• pp.889-898
• /
• 2013

The shortest-path searching algorithm must not only find a global solution to the destination, but also solve a turn penalty problem (TPP) in an urban road transportation network (URTN). Although the Dijkstra algorithm (DA) as a representative node-based algorithm secures a global solution to the shortest path search (SPS) in the URTN by visiting all the possible paths to the destination, the DA does not solve the TPP and the slow execution speed problem (SEP) because it must search for the temporary minimum cost node. Potts and Oliver solved the TPP by modifying the visiting unit from a node to the link type of a tree-building algorithm like the DA. The Multi Tree Building Algorithm (MTBA), classified as a representative Link Based Algorithm (LBA), does not extricate the SEP because the MTBA must search many of the origin and destination links as well as the candidate links in order to find the SPS. In this paper, we propose a new Link-Based Single Tree Building Algorithm in order to reduce the SEP of the MTBA by applying the breaking rule to the LBA and also prove its usefulness by comparing the proposed with other algorithms such as the node-based DA and the link-based MTBA for the error rates and execution speeds.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2009.10a
• /
• pp.815-816
• /
• 2009

Owing to the development of computer technologies, to process data derived from various sensors is recently demanding. It is also increasing to demand the moving object based servies like the services of location based and mobile application services. That's why it is needed the processing of visualizing the services for education aspects. In this paper, we show the implemented results about $R^*$ tree algorithm to insert, delete and search a object in two dimension environment.

• International journal of advanced smart convergence
• /
• v.12 no.1
• /
• pp.92-100
• /
• 2023

Wireless communication technology is becoming increasingly prevalent in smart factories, but the rise in the number of wireless devices can lead to interference in the ISM band and obstacles like metal blocks within the factory can weaken communication signals, creating radio shadow areas that impede information exchange. Consequently, accurately determining the radio communication coverage range is crucial. To address this issue, a Radio Environment Map (REM) can be used to provide information about the radio environment in a specific area. In this paper, a technique for estimating an indoor REM usinga mobile robot and machine learning methods is introduced. The mobile robot first collects and processes data, including the Received Signal Strength Indicator (RSSI) and location estimation. This data is then used to implement the REM through machine learning regression algorithms such as Extra Tree Regressor, Random Forest Regressor, and Decision Tree Regressor. Furthermore, the numerical and visual performance of REM for each model can be assessed in terms of R2 and Root Mean Square Error (RMSE).

• Honam Mathematical Journal
• /
• v.39 no.4
• /
• pp.493-501
• /
• 2017

In this paper, we define and enumerate two tree-like hypergraph structures which we call them (d, k)-trees and d-trees, where $d{\geq}2$ and k > 0 are integers. These new definitions generalize traditional and HP-hypertrees.

• Fashion & Textile Research Journal
• /
• v.16 no.5
• /
• pp.698-705
• /
• 2014

This study classifies features of women's hair adornments with the functional and decorative aspects in the Three Kingdoms Period and analyses in regards to their contemporary social and cultural surroundings. First, the tree-shaped and Rod-like hairpins in the Three Kingdoms Period are not as similar as to the hairpins found in China or other northern countries. It is farming lives and the wood-worship religion established the wearing of high-bun hair styles and tree-shaped hairpins. Second, high-bun hair styles and -shaped hairpins were basic hair decorations during the Three Kingdoms Period. Common high-bun styles finally became one of the cultures that reflected the contemporary thinking. High-bun hair styles, not excessively-decorated, became harmonized with the costume beauty and later developed along with with various-shaped hairpins. Third, Buyao (made of metals and based on flower subjects)in the Three Kingdoms Period was a unique style not been seen in the Han and Wei-jin-nam-bei-chao Period. Flowers in Buyao of the of the Three Kingdoms Period show an elegant sway, which is not excessively-decorated that developed into unique features.

• Journal of the Korean Home Economics Association
• /
• v.33 no.3
• /
• pp.265-277
• /
• 1995

Shoos-in in Nara of Japan has two kinds of Priest's robe(Kasa : 袈裟) ; one is Jiksung Kasa(織成袈裟), the other Janap Kasa(刺納袈裟). The former is listed as the 'Jiksung Kasa of tree bark color in seven stripes' in the Treasures Record(珍寶帳) of objects dedicated by Empress Komyo on the 21st day of the 6th month 756 A.D. The warp threads are brown and the weft threads are in groups of two in two colors-dark blue, green yellow and red. The latter is the so called Janap Kasa, of tree bark colors in seven stripes, that was also dedicated by Empress Komyo, 'Ja' means to stitch, and 'Nap' means to sew. It is made of patches of silk of various color, placed overlapping one another in patterns the resemble a mountainous landscape. All are stitched together in a continous quilt-like manner with purple threads. Japan has been under the strong influence of Korea Buddhism during the Nara period. Acording to Nihonki(日本書紀) and Sokunihonki(續日本紀), from 668 to 769 A.D., Japan has bought numorous objects including Buddhist utensils such as priest's robes and banners from Korea. Also during the same period Japan has perchased many kinds of dyestuffs and paint. So we can be certain that priest’s robes were imported from Korea like many other objects of Shoso-in.