• Journal of the Korean GEO-environmental Society
• /
• v.15 no.9
• /
• pp.19-28
• /
• 2014

Recently, the proportion of long tunnel has increased for efficient use of land due to limited land area, driving convenience and high speed. RMR and Q-System of empirical methods has been mainly used for tunnel support design in domestic. Although shotcrete is the key to NATM tunnel, the related studies are insufficient. So, steel fiber reinforced shotcrete is applied to II~V grade rocks on domestic and foreign applications. And same amount of shotcrete is equally applied to tunnel roof and wall regardless of the applied rock load. Shotcrete is applied excessively rather than the original proposed value of RMR and Q-System. Thus, this study is to reevaluate the application part of plain shotcrete and steel fiber reinforced shotcrete of tunnel in Daebo granite, and to propose the reasonable application method of steel fiber reinforced shotcrete. Field test and numerical back analysis using measurements were performed to verify stability. According to results, if RMR values are the upper class in the III grade, it can be designed in accordance with upper grade. In addition, if rock condition is good as a mountain tunnel in Daebo granite, it can be applied for plain shotcrete to III grade rocks because there is also no stability problems. And although steel fiber reinforced shotcrete is applied only crown of the tunnel in IV grade rocks, it is possible to secure stability for falling rock by key-block.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.2
• /
• pp.501-510
• /
• 2016

Because hotels contain the cultural and artistic information of an era and plays a role as an iconic building to experience the unique regional culture, they are more than just a building. In recent years, as Jeju is emerging as a popular tourist city, a multi-functional and systematic plan for hotels is needed. Therefore, this study provides basic design data for hotel construction in the future by analyzing the public space of the luxury tourist hotels on Seogwipo-si. The public space of hotels, divided into service, food and beverage, banquet, leisure and convenience space, are categorized in terms of the cross combination type, entrance space form, plan type, unit space form to understand their relativity in the public space of hotels. This study reviewed the hotel construction based on the reference and literature, and, visited the sites to determine the current general status of hotels and then analyzed the architectural planning factors and spatial composition types.

• Journal of Korean Society on Water Environment
• /
• v.22 no.2
• /
• pp.321-327
• /
• 2006

This interlaboratory study was designed to evaluate protozoan test methods in water and to predict the major causes of deviation of the methods. Each of four laboratories with previous experience of protozoa analysis in water participated, and met the initial performance criteria of EPA 1623 method provided. The protozoan analysis procedure consists of filtrations, concentration, immunomagnetic separation, dyeing (staining) and counting with observation. We tested three different filtration equipments: capsule filter for 10 L of surface water, and high volume (HV) capsule filter and membrane filter for 100 L of finished water. When the recovery of each step of the procedure was evaluated with EasySeed, the commercial stock of each 100 Cryptosporidium and Giardia, immunomagnetic separation and filtration step were the most crucial steps affecting the stability of the recovery, especially for Cryptosporidium. There was no significant difference of recovery among the filtration methods. Recovery of protozoa from source water were evaluated with spiked EasySeed as matrix tests. The recoveries of Giardia increased significantly in the matrix tests compared those in the deionized water. We also applied red stained mixture stocks of Cryptosporidium and Giardia called ColorSeed as internal standards of water sample tests. The recoveries of both EasySeed and ColorSeed in samples tested were within the range of the criteria, however, the Giardia recoveries using ColorSeed decreased significantly. Further optimization study with ColorSeed will be necessary, considering the convenience of using the internal standard without additional sample analysis. The significant factors of the recovery variation were identified as the differences of laboratories as well as water quality and type of the stock for spiking. The results of this study emphasize the importance of the quality assurance program for protozoan analysis lab in water.

• Korean Journal of Construction Engineering and Management
• /
• v.10 no.5
• /
• pp.123-134
• /
• 2009

Since 1970s, urethane waterproofing method is broadly used in rooftops, underground spaces, and sports stadium for its outstanding ultraviolet blockage, watertightness, and elasticity. However, development of slippage-resistance and endurance, improvement of function considering convenience and visually pleasing of users, urethane waterproofing method is necessary, since rooftops and underground spaces have slippage and external force risks. Therefore, many improved waterproofing methods are being developed and, recently, embo-thane waterproofing method, which applies embo-spray coating system, has been developed. This paper explains exposure, nonexposure, and floor-material of embo-thane waterproofing method, and then perform experimental study for comparison with urethane waterproofing method about tensile strength, coefficient of expansion, performance of bond, anti-abrasion, and slippage-resistance. In addition, the performance index was presented for the superiority of embo-thane waterproofing method compared to urethane by setting up evaluation criteria considering not only physical performance but also design side of embo-thane waterproofing method, and Value Analysis applying AHP. Also for an assessment considering uncertain result, Monte Carlo Simulation Method was used to operate reliability analysis through statistic approach method.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.10
• /
• pp.678-684
• /
• 2016

The detection of an underwater work space boundary is very important when an underwater construction is carried out using seabed type underwater equipment, such as underwater machines for rubble mound leveling, because it can induce industrial disasters. Therefore, divers are needed to mark the underwater work space boundary. A nylon rope is used to improve the convenience during an underwater diver's work. The results showed that the work space boundary can be detected using a sonar system. Using these results, an efficient method to detect the underwater work space boundary can be obtained when an underwater construction is carried out using seabed type underwater equipment.

• The Journal of the Korea Contents Association
• /
• v.19 no.10
• /
• pp.217-225
• /
• 2019

National research and development(R&D) information is information generated in the process of performing R&D based on programs and projects issued by national government departments, and includes information from various research fields as ordered by various departments. Therefore, for efficient R&D information retrieval, it is necessary to build a national R&D terminology dictionary that can reflect the characteristics of such national R&D information. In this study, we propose a method for constructing a national R&D terminology dictionary by applying the classification of science and technology standards used to specify the research field in national R&D information. We will discuss the structural characteristics of national R&D project information and the usefulness of the project keyword, and explain the status of national R&D information by the National Standard Science and Technology Classification(NSSTC) Codes and the characteristics of the national R&D terminologies. Based on this, a method for building a national R&D terminology dictionary is defined in terms of the type and structure of the terminology dictionary, preliminary construction procedures, and refining rules. The national R&D terminology dictionary built on the basis of this study can be used in various ways such as expansion of search terms using Korean-English equivalent words and synonyms when searching national R&D information, clarifying the scope of search using NSSTC, and providing user convenience functions using term explanation information.

• Korean Journal of Heritage: History & Science
• /
• v.34
• /
• pp.222-267
• /
• 2001

The purpose of this document is to explain the revisions of the Protection of Cultural Properties Act and its sub-laws which have been mad from Jan. 1999 to Sep. 2001. The Protection of Cultural Properties Act and its sub-laws have been revised three times from 1999 to 2001, before and after the Office of Cultural Properties was raised to Cultural Properties Administration on May 24, 1999. The main points of the revisions are as follows. First of all, the role of the local autonomous entities has been increased. The governor of the local autonomous entities is entitled to announce administrative orders related to the preservation of State-designated Cultural Properties. Also, the local autonomous entities has the authorities to examine whether the construction work which will be made in the outer boundaries, which is provided by regulations, of the protected area of the cultural properties might have any effect on preservation of cultural properties or not. Second, preventive actions to protect the cultural properties have been strengthened. If the scale of construction work is more than some scale, the preliminary survey of the surface of the earth to confirm the existence of buried cultural properties and their distribution is obligated. One who is promoting the development plan more than some scale must discuss the plan with the Administrator of Cultural Properties Administration in the process of planning. These actions would be effective to prevent the cultural properties from being damaged because of the development. Third, relaxation of the restrictions has been proceeded. On the basis of regulations which specify the actions to affect the preservation of cultural properties, negative system that does not limit the actions which are not specified in the regulations is introduced. The appropriateness of both protected structure and area should be regularly reviewed and adjusted. Also, most of the restrictions which was made only for administrative convenience and over-regulated the people's living have been revised. Finally, the number of cultural properties to be protected has been increased. Besides the State-designated Cultural Properties, the other cultural properties which are worthy to be protected as City-or-Province-designated Cultural Properties can be designated provisionally and protected. The system of registration and maintenance of the buildings and facilities which are not designated as the Modern Cultural Heritages is established. The penalty for damaging and stealing the cultural Properties which are not designated to be protected was strengthened. Even a dead natural monument can be acknowledged as an natural monument and it is limited to make a specimen or stuffing of the dead natural monument. All of these actions are fit to the high level of understanding of the public about the cultural properties and as the result of these actions, the number of cultural properties to be preserved has been increased. To sum up, the directions of revisions of the Protection of Cultural Properties Act and its sub­laws which have been made from Jan. 1999 to Sep. 2001. are the localization of the protection of the cultural properties, the strengthening of protective actions, the relaxation of various regulations and the increasing of the number fo the protected cultural properties. Also, various problems raised in the processes of implementations of the laws have been reviewed and revised.

• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.34 no.4
• /
• pp.255-262
• /
• 2021

In this study, a jointless bridge that integrates the superstructure and abutment without installing an expansion joint was analyzed. An example of a jointless bridge that has been introduced in Korea since 2009. Owing to the short period of use and lack of experience in design, construction, and maintenance, there is insufficient information regarding the long-term behavior of jointless bridges. When analyzing numerous bridges, the numerical analysis model must maintain the numerical values used and ensure the convenience of model construction. In this study, sensitivity analysis was performed to select a numerical model for various types of jointless bridges using commercial finite element programs, MIDAS Civil and ABAQUS 2018. According to a solid element-based model, we analyzed the mean and maximum relative errors between structural models. Consequently, it was found that the beam element-based model exhibits a significantly small relative error in comparison to the shell element, where a relatively large error was recorded. Therefore, the optimal numerical analysis model, a practical model that maintains the similarity and precision of the displacement shape cause by relative error, was judged to be the most suitable for jointless bridges based on the shell element.

• Smart Media Journal
• /
• v.11 no.11
• /
• pp.49-62
• /
• 2022

Recently, with the development of Smart City Solutions such as Big data, AI, IoT, Autonomous driving, and Digital twins around the world, the proliferation of various smart devices and social media, and the record of the deeds that people have left everywhere, the construction of Smart Cities using the "Big Data" environment in which so much information and data is produced that it is impossible to gauge the scale is actively underway. The Purpose of this study is to construct an objective and systematic analysis Model based on Big Data to improve the transportation convenience of citizens and formulate efficient policies in Urban Information and Public Transportation accessibility in sustainable Smart Cities following the 4th Industrial Revolution. It is also to derive the methodology of developing a Big Data-Based public transport accessibility and policy management Platform using a sustainable Urban Public DB and a Private DB. To this end, Detailed Living Areas made a division and the accessibility of basic living amenities of Gwangju Metropolitan City, and the Public Transportation system based on Big Data were analyzed. As a result, it was Proposed to construct a Big Data-based Urban Information and Public Transportation accessibility Platform, such as 1) Using Big Data for public transportation network evaluation, 2) Supporting Transportation means/service decision-making based on Big Data, 3) Providing urban traffic network monitoring services, and 4) Analyzing parking demand sources and providing improvement measures.

• Journal of the Korean Institute of Gas
• /
• v.27 no.2
• /
• pp.1-6
• /
• 2023

PE piping, which has advantages in terms of construction convenience and economy, is widely used for underground burial in the domestic urban gas field. These PE pipes use squeeze-off in many sites to block gas flow during maintenance and repair work. Squeeze-off refers to a method of compressing a PE pipe to block fluid flow, and damage may occur due to the nature of construction in which the pipe is deformed by physical force. In order to prevent damage to PE pipes due to squeeze-off, the main points to be reflected in the squeeze-off operation procedures such as proper compression range, use pressure, and diameter were derived through damage assessment and confidential test according to the compression rate. The compression experiment for PE pipe damage assessment was conducted while changing the compression rate (20%~40%), the pressure of use (2.8 kPa, 25 kPa, 70 kPa), and the pipe diameters (63 mm, 90 mm, 110 mm). As a result of damage assessment according to the compression rate, damage occurred in pipes with compression rates of 45%(110mm) and 73%(63mm), which are for analyzing the effect of excessive compression. In addition, the leakage test was conducted using Ar(argon) during the squeeze-off, and as a result of the experiment, leakage occurred under the conditions of 70kPa and 110mm of pipe. As a result of this study, it was confirmed that squeeze-off for airtightness should be carried out in pipes within a range not exceeding 25 kPa and 90 mm pipes, and the appropriate compression rate to prevent damage to PE pipes is 30%.