• International conference on construction engineering and project management
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• 2009.05a
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• pp.285-291
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• 2009

Water is a strategic resource for Singapore due to its small land mass and more than half of the mainland serves as catchment for raw water, including construction sites. Construction site typically involves earthworks and in conjunction with the frequent and intense rainstorm in Singapore, produce runoff of high turbidity due to suspended sediments. The resulting high concentration of suspended sediment in construction site runoff very often leads to aesthetically unpleasant reservoirs and potentially increases the treatment cost of raw water. To mitigate this, the local standard requires the discharged concentration of total suspended solids of construction runoff leaving a construction site to be less than 50mg/l which is a very high standard. This paper will present, examine and discuss particular issues and practices of Singapore's construction industry in meeting this requirement. The focus will be on two areas: Government lead initiatives and industry practices. How the government agencies worked together with the industry professionals to develop a system to ensure meeting of the standard is discussed. In addition, the types of industry practices, including various Best Management Practice to reduce erosion in construction sites and implement effective sedimentation on construction sites are examined.

• International conference on construction engineering and project management
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• 2013.01a
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• pp.531-538
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• 2013

The coordination and control of construction projects is vital if a project is to be a success. Almost all analysis has shown that these can only be achieved if good quality communication can be maintained on a construction site. This research focuses on the role that tablet computers could play in enhancing this communication. The following points are investigated in this paper: (a) Whether a tablet computer can enable users to monitor project progress more efficiently than traditional methods, (b) How the tablet computer fits within the project management iron triangle in construction, (c) The two different psychological impacts of information transmission for the end user using a tablet computer (i) The expectancy to transmit information frequently and rapidly from tablet computer users to project members whilst working onsite (ii) The mode of information transmission to the cognition of the transmitted information to the tablet computer. Through the use of structured interviews and questionnaires, the opinions of individuals within various disciplines in construction were canvassed. The approach adopted in this paper deals with understanding both the soft and hard issues for deploying such a system. This research enabled the authors to develop a base framework incorporating the key factors which are relevant for implementing a tablet computer based on information flows primarily.

• Journal of the Korean Society of Systems Engineering
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• v.9 no.1
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• pp.33-45
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• 2013

Systems Engineering Approach was applied to the development of operator-support core management system based on the on-site operation experience and document of core management procedures, which is for enhancing operability and safety in PHWR (Pressurized Heavy Water Reactor) operation. The dissertation and definition of the system were given on th basis of investigating and analyzing the core management procedures. Fuel management, detector calibration, safety management, core power distribution monitoring, and integrated data management were defined as main user's requirements. From the requirements, 11 upper functional requirements were extracted by considering the on-site operation experience and investigating documents of core management procedures. Detailed requirements of the system which were produced by analyzing the upper functional requirements were identified by interviewing members who have responsibility of the core management procedures, which were written in SRS (Software Requirement Specification) document by using IEEE 830 template. The system was designed on the basis of the SRS and analysis in terms of nuclear engineering, and then tested by simulation using on-site data as a example. A model of core power monitoring related to the core management was suggested and a standard process for the core management was also suggested. And extraction, analysis, and documentation of the requirements were suggested as a case in terms of systems engineering.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.11a
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• pp.210-211
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• 2005

[ $(K_{0.5}Na_{0.5})NbO_3$ ](KNN) 세라믹스의 소결 특성과 압전 특성을 높이기 위해 B-site에 Sb를 치환하여 Sb함량에 따른 특성을 측정 하였다. Sb 의 함량을 0mol $\sim$ 0.1mol 까지 첨가한 결과 소결 밀도는 Sb의 첨가량이 많아질수록 증가하다 Sb-0.08mol에서 4.40g/$cm^3$으로 가장 높은 밀도를 가졌으며, 여기서의 전기기계 결합 계수가(Kp) 0.45로 높은 값을 나타내었다. 상전 이 온도는 375$^{\circ}C$로 순수한 KNN 의 420$^{\circ}C$ 보다 약 45$^{\circ}C$정도 떨어졌으나 orthorhombic에 서 tetragonal 로 바뀌는 전이 온도는 KNN이 220$^{\circ}C$, KNNS 가 225$^{\circ}C$로 크게 변하지 않았다.

• Journal of The Korean Society of Agricultural Engineers
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• v.61 no.6
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• pp.21-30
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• 2019

Livestock odor is comprised of mixed type of odorous compounds. Among these, ammonia ($NH_3$) and hydrogen sulfide ($H_2S$) are the two known major odor causing substances. Because high odor concentration reduces productivity of livestock and causes damage to the surrounding communities, quantitative analysis is needed to manage the odor inside and outside the livestock facilities. It is also necessary to evaluate odor dispersion according to the distance between the receptors taking into account the influence of odor source and weather condition. Therefore, in this study, we tried to evaluate the internal environment and odor dispersion from experimental pig house considering weather conditions. An experimental farm was specifically selected to eliminate the interference of odors generated by adjacent farms. $NH_3$ and complex odor were quantitatively analyzed using a gas detector and air dilution sensory method. The concentration of $NH_3$ and complex odor in pig house showed a distinct concentration difference according to the cleaning and ventilation conditions. $NH_3$ concentration and complex odor was lower than emission standard in the pig house and at the site boundary. The average $NH_3$ concentration (P1~P3) and the $NH_3$ concentration at the site boundary (S1) were strongly correlated with R=0.77. While the correlation for complex odor inside and at the site boundary had R=0.52. The correlation coefficient between $NH_3$ and the complex odor was 0.80.

• International conference on construction engineering and project management
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• 2022.06a
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• pp.353-360
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• 2022

Due to the dense and complicated working environment, the construction industry is susceptible to many accidents. Worker's fall is a severe problem at the construction site, including falling into holes or openings because of the inadequate coverings as per the safety rules. During the construction or demolition of a building, openings and holes are formed in the floors and roofs. Many workers neglect to cover openings for ease of work while being aware of the risks of holes, openings, and gaps at heights. However, there are safety rules for worker safety; the holes and openings must be covered to prevent falls. The safety inspector typically examines it by visiting the construction site, which is time-consuming and requires safety manager efforts. Therefore, this study presented a worker-driven approach (the worker is involved in the reporting process) to facilitate safety managers by developing integrated computer vision and inertia sensors-based mobile applications to identify openings. The TensorFlow framework is used to design Convolutional Neural Network (CNN); the designed CNN is trained on a custom dataset for binary class openings and covered and deployed on an android smartphone. When an application captures an image, the device also extracts the accelerometer values to determine the inclination in parallel with the classification task of the device to predict the final output as floor (openings/ covered), wall (openings/covered), and roof (openings / covered). The proposed worker-driven approach will be extended with other case scenarios at the construction site.

• International conference on construction engineering and project management
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• 2020.12a
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• pp.455-462
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• 2020

Noise which is unwanted sound is a serious pollutant that can affect human health, as well as the working and living environment if exposed to humans. However, current noise management on the construction project is generally conducted after the noise exceeds the regulation standard, which increases the conflicts with inhabitants near the construction site and threats to the safety and productivity of construction workers. To overcome the limitations of the current noise management methods, the activities of construction equipment which is the main source of construction noise need to be managed throughout the construction period in real-time. Therefore, this paper proposed a framework for automatically detecting noise sources in construction sites in real-time based on convolutional neural networks (CNNs) according to the following four steps: (i) Step 1: Definition of the noise sources; (ii) Step 2: Data preparation; (iii) Step 3: Noise source classification using the audio CNN; and (iv) Step 4: Noise source detection using the visual CNN. The short-time Fourier transform (STFT) and temporal image processing are used to contain temporal features of the audio and visual data. In addition, the AlexNet and You Only Look Once v3 (YOLOv3) algorithms have been adopted to classify and detect the noise sources in real-time. As a result, the proposed framework is expected to immediately find construction activities as current noise sources on the video of the construction site. The proposed framework could be helpful for environmental construction managers to efficiently identify and control the noise by automatically detecting the noise sources among many activities carried out by various types of construction equipment. Thereby, not only conflicts between inhabitants and construction companies caused by construction noise can be prevented, but also the noise-related health risks and productivity degradation for construction workers and inhabitants near the construction site can be minimized.

• Journal of the Korean Institute of Landscape Architecture
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• v.35 no.1 s.120
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• pp.20-27
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• 2007

This paper presents a landscape design for the meeting plaza around the "Myeonmok" subway station. The site is located at 120-1 Myeonmok 1-dong, Jnngrang-gu, Seoul, and its area is approximately $2,664.7m^2$. The goal of the design was to make an environmentally friendly meeting and rest place which was related to the subway station. To achieve this goal, concepts of history, tradition, sense of place, community, environmental friendliness, and function were developed. For history, stone sculpture and art tiles symbolizing the paleolithic area were introduced because the site is located near an archaeological site of paleolithic min. For tradition, considering that the site is a 'sailing ship' form in terms of Pungsu theory, a sculpture symbolizing a sailing ship and paving patterns symbolizing waves were introduced. For asense of place, a grass hill, a waterfall and a pond symbolizing an old meadow for horse pasture was introduced. In addition, a multi-purpose round plaza as a meeting place for local community and subway users was proposed. A zelkova grove symbolizing a village forest was proposed for a restand relaxation area. All areas were designed to be environmentally friendly and barrier-free. Concepts for a defensible space wereadapted for safety because the site was a crime-prone area.

• KIEAE Journal
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• v.15 no.2
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• pp.87-94
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• 2015

Purpose: Lately, The mixed use development on railroad site came up in government policy about securing development available land for public rental housing and social cohesion. The Purpose of this study is to analyze the spatial composition characteristic in housing development example of domestic and foreign through the mixed-use development of railway depot. Method: Site cases are as follows: Shimura Depot(Japan), Kowloon Bay Depot(Hongkong), Chai Wan Depot (Hongkong), Tsuen Wan Depot(Hongkong), Montparnasse Station(France), Euralille Depot(France), Sin Jeong Depot (Korea), Tai Wai Depot(Hongkong), Tseung Kwan O Depot(Hongkong) and Rive Gauche(France). Railway Depot caused various problems such as the lacking of the feeling of solidarity of local inhabitants and the sense of community. In the case of Hong Kong and a France development example to solve these problems, the architectural characteristics appears. Result: At first it is located facilities together such as commerce, duties, the culture. Further, the publicity of the house place is strengthened because an open space, a park are developed on the railroad site. And a variety of connection systems appear between the outside space with a house housing complex built on the artificial ground. Particularly, the development example has an approach and convenience, and it was confirmed that publicness was considerably high.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.1216-1223
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• 2008

Displacement control of earth retaining wall is recognized as the most important item for insuring the stability of ground in urban deep excavation site near by major structure such as subway etc. The field monitoring system is classified by two types as manual system and automatic system. The application case of latter type of field monitoring is increased because real time measurement is possible in automatic system and that is correspondent with the recent constructional trend. Though the automatic monitoring system is more useful and advanced than manual monitoring system, accuracy of the system is not verified sufficiently. It was examined that the reliance of automatic monitoring system in this paper through the comparison of monitoring result obtained three urban excavation site in which the each type of monitoring system was executed concurrently. Result of the examination is that the two types of monitoring system is generally alike in view of monitoring result, so the engineering reliance of automatic system was confirmed in case site. This task was researched in restricted case site, it is expected more precise analysis from security of more data monitored and progressive study.