• Title/Summary/Keyword: 공사방법

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Evolution of Aviation Safety Regulations to cope with the concept of data-driven rulemaking - Safety Management System & Fatigue Risk Management System

  • Lee, Gun-Young
    • The Korean Journal of Air & Space Law and Policy
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    • v.33 no.2
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    • pp.345-366
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    • 2018
  • Article 37 of the International Convention on Civil Aviation requires that rules should be adopted to keep in compliance with international standards and recommended practices established by ICAO. As SARPs are revised annually, each ICAO Member State needs to reflect the new content in its national aviation Acts in a timely manner. In recent years, data-driven international standards have been developed because of the important roles of aviation safety data and information-based legislation in accident prevention based on human factors. The Safety Management System and crew Fatigue Risk Management Systems were reviewed as examples of the result of data-driven rulemaking. The safety management system was adopted in 2013 with the introduction of Annex 19 and Chapter 5 of the relevant manual describes safety data collection and analysis systems. Through analysis of safety data and information, decision makers can make informed data-driven decisions. The Republic of Korea introduced Safety Management System in accordance with Article 58 of the Aviation Safety Act for all airlines, maintenance companies, and airport corporations. To support the SMS, both mandatory reporting and voluntary safety reporting systems need to be in place. Up until now, the standard of administrative penal dispensation for violations of the safety management system has been very weak. Various regulations have been developed and implemented in the United States and Europe for the proper legislation of the safety management system. In the wake of the crash of the Colgan aircraft, the US Aviation Safety Committee recommended the US Federal Aviation Administration to establish a system that can identify and manage pilot fatigue hazards. In 2010, a notice of proposed rulemaking was issued by the Federal Aviation Administration and in 2011, the final rule was passed. The legislation was applied to help differentiate risk based on flight according to factors such as the pilot's duty starting time, the availability of the auxiliary crew, and the class of the rest facility. Numerous amounts data and information were analyzed during the rulemaking process, and reflected in the resultant regulations. A cost-benefit analysis, based on the data of the previous 10 year period, was conducted before the final legislation was reached and it was concluded that the cost benefits are positive. The Republic of Korea also currently has a clause on aviation safety legislation related to crew fatigue risk, where an airline can choose either to conform to the traditional flight time limitation standard or fatigue risk management system. In the United States, specifically for the purpose of data-driven rulemaking, the Airline Rulemaking Committee was formed, and operates in this capacity. Considering the advantageous results of the ARC in the US, and the D4S in Europe, this is a system that should definitely be introduced in Korea as well. A cost-benefit analysis is necessary, and can serve to strengthen the resulting legislation. In order to improve the effectiveness of data-based legislation, it is necessary to have reinforcement of experts and through them prepare a more detailed checklist of relevant variables.

Soil Washing Coupled with the Magnetic Separation to Remediate the Soil Contaminated with Metal Wastes and TPH (자력선별과 토양세척법을 연계하여 금속폐기물과 TPH로 복합 오염된 토양 동시 정화)

  • Han, Yikyeong;Lee, Minhee;Wang, Sookyun;Choi, Wonwoo
    • Economic and Environmental Geology
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    • v.52 no.1
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    • pp.1-12
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    • 2019
  • Batch experiments for the soil washing coupled with the magnetic separation process were performed to remediate the soil contaminated with metal and oil wastes. The soil was seriously contaminated by Zn and TPH (total petroleum hydrocarbon), of which concentrations were 1743.3 mg/kg and 3558.9 mg/kg, respectively, and initial concentrations of Zn, Pb, Cu, and TPH were higher than the 2nd SPWL (soil pollution warning limit: remediation goal). The soil washing with acidic solution was performed to remove heavy metals from the soil, but Pb and Zn concentration of the soil maintained higher than the 2nd SWPL even after the soil washing with acidic solution. The 2nd soil washing was repeated to increase the Pb and Zn removal efficiency and the Zn and Pb removal efficiencies additionally increased by only 8 % and 5 %, respectively, by the 2nd soil washing (> 2nd SPWL). The small particle separation from the soil was conducted to decrease the initial concentration of heavy metals and to increase the washing effectiveness before the soil washing and 4.1 % of the soil were separated as small particles (< 0.075 mm in diameter). The small particle separation lowered down Zn and Pb concentrations of soil to 1256.3 mg/kg (27.9 % decrease) and 325.8 mg/kg (56.3 % decrease). However, the Zn concentration of soil without small particles still was higher than the 2nd SPWL even after the soil washing, suggesting that the additional process is necessary to lower Zn concentration to below the 2nd SPWL after the treatment process. As an alternative process, the magnetic separation process was performed for the soil and 16.4 % of soil mass were removed, because the soil contamination was originated from unreasonable dumping of metal wastes. The Zn and Pb concentrations of soil were lowered down to 637.2 mg/kg (63.4 % decrease) and 139.6 mg/kg (81.5 % decrease) by the magnetic separation, which were much higher than the removal efficiency of the soil washing and the particle separation. The 1st soil washing after the magnetic separation lowered concentration of both TPH and heavy metals to below 2nd SPWL, suggesting that the soil washing conjugated with the magnetic separation can be applied for the heavy metal and TPH contaminated soil including high content of metal wastes.

Dynamic Changes of Urban Spatial Structure in Seoul: Focusing on a Relative Office Price Gradient (오피스 가격경사계수를 이용한 서울시 도시공간구조 변화 분석)

  • Ryu, Kang Min;Song, Ki Wook
    • Land and Housing Review
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    • v.12 no.3
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    • pp.11-26
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    • 2021
  • With the increasing demand for office space, there have been questions on how office rent distribution produces a change in the urban spatial structure in Seoul. The purpose of this paper is to investigate a relative price gradient and to present a time-series model that can quantitatively explain the dynamic changes in the urban spatial structure. The analysis was dealt with office rent above 3,306 m2 for the past 10 years from 1Q 2010 to 4Q 2019 within Seoul. A modified repeat sales model was employed. The main findings are briefly summarized as follows. First, according to the estimates of the office price gradient in the three major urban centers of Seoul, the CBD remained at a certain level with little change, while those in the GBD and the YBD continued to increase. This result reveals that the urban form of Seoul has shifted from monocentric to polycentric. This shows that the spatial distribution of companies has gradually accelerated decentralized concentration implying that the business networks have become significant. Second, contrary to small and medium-sized office buildings that have undertaken no change in the gradient, large office buildings have seen an increase in the gradient. The relative price gradients in small and medium-sized buildings were inversely proportional among the CBD, the GBD, and the YBD, implying their heterogeneous submarkets by office rent movements. Presumably, those differences in the submarkets were attributed to investment attraction, industrial competition, and the credit and preference of tenants. The findings are consistent with the hierarchical system identified in the Seoul 2030 Plan as well as the literature about Seoul's urban form. This research claims that the proposed method, based on the modified repeat sales model, is useful in understanding temporal dynamic changes. Moreover, the findings can provide implications for urban growth strategies under rapidly changing market conditions.

A Study on the Determinants of Demand for Visiting Department Stores Using Big Data (POS) (빅데이터(POS)를 활용한 백화점 방문수요 결정요인에 관한 연구)

  • Shin, Seong Youn;Park, Jung A
    • Land and Housing Review
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    • v.13 no.4
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    • pp.55-71
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    • 2022
  • Recently, the domestic department store industry is growing into a complex shopping cultural space, which is advanced and differentiated by changes in consumption patterns. In addition, competition is intensifying across 70 places operated by five large companies. This study investigates the determinants of the visits to department stores using the big data concept's automatic vehicle access system (pos) and proposes how to strengthen the competitiveness of the department store industry. We use a negative binomial regression test to predict the frequency of visits to 67 branches, except for three branches whose annual sales were incomplete due to the new opening in 2021. The results show that the demand for visiting department stores is positively associated with airport, terminal, and train stations, land areas, parking lots, VIP lounge numbers, luxury store ratio, F&B store numbers, non-commercial areas, and hotels. We suggest four strategies to enhance the competitiveness of domestic department stores. First, department store consumers have a high preference for luxury brands. Therefore, department stores need to form their own overseas buyer teams to discover and attract new luxury brands and attract customers who have a high demand for luxury brands. In addition, to attract consumers with high purchasing power and loyalty, it is necessary to provide more differentiated products and services for VIP customers than before. Second, it is desirable to focus on transportation hub areas such as train stations, airports, and terminals in Gyeonggi and Incheon. Third, department stores should attract tenants who can satisfy customers, given that key tenants are an important component of advanced shopping centers for department stores. Finally, the department store, a top-end shopping center, should be developed as a space with differentiated shopping, culture, dining out, and leisure services, such as "The Hyundai", which opened in 2021, to ensure future growth potential.

Mechanism of steel pipe reinforcement grouting based on tunnel field measurement results (터널 현장 계측결과를 통한 강관보강 그라우팅의 거동 메커니즘)

  • Shin, Hyunkang;Jung, Hyuksang;Lee, Yong-joo;Kim, Nag-young;Ko, Sungil
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.23 no.3
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    • pp.133-149
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    • 2021
  • This study aims to report the behavioral mechanism of steel pipe reinforcement grouting, which is being actively used to ensure the stability of the excavation surface during tunnel excavation, based on measurements taken at the actual site. After using a 12 m steel pipe attached with a shape displacement meter and a strain gauge to reinforce the actual tunnel surface, behavioral characteristics were identified by analyzing the measured deformation and stress of the steel pipe. Taking into account that the steel pipes were overlapped every 6 m, the measured data up to 7 m of excavation were used. In addition, the behavioral characteristics of the steel pipe reinforcement according to the difference in strength were also examined by applying steel pipes with different allowable stresses (SGT275 and SGT550). As a result of analyzing the behavior of steel pipes for 7 hours after the first excavation for 1 m and before proceeding with the next excavation, the stress redistribution due to the arching effect caused by the excavation relaxation load was observed. As excavation proceeded by 1 m, the excavated section exhibited the greatest deformation during excavation of 4 to 6 m due to the stress distribution of the three-dimensional relaxation load, and deformation and stress were generated in the steel pipe installed in the ground ahead of the tunnel face. As a result of comparing the behavior of SGT275 steel pipe (yield strength 275 MPa) and SGT550 steel pipe (yield strength 550 MPa), the difference in the amount of deformation was up to 18 times and the stress was up to 12 times; the stronger the steel pipe, the better it was at responding to the relaxation load. In this study, the behavior mechanism of steel pipe reinforcement grouting in response to the arching effect due to the relaxation load was identified based on the measured data during the actual tunnel excavation, and the results were reported.

An Evaluation of Allowable Bearing Capacity of Weathered Rock by Large-Scale Plate-Bearing Test and Numerical Analysis (대형평판재하시험 및 수치해석에 의한 풍화암 허용지지력 평가)

  • Hong, Seung-Hyeun
    • Journal of the Korean Geotechnical Society
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    • v.38 no.10
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    • pp.61-74
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    • 2022
  • Considering that the number of cases in which a structure foundation is located on weathered rock has been increasing recently, for adequate design bearing capacity of a foundation on weathered rock, allowable bearing capacities of such foundations in geotechnical investigation reports were studied. With reference to the study results, the allowable bearing capacity of a foundation on weathered rock was approximately 400-700 kN/m2, with a large variation, and was considered a conservative value. Because the allowable bearing capacity of the foundation ground is an important index in determining the foundation type in the early design stage, it can have a significant influence on the construction cost and period according to the initial decision. Thus, in this study, six large-scale plate-bearing tests were conducted on weathered rock, and the bearing capacity and settlement characteristics were analyzed. According to the test results, the bearing capacities from the six tests exceeded 1,500 kN/m2, and it shows that the results are similar with the one of bearing capacity formula by Pressuremeter tests when compared with the various bearing capacity formula. In addition, the elastic modulus determined by the inverse calculation of the load-settlement behavior from the large-scale plate-bearing tests was appropriate for applying the elastic modulus of the Pressuremeter tests. With consideration of the large-scale plate-bearing tests in this study and other results of plate-bearing tests on weathered rock in Korea, the allowable bearing capacity of weathered rock is evaluated to be over 1,000 kN/m2. However, because the settlement of the foundation increases as the foundation size increases, the allowable bearing capacity should be restrained by the allowable settlement criteria of an upper structure. Therefore, in this study, the anticipated foundation settlements along the foundation size and the thickness of weathered rocks have been evaluated by numerical analysis, and the foundation size and ground conditions, with an allowable bearing capacity of over 1,000 kN/m2, have been proposed as a table. These findings are considered useful in determining the foundation type in the early foundation design.

The Development and Application of the Officetel Price Index in Seoul Based on Transaction Data (실거래가를 이용한 서울시 오피스텔 가격지수 산정에 관한 연구)

  • Ryu, Kang Min;Song, Ki Wook
    • Land and Housing Review
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    • v.12 no.2
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    • pp.33-45
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    • 2021
  • Due to recent changes in government policy, officetels have received attention as alternative assets, along with the uplift of office and apartment prices in Seoul. However, the current officetel price indexes use small-size samples and, thus, there is a critique on their accuracy. They rely on valuation prices which lag the market trend and do not properly reflect the volatile nature of the property market, resulting in 'smoothing'. Therefore, the purpose of this paper is to create the officetel price index using transaction data. The data, provided by the Ministry of Land, Infrastructure and Transport from 2005 to 2020, includes sales prices and rental prices - Jeonsei and monthly rent (and their combinations). This study employed a repeat sales model for sales, jeonsei, and monthly rent indexes. It also contributes to improving conversion rates (between deposit and monthly rent) as a supplementary indicator. The main findings are as follows. First, the officetel price index and jeonsei index reached 132.5P and 163.9P, respectively, in Q4 2020 (1Q 2011=100.0P). However, the rent index was approximately below 100.0. Sales prices and jeonsei continued to rise due to high demand while monthly rent was largely unchanged due to vacancy risk. Second, the increase in the officetel sales price was lower than other housing types such as apartments and villas. Third, the employed approach has seen a potential to produce more reliable officetel price indexes reflecting high volatility compared to those indexes produced by other institutions, contributing to resolving 'smoothing'. As seen in the application in Seoul, this approach can enhance accuracy and, therefore, better assist market players to understand the market trend, which is much valuable under great uncertainties such as COVID-19 environments.

The Reinterpretation and its Prospect about Resentment Solution and Coexistence in The 4th Industrial Revolution Era (4차 산업혁명 시대에 있어서 해원상생의 재해석과 지평)

  • Kim, Bang-ryong
    • Journal of the Daesoon Academy of Sciences
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    • v.29
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    • pp.37-68
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    • 2017
  • This paper critically examines the role and function of religion prior to the full-out advent of the 4th industrial revolution. We can understand 'The vision of Daesoon Jinrihoe (大巡眞理會)' as a mission to foresee and create a prospective figure for a future society in the person of the Lord on High, Jeungsan (甑山) as a religious dimension. However, the existence ground of religion relies on giving positive meaning to the present time after reinterpreting religious doctrine to reflect changing realities. Jeungsan (甑山) said that the age to come is 'the age of the human majesty (人尊)'. This means that humans will take the lead and control the revolution of scientific technology to progress and benefit humanity. Problems such as 'human alienatio', 'increased polarization', and 'destruction of the environment' still arise and deepen because the motive of 'the Industrial Revolution' was built upon 'knowledge' within the context of a Knowledge-Based Society. Therefore, we can say that the role of religion will newly rise to the forefront in the era of the 4th industrial revolution. Consequently, religion should face matters squarely and suggest viable alternatives. This paper deals with reinterpreting the concept of 'the resolution of grievances for mutual beneficence (解冤相生)', one of the four teachings of Daesoon Jinrihoe, within the context of the coming era of the 4th industrial revolution. My research is divided into the following three parts: First, I determined the teachings of Daesoon Jinrihoe and the original meaning of 'the resolution of grievances for mutual beneficence', and then I disclosed the way we can reinterpret the general meaning of this concept for application in the ear of the 4th industrial revolution. Second, from the perspective of the religious dimension, I inquired into factors regarding alienation and conflict in the era of the 4th industrial revolution. I focused on human alienation from labor, identity confusion, potential conflicts between humans and post-humans, and the characteristics of the 4th industrial revolution. Third, I examined potential cures for alienation and conflict through the principle of the resolution of grievances for mutual beneficence. I tried to enlarge the interpretive prospects of Daesoon's main teaching in light of the era of the 4th industrial revolution through a new interpretation and application that employs the concept of 'the resolution of grievances for mutual beneficence (解冤相生)' in order to cure the alienation and conflict.

The Knowledge Transfer Network and Performance of Chinese Subsidiary in Korean MNCs : Focusing on Roles of Absorptive Capacity and Entry Mode (한국 다국적기업의 중국 자회사의 지식이전, 네트워크와 경영성과에 관한 연구 - 흡수능력과 진입방식의 역할을 중심으로 -)

  • Yoon, Ki-Chang
    • Korea Trade Review
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    • v.41 no.5
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    • pp.325-351
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    • 2016
  • This study empirically investigated the relationship among knowledge transfer, network(firm network and government network) and performance Korean MNCs' subsidiaries in terms of absorptive capacity and entry mode roles in China. For this, absorptive capacity was established as an independent variable, mediating variable, and moderating variable. And the entry mode was divided into single investment and joint venture and set to the moderating variable. Data for the analysis of actual proof was randomly selected from the companies which was established more than 3 years before KOTRA 'The overseas expansion Korean company directory (2014)'. Questionnaires to 138 Chinese subsidiaries of Korean MNCs were collected by FAX and E-mail. AMOS was utilized and collected data investigated the role of the absorption capacity and entry mode as the covariance structure analysis. The empirical analysis showed that absorption capacity has a direct influence on management performance as an independent variable with the network (firm network and government network). It only has a partial mediating role between enterprise networks and management performance, and no meaningful result was gained as its moderationg role bewteen the exogenous variable and management performance. And in terms of Korean companies' moderating role in entering China, they have a moderating role between government network, absorption capacity and management performance, but did not show a statistically significant result between knowledge transfer, enterprise network and management performance. Absorption capacity, as the variable affecting overseas subsidiary's management performance, should not be considered a mediating or moderating variable, but an independent variable. Since the joint venture is showing higher performance than single investment when going into the Chinese market, implication is provided for options in overseas expansion. But this research has the limitation in generalization because it is aiming at the subsidiaries of the Korean company investing in China. Therefore, it is more desirable in the future to conduct a study of the subsidiary of the Korean company entering several countries. It also has limitations in generalization, because the research was conducted using a limited number of variables, despite there are various factors affecting the management performance of Chinese subsidiaries.

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Basic Study on Historical Repair Techniques for Landscape Architectural Facilities - Focusing on Government-managed Spaces in Joseon Dynasty - (전통조경 시설물의 역사적 수리기법에 관한 기초연구 - 조선시대 관영공간을 중심으로 -)

  • Kim, Min-Seon;Oh, Jun-Young
    • Journal of the Korean Institute of Traditional Landscape Architecture
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    • v.41 no.4
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    • pp.8-20
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    • 2023
  • Although the landscape architectural facilities need to be repaired according to historical and authentic techniques, the repair criteria of the standard specification for repairing cultural heritages still remain at a theoretical level, and there are little research analyzing detailed techniques from specific cases. This study discussed the repair techniques based on historical facts, around terraced flower beds, ponds, waterways and pavement in the government-managed spaces in the Joseon Dynasty. It analyzed the materials and finish of stone wall elements, the structural reinforcement and backfill materials, and topsoil surface protection measures, and drew out stones for foundation reinforcement, plastering material for agglutination, and stone processing techniques for the terraced flower beds. It examined the materials and structures of the rock revetment, foundation reinforcement and waterproofing techniques and drew out the outstanding characteristics of the foundation work, the recycle of used elements and the management of water quality, for the ponds. It primarily investigated the materials, foundation reinforcement and waterproofing techniques and discovered the repair techniques such as cover stone finishing methods, foundation and backfill materials, and flow reduction methods, for the waterways. Finally, it provided actual cases of the foundation composition, auxiliary materials and tools, and the use of cyperaceae and highlighted the existence of professional craftsmen called Bangjeonjang(方磚匠), for the pavement. This study is expected to be a staring point for discovering the repair techniques for landscape architectural facilities and used as basic data for revising specifications in the future.