• International Journal of Internet, Broadcasting and Communication
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• v.12 no.2
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• pp.8-14
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• 2020

Recently, there was an increasing demand for an integrated access control system which is capable of user recognition, door control, and facility operations control for smart buildings automation. The market available door lock access control solutions need to be improved from the current level security of door locks operations where security is compromised when a password or digital keys are exposed to the strangers. At present, the access control system solution providers focusing on developing an automatic access control system using (RF) based technologies like bluetooth, WiFi, etc. All the existing automatic door access control technologies required an additional hardware interface and always vulnerable security threads. This paper proposes the user identification and authentication solution for automatic door lock control operations using camera based visible light communication (VLC) technology. This proposed approach use the cameras installed in building facility, user smart devices and IoT open source controller based LED light sensors installed in buildings infrastructure. The building facility installed IoT LED light sensors transmit the authorized user and facility information color grid code and the smart device camera decode the user informations and verify with stored user information then indicate the authentication status to the user and send authentication acknowledgement to facility door lock integrated camera to control the door lock operations. The camera based VLC receiver uses the artificial intelligence (AI) methods to decode VLC data to improve the VLC performance. This paper implements the testbed model using IoT open-source based LED light sensor with CCTV camera and user smartphone devices. The experiment results are verified with custom made convolutional neural network (CNN) based AI techniques for VLC deciding method on smart devices and PC based CCTV monitoring solutions. The archived experiment results confirm that proposed door access control solution is effective and robust for automatic door access control.

• Journal of the Korean Society of School Health
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• v.16 no.2
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• pp.13-23
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• 2003

To provide data necessary for effectively applying the HACCP system by understanding the current application condition of HACCP system and satisfaction level of the dietician in elementary schools, a mail-in survey was conducted on dieticians serving for 227 elementary schools applying HACCP system in Kyungsangbuk-Do since November 1, 2001 to December 20, 2001. 83.5% of the subjected schools were conducting more than 50% of HACCP cooking process management, and the level of cooking process management displayed significant relevance according to the number of dieticians serving the school meals. The area that was not well conducted in the field of HACCP system was proven to be water examination(94.0%), inspection on self-sanitation of cooks prior to cooking(90.6%), and maintenance of dry kitchen floor(l4.8%). The reason why the above areas are not well conducted was because of lack of time due to over workloads. Subjective dieticians had pointed out improvement of sanitary concept(58.1%) and improvement of self-sanitation (28.8%) as benefits of applying HACCP. 21.2% of the subjective dieticians were satisfied with application HACCP and 35.2% were dissatisfied with applying HACCP. In case of which the duration of applying the HACCP was longer than one year and in case of higher rate of HACCP cooking process management and longer work experience of the dieticians, the level of satisfaction was proven to be significantly higher. The most difficult things to follow in important management categories according to the features of dietitian work and work experience were food distribution of CCP7 step and maintenance of optimum temperature(70.7%). Subjective dieticians had pointed out insufficient facility or environment and lack of inspection equipments in order regarding problems of applying HACCP. Also in the level of necessity of improvement categories in applying HACCP, dieticians had replied that facility and equipment improvement was mostly needed. Due to the induction of HACCP system in school meals, comparatively well cooking process management is being conducted, and I believe it could contribute in securing safety and quality improvement of school meal by improving the sanitation concept of the dieticians. However, the satisfaction level of dieticians are rather low and there are many difficulties in maintaining optimum temperature in the process of food distribution and transportation process. Also, lack of facilities and environment, lack of inspection equipments and etc are pointed out as problems of inducing HACCP. Thus, to settle HACCP system, it is believed that brave investment must be preceded.

• Korean Journal of Construction Engineering and Management
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• v.7 no.4 s.32
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• pp.91-99
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• 2006

The purpose of this study is propose an Artificial Neural Network(ANN) model for the construction estimate of the public educational facility at conceptual stage. The current method for the preliminary cost estimate of the public educational facility uses a single-parameter which is based on basic criteria such as a gross floor area. However, its accuracy is low due to the nature of the method. When the difference between the conceptual estimate and detailed estimate is huge, the project has to be modified to meet the established budget. Thus, the ANN model is developed by using multi-parameters in order to estimate the project budget cost more accurately. The result of the research shows 6.82% of the testing error rates when the developed model was tested. The error rates and the error range of the developed model are smaller than those of the general preliminary estimating model at conceptual stage. Since the proposed ANN model was trained using the detailed estimate information of the past 5 years' school construction data, it is expected to forecast the school project cost accurately.

• Geomechanics and Engineering
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• v.33 no.3
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• pp.291-299
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• 2023

Monitoring contaminants in waste landfills on a seabed is important because the leachate affects the marine ecosystem and facility stability. The objective of this study is to optimize a time-domain reflectometry (TDR) probe using different coating materials and several electrodes to estimate contaminants in saline soil. Copper concentrations ranging from 0 mg/L to 10 mg/L were mixed in 3% salinity water to simulate contaminants in the ocean environment. Epoxy, top-coat, and varnish were used as coating materials, and two to seven electrodes were prepared to vary the number and arrangement of the electrodes. Test results showed that the varnish stably captured the increase in copper concentration, while the other coating materials became insensitive or caused leakage current. In addition, a TDR probe with more electrodes exhibited stable and distinct electromagnetic signals. Thus, the TDR probe with seven electrodes coated with varnish was effectively used to estimate contaminants in saline soil.

• Journal of the Korean Institute of Educational Facilities
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• v.23 no.1
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• pp.23-32
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• 2016

This research aims to securement of crime prevention for school violence and invasion from outside etc. For crime prevention efficiency secure, It has purpose for school current state comprehension and prevention essential elements deduction autonomously etc. Furthermore, school facility crime dangerousness evaluation checklist is looked for autonomous monitoring tools. This checklist made from analysis of frequency, importance and check availability of 6 native and foreign existing CPTED evaluation's 360 indexes. Then, 81 indexes was derived from analysis, and that indexs verified through focus group interview. Finally, total 47 articles checklist emerged with general details, external school, internal school, and school administrative managements. Through this checklist, school can select essential elements of the preferential crime prevention autonomously, and so it is expected to prompt improvement of crime dangerousness elements, school violence and reduction of crime rate.

• Journal of the Korea Institute of Building Construction
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• v.19 no.3
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• pp.239-246
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• 2019

According to the survey on the status of aged buildings in Korea, A number of concrete buildings deterioration such as houses and apartment buildings has been increased rapidly. To solve this problem, the research related to the facility management, that is one of the importance factor, for monitoring buildings has been increased. The research is divided into Survey-based and Technique-based. However, the problem is that Survey-based research is required a lot of time, money and manpower for management. Also, safety cannot be guaranteed in the case of high-rise buildings. Technique-based research has limitations to applying to the current facility maintenance system, as detailed information of deteriorated facilities is difficult to grasp and errors in accuracy are feared. Therefore, this paper contribute to improve the environment of facility management by 4D maps using UAV, camera and Pix4D mapper program to make 3D model. In addition, it is expected to suggest that residents will be offered easy verification to their buildings deterioration.

• Journal of the Korean housing association
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• v.27 no.6
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• pp.19-29
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• 2016

As a lifeway and social change, the neighborhood build up around elementary school based on Perry's Neighbourhood Unit becomes change. Elementary School does not function as a center of residents' activity or community any longer. Activities occurred near the school move to the community streets that many facilities are distributed to, while utilization of facilities near schools becomes lower. On the bases of the current states, this study aims to draw a practical neighborhood center of residential areas by case study. The research is being mainly about low-rise residential areas in Seoul which includes one elementary school at least. In order to deduct the center of neighborhood, the survey takes two steps. At the preliminary survey, conduct the observation and do an interview to investigate awareness and actual status. Also to analyze practical center, do a main survey about land value, pedestrian volume, distribution of public transit and facility density. The research result shows that there is another activated center street not nearby elementary school in every case. This study assumes that the neighborhood center is not limited around elementary school and could variously build up by circumstances. It has significance that we present a question about the traditional theory and also could be references of the future city maintenance in the long term.

• Korean Journal of Heritage: History & Science
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• v.52 no.4
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• pp.124-141
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• 2019

This research explored the relationship between the water quality issue of Wolji Pond (Anapji Pond) with the maintenance of the channel flow circulation system. The water supply and drainage system closely related to the circulation system of pond has been reviewed, rather than the existing water supply and drainage system that has been analyzed in previous studies. As a result of reviewing the water supply system, it has been learned that the water supply system on the southeastern shore of Wolji Pond, being the current water supply hole, has been connected to the east side garden facility (landscaping stone, curved waterway, storage facility of water) between the north and south fence and the waterway. This separate facility group seems to have been a subject of the investigation of the eastern side of Wolji Pond, with the landscaping stones having been identified in the 1920's survey drawings. The water supply facility on the southeastern shore, being the suspected water supply hole, seems to have some connection with the granite waterway remaining on the building site of Imhaejeon (臨海殿) on the southern side of Wolji Pond. It is inferred that it provides clean water, seeing that the slope towards the southwestern shore of Wolji Pond becomes lower, the landscaping stones have been placed in the filter area, and it is present in the 1920's survey drawings and the water supply hole survey drawing of 1975. The water drainage facility on the northern shore is composed of five stages. The functions of the wooden waterway and the rectangular stone water catchment facility seem not to be only for the water drainage of Wolji Pond. In light of the points that there are wood plugs in the wooden waterway and that there is a water catchment facility in the final stage, it is judged that the water of Balcheon Stream (撥川) may be charged in reverse according to this setup. Namely, the water could enter and exit in either direction in the water drainage facility on the northern shore It also seems that the supply to the wooden waterway could be opened and shut through the water catchment facility of rectangular stone group as well. The water drainage facility on the western shore is very similar to the water drainage facility on the northern shore, so it is difficult to avoid the belief that it existed during the Silla Dynasty, or it has been produced by imitating the water drainage facility on the northern shore at some future point in time. It seems to have functioned as the water drainage facility for the supply of agricultural water during the Joseon Dynasty. The water supply and drainage facilities in Wolji Pond have been understood as a systematized distribution network that has been intertwined organically with the facility of Donggung Palace, which was the center of the Silla capital. Water has been supplied to each facility group, including Wolji Pond, through this structure; it includes the drainage system connecting to the Namcheon River (南川) through the Balcheon Stream, which was an important canal of the capital center.

• International Journal of Air-Conditioning and Refrigeration
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• v.6
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• pp.36-44
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• 1998

R-410a and R-407c which have the best potential among R-22 alternatives were tested as drop-in refrigerants against a set of R-22 baseline tests. The performance evaluations were carried out in a psychometric calorimeter test facility using the residential spilt type air conditioner under the ARI rating conditions. Except the lubricant and hand-operated expansion valve, the other parts of the air conditioner were the same with the commercial system. Performance characteristics were measured; compressor power, capacity, VCR, mass flow rate and COP. The tests showed that R-407c can be directly charged into the current refrigeration system because its vapor pressure and other thermochemical properties are similar to those of R-22. However, it is required to change the volume flow rate of compressor in order to achieve the volumetric capacity of R-22. This results from its relatively small VCR and capacity. Meanwhile, R-410a has vapor pressure values too high to be substituted for the current system and this resulted relatively low COP of R-410a compared to that of R-22.

• Journal of Korean Library and Information Science Society
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• v.41 no.3
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• pp.133-154
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• 2010

With the introduction of new teacher evaluation system, teacher librarians' evaluation indicators and questions were presented for the first time. The purpose of this study is to review the validity of current indicators and questions and to develop new one, based on it. The result is as follows : Current indicators mainly focus on the management of school library facility and collection, not on teacher librarians' educational activities and have the low validity to evaluate the expertise of teacher librarians. As a result, this study will suggest new evaluation indicators and questions to evaluate their expertise appropriately.