• Journal of Construction Engineering and Project Management
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• v.3 no.3
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• pp.10-16
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• 2013

The annual expenditure on diesel oil and heavy oil in the construction sector is the second largest among all industrial sectors. According to the greenhouse reduction scheme of Korean Government, construction sector targeted 7.1% reduction by 2020. Although this target is not higher than other industrial sectors, it is not easy to achieve the reduction target without radical advance in technology, which cannot be expected to happen soon, considering the conservative characteristics of construction industry. Most researches on environmental issues focus on the issues related to energy saving matters during material production stage or maintenance stage, such as heating and insulation, and few deal with the issues directly related to the energy use in the construction sites. This research regards the operation of equipment for the on-site construction processes as a system and attempts to model the energy use processes related to the activities in construction sites, and provides simulation results of earth excavation and hauling processes. The result of this research is expected to aid construction planners estimating the time-based patterns of energy use and assessing greenhouse gas emission and to help selecting more energy efficient alternatives at the planning stage.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.58 no.3
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• pp.214-222
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• 2022

This study calculated the on-site measurement (Tier 4) of greenhouse gases emitted during the production stage of major fishing periods that utilize set nets and bamboo weir fishing boats. In addition, using theoretically calculated results (Tier 1), the emission factor presented by the Intergovernmental Panel on Climate Change (IPCC) was comparatively analyzed. On average, carbon emissions for each operating period in the bamboo weir and set net were calculated to be 0.16 and 3.58 kg CO₂ time^-1, respectively; and the measurement values (Tier 4) for each tool were about 4-17 times lower than their respective theoretical values (Tier 1). Significant differences were found based on engine performance. As port entry, port departure, and operating periods of the vessels show negligible variation with short distances, the operation of the vessel engine was considered as the main variable for carbon emissions in anchovy set net fishing.

• Journal of KIBIM
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• v.8 no.2
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• pp.41-50
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• 2018

The current study focused on the utilization of building information modeling (BIM) data in steel-frame structures, which help to reduce project durations because they employ prefabricated structural members that are assembled on-site. In addition, a business process model was proposed using BIM data collected during the preconstruction, structural steel fabrication, and on-site construction phases of an actual steel-frame project. The ultimate expectation is that BIM data support at each phase, as well as the increased understanding among project participants, will result in an increase in project management productivity. The results from the current study are summarized as follows: To implement a BIM capable of application to steel-frame projects and data utilization, existing theories were studied to develop the construction project steps, both generally into the preconstruction (A1), steel fabrication (A2), and on-site construction phases, (A3) and specifically into 19 BIM-applicable phases. Based on the derived BIM-applicable phases, the model elements of the BIM object were identified, and the shortcomings of existing steel-frame projects were ameliorated, resulting in an improved data flow model. Moreover, for the proposed BIM data flow to progress efficiently, the BIM specialist needs to be well-acquainted with the phase-specific three-dimensional (3D) model output, and the infrastructure to construct an error-free 3D model must be provided. Based on the actual construction example, the BIM data utilized steel-frame projects - via production reports, clash checks, two-dimensional (2D) drawings, four-dimensional (4D) simulations, and 3D scanning - to make cooperation and communication among participants easier.

• MISULJARYO - National Museum of Korea Art Journal
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• v.99
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• pp.50-71
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• 2021

The Five-story Stone Pagoda from the Dongsa-ri Temple Site in Buyeo, dated to early Goyeo Dynasty, is valuable in that it is the southernmost example of the capital Kaesong pagoda style. This pagoda exhibits characteristics of the central Goryeo style featured in the pagodas built in and around the capital Kaesong, such as the diagonally curved section of the support for the cover stone above the upper stereobate. It also shares stylistic affinities with eleventh-century stone pagodas. The ansangmun (elephant eye patterns) in the lower stereobate of the Dongsa-ri Five-story Stone Pagoda resemble those in the pedestal of the Stone Seated Buddha (which was likely repaired in 1028 during the reign of King Hyeonjong), at the Jeongrimsa Temple site in Buyeo. It also reflects elements found in the flagpole supports from the Cheonheungsa Temple site in Cheonan. The sculpting techniques used in these patterns are also similar. Such congruencies suggest that the Dongsa-ri Five-story Stone Pagoda was built in the eleventh century. The Dongsa-ri Temple Site in Buyeo, located near the Geumgang River, served as a principal route for transporting grain-tax during the Goryeo Dynasty. It was also situated along the way to the Goryeo royal temple, Gaetaesa Temple. The geographical significance of the site and the extensive repairs undertaken at Jeongrimsa Temple during the reign of King Hyeonjong (r. 1009-1031) of the Goryeo Dynasty appear to have impacted the production of the Dongsa-ri Five-story Stone Pagoda. The Dongsa-ri Five-story Stone Pagoda also bears stylistic resemblances to the stone pagoda and flagpole supports found at neighboring Cheonheungsa Temple, which is presumed to be related to the establishment of Honggyeongsa (or Honggyeongwon) Temple in 1021 in Cheonan. This indicates the route of the transmission of the Kaesong pagoda style. The Five-story Stone Pagoda from the Dongsa-ri Temple Site pays testimony to the cultural accomplishments of eleventh-century stone artworks in Buyeo and adjacent regions. This pagoda embodies the majestic and assertive aesthetics that define of the Goryeo Dynasty, as do early Goryeo colossal Buddhist sculptures, including the Stone Standing Maitreya Bodhisattva at Daejosa Temple in Buyeo, the Stone Standing Buddha Triad at Gaetaesa Temple in Nonsan, and the Stone Standing Maitreya Bodhisattva at Gwanchoksa Temple in Nonsan. All of these bear similarities to the massive stone lantern and pagoda at Hyeonhwasa Temple in the capital Kaesong. The production of the light, sleek, sharp, and sophisticated Dongsa-ri Five-story Stone Pagoda is presumed to reflect the maturity of the cultural competence of the people in Dongsa-ri, Buyeo under the influence of Buddhist culture from the capital Kaesong during the eleventh century, a time marked by active cultural exchanges among regions.

• 한국신재생에너지학회:학술대회논문집
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• 2005.06a
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• pp.264-267
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• 2005

수소의 소규모 분산 생산 기술은 본격적 인 수소 인프라가 도입되기 전에 연료전지 자동차의 수소 충 전용이나 분산 발전형 연료전지의 수소 공급을 위해 필요하다. 생산 용량은 수소 기준으로 $10\~100 Nm^3/hr$ 정도로 현재로선 천연가스의 수증기 개질법이 가장 경제적인 공정으로 알려져 있다. 소규모 생산에 따른 열효율 저하를 줄이 기 위해 단위 공정들이 통합된 컴팩트 개질 시스템의 개발이 필요하다. 핵심 기술인 컴팩트 리포머의 국산화 기술 확보를 위하여 $20 Nm^3/hr$용량의 동심관형 리포머를 설계, 제작하였다. 내부구조는 제작의 단순화를 고려하여 중첩된 동심관이 배열되었고 압력 손실과 열웅력 발생을 억제하도록 유로를 배치하였다. 수증기개질 반응에 필요한 반응열은 리포머 본체에 부착된 버너를 이용하여 공급하였다. 성능 측정을 위한 부속 기기로 상온 흡착식 탈황기, 폐열 회수형 수증기 발생기, 반응물 예열을 위한 열교환기, 생성 가스 응축기를 설계 제작하여 전체 리포밍 시스템을 구성하였다. 반응 온도 $680\~720^{\circ}C$, 탄소 대 수중기 비(S/C ratio) $2.7\~3.2$ 조건에서 수증기 개질 반응을 수행하였다. 해당 반응 조건에서 메탄 전환율 $89\%$ 이상, 저위 발열량 기준 개질 열효율 $70\%$ 이상을 달성하였고 개질 생성가스 내 수소의 최대 유량은 $23.4Nm^3/h$였다. 개발된 리포밍 시스템은 고순도 수소 생산이 필요한 경우, 수소 수율 향상을 위한 고온 수성 가스 전화 반응기를 통합 가능하도록 열교환기 구성을 조정할 수 있으며 용융 탄산염 연료전지와 같이 고온형 연료전지의 경우 $550^{\circ}C$ 이상으로 개질 생성 가스를 공급하도록 구성할 수도 있다. 향후 리포머 본체의 개질 효율 향상 및 장치 소형화, 부속 기기의 최적화를 통한 전체 리포밍 시스템 개선, 스케일 업 설계를 위한 엔지니어링 설계 패키지 구성을 계획하고 있다.

• Journal of Conservation Science
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• v.22
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• pp.15-30
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• 2008

The roof tiles from the tomb in Baekje Kingdom of the Danjiri site in Gongju, Korea were studied for the production techniques and raw material provenance based on archaeometric characteristics. The roof tiles had traditional shapes of Baekje Kingdom, which show flow texture on the surfaces and sections with the roof tiles of hard or soft-type. These roof tiles were locally produced, using refining soils according to mineralogical and geochemical characteristics. Also roof tiles were divided to 2 groups by firing temperature and physical properties. One of them had soft with porous texture and fired probably about 700 to $900^{\circ}C$. The other had hard with vitrified texture and probably fired about 940 to $1,020^{\circ}C$. Buried for long time and used as a tomb, roof tiles had experienced chemical alteration due to the enrichments of trace elements abundant in human tissues.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.2
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• pp.41-47
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• 2021

Manufacturing is facing radical changes around the world. The manufacturing industry, which has been changing since Germany, is now being introduced, improved, and developed worldwide by manufacturers under the name of smart factory. By utilizing IT technologies such as artificial intelligence and cloud at the production site, the desire to break away from the past manufacturing environment is increasing. How these technologies will be efficient in the future, manufacturing worldwide now faces radical changes. The manufacturing industry, which has been changing since Germany, is now being introduced, improved, and developed worldwide by manufacturers under the name of smart factory. By utilizing IT technologies such as artificial intelligence and cloud at the production site, the desire to break away from the past manufacturing environment is increasing. Discussions continue on how these technologies can be used efficiently and effectively. Increasingly, the expansion of the range from factory areas to regions, countries, and around the world raises the need for international standards for interactions. In this paper, we propose a design and implementation method for managing facilities, sensors, etc. as assets and monitoring facility data collected through OPC UA.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.1140-1147
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• 2009

Productivity measurement of construction machinery is a significant issue faced by many contractors especially those involved in earthwork projects. Traditionally, equipment production rate has been estimated using data available in manufacturers' catalogues, results of previous construction projects, or personal experience and assessments of the site personnel. Actual production rates obtained after the completion of a project demonstrate the fact that most of these methods fail to provide accurate results and as a direct consequence, may lead to unrealistic project cost estimations prepared by the contractors. What makes this more critical is that in most cases, inadequate cost estimations lead the entire project to exceed the initial budget or fall behind the schedule. In this paper, a linear regression method to estimate bulldozer productivity is introduced. This method has been developed using SPSS-16 software package. The presented method is used to estimate the productivity of Komatsu D-155A1 series which is commonly used in many earthmoving operations in Iran. The data required for the numerical analysis has been collected from actual site observation and productivity measurement of 60 pieces of D-155A1 series currently being used in several earthmoving projects in Iran. Comparative analysis of the output data of the presented regression method and the existing productivity tables provided by the manufacturer shows that when compared to the actual productivity data collected on the jobsite, a significant increase in accuracy and a remarkable reduction of data variance can be achieved by using the presented regression method.

• Journal of Conservation Science
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• v.29 no.2
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• pp.139-147
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• 2013

This study focused on iron making related information through analyzing slags and furnace wall collected from iron production site of Suryong-ri Wonmorongi, Chungju. Total Fe content of slags were from 36.98% to 44.47% and this range was general recovery rate of iron in ancient. Compounds of calcium included slags was supposed to add intentionally during smelting process as deoxidation agent in order that these helped to separate iron from impurities. Furnace wall didn't make of high alumina clay because of low $Al_2O_3$. Microstructure and main components of slags show that No. 1 to 3 slags with fayalite and wustite were products of iron ore smelting. However, No.4 slag is more likely to smelt by iron sand because of ulvospinel with $TiO_2$ in No. 4 slag. Therefore, iron ore were not only used but iron sand in smelting and furnace wall made of general clay with low $Al_2O_3$ content in this area.

• Journal of Environmental Science International
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• v.26 no.2
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• pp.231-238
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• 2017

Rapid industrial development has led to a serious problem of pollution in the industrial sector. With the increasing social need for environmental protection, research on air pollution prevention equipment for reducing pollutants in industrial processes is actively being undertaken. The deterioration of existent, installed facilities, their increased emission rates, and the strengthening of the effluent quality standards make complying with permissible emission standards difficult. In fact, installing new electric precipitators or complementing existent facilities is inevitable. The expansion and complementation of the installed electrical precipitators have led to improvements in dust collection efficiency, shorter working times, and lower costs. Because of its easy installation and simple manufacturing process, the production method with the discharge electrode of an electric precipitator is widely used. The following conclusions were reached by classifying discharge electrodes into four types based on the production method and mutually comparing them by their dust collection efficiency. None of the four types used in this study were damaged by impact. However, we were able to confirm some strain from the compression sites of both type A and type B. Both type B and type C are expected to have greater dust collection efficiencies than the other models due to their large vibration transmissibility. Moreover, the high vibrational energy is expected to cause rapping damage during its operation. Particularly, in the case of type B, some of the strain was found at the end of the compression site. The coupling schemes of both type C and type D are out of vibration transmissibility. On the other hand, the ability to maintain straightness and solidity of the side is regarded as outstanding and stable. Type D has outstanding on-site workability, considering the presence of locking, structural stability, and work conditions. From these experiments, we determined that type C is the most ideal connection method of discharge electrode, considering its construction period of renovation. Type C is inferior to type D with regard to on-site workability. However, type C has outstanding dedusting transmission with regard to the straightness, solidity maintenance, and vibration of shearing stress.