• Title/Summary/Keyword: Critical path

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The Improvement of Curtain Wall Design Process using Value Stream Mapping Tools (VSM기법을 활용한 커튼월 공사의 설계 프로세스 개선)

  • Kim, Chang-Duk;Lee, Sang-Hyuk
    • Korean Journal of Construction Engineering and Management
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    • v.7 no.5
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    • pp.128-137
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    • 2006
  • This paper is to develop curtain wall process life-cycle system in high-rise buildings in order to establish effective cooperation communication channels among the diverse constituents. This paper is to provide a base toward a curtain wall life-cycle management system to support decision making and the effective flow in light of information and materials. The four objectives of the research are 1) the analysis of the current curtain wall life-cycle process, 2) the analysis and development of the curtain wall design process As-Is model, and 3) the Muda analysis of the design process As-Is model and the suggestion of the improvements, 4) the development of curtain wall design To-Be model and comparative analysis of the improvement in terms of value streams. This research indicates the wastes decrease (or the values increase) from 6.7% up to 100% in different decision criteria through the improvement by the comparative analysis between the As-ls and To-Be curtain wall design process. This research suggests the potential improvement by VSM and a curtain wall life-cycle management system in curtain wall construction for diverse constituents be significant.

A study on the economical analysis of non-supporting form in basement wall cases (지하옹벽 무지주 거푸집 사례의 경제성 분석에 관한 연구)

  • Kim, Jae-Yeob;Kim, Gwang-Hee;Lee, Sang-Woo;Sohn, Young-Jin
    • Journal of the Korea Institute of Building Construction
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    • v.9 no.4
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    • pp.111-117
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    • 2009
  • Considering the entire critical path, underground works in construction projects occupy a large part of the total construction period, as well as a large part of the construction costs. Particularly in the downtown area, the scale of underground work has been increasing every year. Currently, underground retaining walls, which are built at construction sites, require many skilled workers, and the works are being undertaken by means of the Euroform+Soldier system, which is quite disadvantageous in terms of the construction period. In order to complement this, forms made of new materials and new construction methods have been developed. Now more than eyer, the shortening of construction periods and the reduction of construction costs is required. Considering this, in this study, the researcher has tried to compare the Euroform+Soldier system, which has been the system most frequently used on construction sites, to the non-supporting form system, which has been used on the sites of civil engineering work. The results of the research revealed that although the Euroform+Soldier system was advantageous from the perspective of material costs, it was disadvantageous in terms of labor costs. It is thought that an additional study on a method for reducing the material costs is required, so as to revitalize the application of non-supporting forms to the construction site.

Efficiency Analysis for RFID-based Curtain Wall of unit Type Construction (RFID 기술 적용에 따른 유닛타입 커튼월 공사의 효율성 분석)

  • Kang, Hyun-Koo;Ha, Young-Seo;Lim, Chul-Woo;Kim, Chang-Duk;Yu, Jung-Ho
    • Korean Journal of Construction Engineering and Management
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    • v.9 no.3
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    • pp.206-213
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    • 2008
  • Due to the following reasons, the management of curtain wall parts and material is very Important. Firstly, curtain wall work is one of the main works in High-rise building construction for it takes about $10{\sim}15%$ of the total construction cost. Secondly, the whole process of curtain wall work including manu acture, delivery, storage, installation and maintenance is very complicated and sometimes more than 30 companies involve in the process. Thus there are many control points for curtain wall units. Thirdly, there are not enough space on site for material storage and this situation is more serious for sites in urban area. The purpose of this research is to validate an information systems using RFID technology that is developed to manage the curtain wall units following the process of curtain wall work. For the validation, the cycle times of curtain wall work before and a ter the system was used. The results show that using the systems shorten the cycle time of the curtain wall work. Thus it is concluded that the system can increase the efficiency of managing curtain wall work.

User Experience (UX) Analysis of Advertising Platform Mobile Applications for Culture and Arts Content: Critical case study based on the UX Honeycomb model (문화예술 광고 플랫폼 앱의 사용자 경험(UX) 연구: 허니콤 모델을 통한 비판적 사례분석)

  • An, Hye-Jin;Lee, Seung-Ha
    • The Journal of the Korea Contents Association
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    • v.22 no.9
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    • pp.1-18
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    • 2022
  • This study critically analyzed the user experience (UX) of mobile applications, focusing on the advertising platforms of mobile applications for culture and arts content. This study aims to examine the direction for growth of the related mobile applications and propose alternative approaches to improve usability. In this study, a mobile app named 'Moviepre' was selected, and a heuristic evaluation was performed for in-depth exploration. For the selected case, the UX Honeycomb model was reconstructed to analyze useful, usable, desirable, findable, accessible, and credible elements of the case. First, since the users' preference for the price factor did not show a significant correlation with the usefulness of the content and the interface, it is necessary to make sure that the mobile application has unique values to gain a competitive advantage in the market. Second, by adopting customer path stages for analysis, the result indicated that users continuously interact with the service from the first moment they are aware of the mobile application. Third, if the user feels uncomfortable, it is likely that these factors hinder the establishment of a long-term relationship between the users and the mobile application. Finally, brand identity should be clearly established, and brand image strategy needs to be developed to satisfy users' expectations that high-quality culture and arts content will be available through the mobile application.

A Quantitative Study of the Effects of a Price Collar in the Korea Emissions Trading System on Emissions and Costs (배출권거래제 가격상하한제가 배출량 및 감축비용에 미치는 영향에 대한 정량적 연구)

  • Bae, Kyungeun;Yoo, Taejoung;Ahn, Young-Hwan
    • Environmental and Resource Economics Review
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    • v.31 no.2
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    • pp.261-290
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    • 2022
  • Although market stabilization measures have been triggered in the K-ETS, carbon price is still under uncertainty. Considering Korea's 2030 enhanced reduction target announced in October 2021, it is crucial to have practical stabilization measures to appropriately deal with price uncertainty. This study examines the quantitative effects of a price collar, which is considered as a means of alleviating price uncertainty, on expected cumulative emissions and abatement costs. There are three main scenarios: carbon tax, emissions trading system, and emissions trading system with a price collar. Monte Carlo simulation was conducted to reflect uncertainty in emission. There are several results as follows: 1) In a price collar, domestic emission target is likely to be achieved with a lower expected abatement cost than other scenarios. In addition, there is a small amount of excess emissions in this research and it would be not critical(0.1% excess than target); 2) Prohibiting banking increases the expected abatement cost. This is because firms can not intertemporally reallocate allowances to match the firm's optimal emissions path; 3) With the adoption of a price collar, government's net revenue can be positive even if the government's purchase volume of emissions allowances is more than sales volume. This is because the government sells them at price ceiling and purchases them at price floor.

Cluster-based Delay-adaptive Sensor Scheduling for Energy-saving in Wireless Sensor Networks (센서네트워크에서 클러스터기반의 에너지 효율형 센서 스케쥴링 연구)

  • Choi, Wook;Lee, Yong;Chung, Yoo-Jin
    • Journal of the Korea Society for Simulation
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    • v.18 no.3
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    • pp.47-59
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    • 2009
  • Due to the application-specific nature of wireless sensor networks, the sensitivity to such a requirement as data reporting latency may vary depending on the type of applications, thus requiring application-specific algorithm and protocol design paradigms which help us to maximize energy conservation and thus the network lifetime. In this paper, we propose a novel delay-adaptive sensor scheduling scheme for energy-saving data gathering which is based on a two phase clustering (TPC). The ultimate goal is to extend the network lifetime by providing sensors with high adaptability to the application-dependent and time-varying delay requirements. The TPC requests sensors to construct two types of links: direct and relay links. The direct links are used for control and forwarding time critical sensed data. On the other hand, the relay links are used only for data forwarding based on the user delay constraints, thus allowing the sensors to opportunistically use the most energy-saving links and forming a multi-hop path. Simulation results demonstrate that cluster-based delay-adaptive data gathering strategy (CD-DGS) saves a significant amount of energy for dense sensor networks by adapting to the user delay constraints.

The Study on the meaning of laughter in Korean Mask Play (민속극에서 웃음의 의미 연구 - 영남지역 민속극을 중심으로)

  • Sim, SangGyo
    • (The) Research of the performance art and culture
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    • no.42
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    • pp.291-319
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    • 2021
  • In this paper, I looked for the parts where laughter appeared in the Mundoong, Yangban, Yeongno, and Grandfather and Grandmother of Tongyeong Ogwangdae and Dongrae Yaryu, and investigated the meaning of those parts. Laughter in mask play has made him more tolerant of human injustice and foolishness. I softened the critical content and naturally revealed what I thought should be hidden. Through a short and noisy plot, the opposing forces, the inner conflict of the Mundoong, Yangban, Yeongno, and Grandfather and Grandmother were shown in a realistic and realistic way. The worldview that creates the structure of realism is typically skeptical and ironic, and the worldview that creates the comical structure related to laughter aims for the ultimate emergence of a new order based on unity and harmony. Masking is thought to be a work in the stage of moving from the latter to the former. Therefore, it is judged that laughter in mask play served as an important medium for Korean art thought to have a realist view of the world. This is because various expression methods that induce laughter are working to reveal negativity, reveal the illusion of contemporary values, and naturally expose restraint and taboo suppression. In laughter, there is a path that transforms perception by fusing several elements. There was realism at the end of the pathway to new perception.

On the Evolution of Hong Kong's Nativism and Its Public Law Solutions (论香港本土主义的流变及其公法应对)

  • Man, Lai Pui;Yinhao, Tan
    • Analyses & Alternatives
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    • v.3 no.1
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    • pp.93-133
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    • 2019
  • Throughout history, there are three clues of dualistic structures for the development of Hong Kong's nativism. First, inward attribution and outward lookingare two paths to the formation of Hong Kong's nativism. In the dualistic framework of "self-others", nativism is formed. The formation path of "outward looking"can be seen everywhere in the construction history of Hong Kong's nativism. It is under the reflection of "two mirrors" with Britain and Chinese mainland that Hong Kong people acquire the concept of "Hong Kong's nativism". Second, there are two aspects of Hong Kong's nativism: economic and cultural aspect and political aspect. With the gradual development of Hong Kong's history, these two aspects come into being and are closely bound up, thus constituting Hong Kong's nativism today. The third clue is the most critical one. The subjectivity of colonization and decolonization are two different forms of Hong Kong people's subjectivity. These three clues run through the whole process of the construction of Hong Kong nativism, and are carried out in three stages of development: "Origin (1960s-1970s): Preliminary Construction of Hong Kong's Nativism", "Development of Hong Kong's Nativism (1980s-1997): Awakening of Political Aspect" and "Formation and Alienation of Hong Kong's Nativism (1997-present): Deformed "decolonization". Along the evolution of Hong Kong's nativism, with the disintegration of colonialism, Hong Kong people have gradually transited from the subjectivity of colonization to the subjectivity of decolonization, but the process of "decolonization" has not been completed up to now.When nativism loses its native complex from the perspective of "inherent in China", and further develops into the "separatism" of anti-constitutional system and anti-national continuity and unity, it will challenge the stability of the relationship between the central government and the Special Administrative Region under the "one country, two systems". At the same time, it will have a greater impact on the political structure and the rule of law system of Hong Kong, and trigger a series of public law problems that need to be solved urgently. In this regard, on the one hand, we should re-clarify the relationship between the central government and the region under the "one country, two systems" in light of the new situation of democratic political development in Hong Kong, and improve Hong Kong's governance mechanism on the basis of the constitution and the basic law; on the other hand, we should actively learn from the German defensive democracy system to systematically interpret, integrate and apply Hong Kong's existing legal resources so as to effectively curb the development of local separatist forces.

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Philosophical Counseling and Feminist Counseling (철학상담과 여성주의상담)

  • Nho, Soung-Suk
    • Women's Studies Review
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    • v.26 no.1
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    • pp.3-39
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    • 2009
  • Philosophical counseling, established by Achenbach in 1981, began as "philosophical practice" and emerged only recently as a new field of philosophy in its own right. It attempts, by recasting the philosopher as a counselor, to bring philosophy back from academia and recover the ancient notion of "doing philosophy," in a real-life context. Furthermore, it allows clients who are at a critical moment in their life a chance to revive their authentic selves and empowers them to pursue their own path. By engaging with philosophical counseling, clients are more likely to realize their hopes for their lives by examining their lives thoroughly and facing them anew. This paper first attempts to investigate philosophical counseling services for Korean women and to outline a new model of counseling based on the combination of two models of counseling, philosophical counseling and feminist counseling. In the second chapter, it seeks to introduce the history and characteristics of philosophical counseling and in the third chapter, the history and characteristics of feminist counseling are investigated, focusing on a counseling-activity entitled "Telephone for Women." Finally, in the fourth chapter, a comparative study is made by identifying the common aspects of each counseling type, in order to promote the shared outlooks of both counseling models. Although these two models of counseling emerged from different historical, social, and cultural contexts, they were founded according to four common beliefs, which are as follows: first, a focus on the importance of "practice," second, the establishment of an equal relationship between the counselor and the client, third, the importance of counselors listening attentively to the client and opening themselves up, fourth, the encouragement of clients becoming truly themselves and self-educated. Therefore, the writer believes that these two models of counseling are both aiming at the realization of an authentic "human life." It is hoped that philosophical counseling will give Korean women an opportunity to maintain a dialogue that will improve their "well-being" in the future.

Utilization of EPRI ChemWorks tools for PWR shutdown chemistry evolution modeling

  • Jinsoo Choi;Cho-Rong Kim;Yong-Sang Cho;Hyuk-chul Kwon;Kyu-Min Song
    • Nuclear Engineering and Technology
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    • v.55 no.10
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    • pp.3543-3548
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    • 2023
  • Shutdown chemistry evolution is performed in nuclear power plants at each refueling outage (RFO) to establish safe conditions to open system and minimize inventory of corrosion products in the reactor coolant system (RCS). After hydrogen peroxide is added to RCS during shutdown chemistry evolution, corrosion products are released and are removed by filters and ion exchange resins in the chemical volume control system (CVCS). Shutdown chemistry evolution including RCS clean-up time to remove released corrosion products impacts the critical path schedule during RFOs. The estimation of clean-up time prior to RFO can provide more reliable actions for RCS clean-up operations and transients to operators during shutdown chemistry. Electric Power Research Institute (EPRI) shutdown calculator (SDC) enables to provide clean-up time by Co-58 peak activity through operational data from nuclear power plants (NPPs). In this study, we have investigated the results of EPRI SDC by shutdown chemistry data of Co-58 activity using NPP data from previous cycles and modeled the estimated clean-up time by EPRI SDC using average Co-58 activity of the NPP. We selected two RFO data from the NPP to evaluate EPRI SDC results using the purification time to reach to 1.3 mCi/cc of Co-58 after hydrogen peroxide addition. Comparing two RFO data, the similar purification time between actual and computed data by EPRI SDC, 0.92 and 1.74 h respectively, was observed with the deviation of 3.7-7.2%. As the modeling the estimated clean-up time, we calculated average Co-58 peak concentration for normal cycles after cycle 10 and applied two-sigma (2σ, 95.4%) for predicted Co-58 peak concentration as upper and lower values compared to the average data. For the verification of modeling, shutdown chemistry data for RFO 17 was used. Predicted RCS clean-up time with lower and upper values was between 21.05 and 27.58 h, and clean-up time for RFO 17 was 24.75 h, within the predicted time band. Therefore, our calculated modeling band was validated. This approach can be identified that the advantage of the modeling for clean-up time with SDC is that the primary prediction of shutdown chemistry plans can be performed more reliably during shutdown chemistry. This research can contribute to improving the efficiency and safety of shutdown chemistry evolution in nuclear power plants.