• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.2
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• pp.983-989
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• 2013

The current research reviewed the design conditions that would maximize the efficiency of the hybrid collector that combines in one unit "cyclone-inertial impaction-bag filter". The computational analysis for the shape of cyclone entry predicts that a design that installs the guide vane at the entry of the tangential type cyclone brings a high-rpm and powerful vortex, very effective in promoting the deflection of coarse particles from the streamline at the cyclone. As the lower part of the cyclone is venturi-shaped, however, a strong flow downward of 4 to 5 m/sec persists through the lower part of the hopper, revealing the likely reentrainment of collected dust. And the removal of the venturi at the lower part of the cyclone would solve the problem of the reentrainment of collected dust. The acceleration of the flow velocity through the adjustment of the gap of the collision baffle would increase the effect of collision, but as the interference with the dust separation is expected, the original design should be kept for the baffle.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.11
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• pp.510-519
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• 2019

The aim of this study was to set a defect classification framework and evaluate the defect risks in apartment buildings For this, approximately 15,056 defect items for 133 apartment buildings were examined. As a result of the analysis, the major defect of the RC work was cracks, which were found mainly in public locations. Moreover, the RC work was found to exhibit a high defect risk of water problem and surface appearance, which are highly connected with cracks. Second, the finish work has a high defect risk because it is composed of various work types, and there are many kinds of materials and construction parts involved. Third, the major defects of the waterproof work were incorrect installation and missing tasks, which have high defect risks in the garage. This is because defects that require rework occur mainly in the underground garage. Based on these results, this study proposed countermeasures for defect risk management to be considered in the construction, handover, post-handover, and occupancy phases. These have been set in detail based on the three zones: low frequency high severity (LFHS), low frequency low severity (LFLS), and high frequency low severity (HFLS).

• Journal of KIISE:Software and Applications
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• v.35 no.10
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• pp.616-626
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• 2008

The face shape extracted by the depth values has different appearance as the most important facial feature information and the face images decomposed into frequency subband are signified personal features in detail. In this paper, we develop a method for recognizing the range face images by combining the multiple frequency domains for each depth image and depth fusion using fuzzy integral. For the proposed approach, the first step tries to find the nose tip that has a protrusion shape on the face from the extracted face area. It is used as the reference point to normalize for orientated facial pose and extract multiple areas by the depth threshold values. In the second step, we adopt as features for the authentication problem the wavelet coefficient extracted from some wavelet subband to use feature information. The third step of approach concerns the application of eigenface and Linear Discriminant Analysis (LDA) method to reduce the dimension and classify. In the last step, the aggregation of the individual classifiers using the fuzzy integral is explained for extracted coefficient at each resolution level. In the experimental results, using the depth threshold value 60 (DT60) show the highest recognition rate among the regions, and the depth fusion method achieves 98.6% recognition rate, incase of fuzzy integral.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.78-85
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• 2020

The scaffolding system, which is a construction workbench of the cargo containment for a membrane LNG carrier, is a large truss structure composed of various members. To shorten the installation period and process of the scaffolding system, it is effective to enlarge the mounting unit from the existing two stages to eight stages. Owing to the increase in lifting load according to the large size of the module, the stresses around the pin and hole will be increased significantly. In this study, a tensile strength test and contact stress analysis were performed to confirm the structural safety. The relatively large hole deformation was observed visually near the average load generated in the vertical pipe at the top through tensile strength tests. A contact stress calculation confirmed the stress distribution around the hole. The contact problem was dealt with in terms of the Herzian contact stress. The possibility of 8-stage loading was examined by comparing the yield strength and contact stresses of failure critical locations. As a result, the 8-stage loading method of the existing scaffolding material was inadequate, and a new loading method with proper safety is proposed.

• Journal of Korean Library and Information Science Society
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• v.45 no.3
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• pp.297-319
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• 2014

This research started from bringing up a problem about special situation of the library and information science, which is not easy to investigate its academic characteristics, although it has settled down as a powerful science studying related phenomena as well as education required for the whole process from production of information to consumption of it. Therefore, the purpose of this research is to questingly investigate whether the personal specialty and the experience of taking courses affect recognition of the term 'library and information', and if so, through which channel it influences. In this background, data were collected from 328 students of Chonnam National University for this research, and the following are the analysis results: first, as for the personal characteristics, differences were not generated according to gender and age, but according to scholastic year the results were different; second, as for the experience of taking courses, there were not differences according to whether or not of the experience, but the results varied according to the number and type of the experience; and third, most of the respondents surveyed understood the meaning of a term 'library and information' as the conception of covering the information contained in literature and information of it, regardless of the personal characteristics and the experience of taking courses. Through these results, it can be identified that the term 'library and information' meant in the library and information science is generally understood as expansion of range, rather than chemical combination of literature and information, it is a terminology with various meanings sometimes understood differently according to the special personal experiences, and it also needs scientific investigation of it.

• Journal of the Korean Institute of Landscape Architecture
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• v.46 no.3
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• pp.103-116
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• 2018

The Park Act (1967~1980) was the first law to define urban parks in Korea. The urban parks of that time were similar to a reservation area used for other purposes after giving regulation. Because 'the urban park as a reservation area' in the past is a repeated park issue in the present, it is necessary to consider the issues of the original law system that created the cause. From this perspective, this study analyzed the legislation to reserve an urban park by collecting bills and information about the factual relationship between 1960 70s park issues and the Park Act. Analysis showed that the reason for the adoption of different kinds of urban parks in the law of a nature park is that a negative list separated from the Urban Planning Act is required to curb private usage. Inherent in the Park Act, however, was the problem of allowing the encroachment of urban parks by governmental power. (1) The Park Act sets out a wide range of cases to abolish urban park. (2) Unclear setting of governmental power could abuse the urban park. (3) Insufficient standards were able to erode the urban park with large for-profit facilities. (4) The inactivity of the Urban Public Park Committee had reduced democratic decision-making and professional judgement on park issues. Therefore, the Park Act was characterized as infringing on the environment and right to urban parks and took a passive attitude in creating parks and in citizen usage thereof. The Park Act had limitations as a progenitor for establishing the characteristics and concepts of urban parks.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.5
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• pp.902-910
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• 2016

Recently, the volume of mobile data traffic increases exponentially due to the emergence of various mobile services. In order to resolve the problem of mobile traffic increase, various new technologies have been devised. Especially, two-way relay communication in which two nodes can transfer data simultaneously through relay node, has gained lots of interests due to its capability to improve spectral efficiency. In this paper, we analyze the SM-PNC which combines Physical-layer Network Coding (PNC) and Spatial Modulation (SM) under two-way relay communication environment. Log-Likelihood Ratio (LLR) is considered and both separate decoding and direct decoding have been taken into account in performance analysis. Through performance evaluation, we have found that the bit error rate of the proposed scheme is improved compared to that of the conventional PNC scheme, especially when SNR is high and the number of antennas is large.

• KIPS Transactions on Computer and Communication Systems
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• v.2 no.6
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• pp.279-290
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• 2013

In digital forensics log files have been stored as a form of large data for the purpose of tracing users' past behaviors. It is difficult for investigators to manually analysis the large log data without clues. In this paper, we propose a text mining technique for extracting intrusion logs from a large log set to recommend reliable evidences to investigators. In the training stage, the proposed method extracts intrusion association words from a training log set by using Apriori algorithm after preprocessing and the probability of intrusion for association words are computed by combining support and confidence. Robinson's method of computing confidences for filtering spam mails is applied to extracting intrusion logs in the proposed method. As the results, the association word knowledge base is constructed by including the weights of the probability of intrusion for association words to improve the accuracy. In the test stage, the probability of intrusion logs and the probability of normal logs in a test log set are computed by Fisher's inverse chi-square classification algorithm based on the association word knowledge base respectively and intrusion logs are extracted from combining the results. Then, the intrusion logs are recommended to investigators. The proposed method uses a training method of clearly analyzing the meaning of data from an unstructured large log data. As the results, it complements the problem of reduction in accuracy caused by data ambiguity. In addition, the proposed method recommends intrusion logs by using Fisher's inverse chi-square classification algorithm. So, it reduces the rate of false positive(FP) and decreases in laborious effort to extract evidences manually.

• KIPS Transactions on Computer and Communication Systems
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• v.5 no.10
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• pp.347-352
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• 2016

Recently, IoT technology has been applied in various field. In particular, the technology focuses on analysing large amount of data that has been gathered from the environmental sensors, to provide valuable information. This technique has been actively researched in the agro-industrial sector. Many researches are underway in the monitoring and control for growth crop environment in agro-industrial. Normally, the average weather data is provided by the manual agro-control method but the value may differ due to the different region's weather and environment that may cause problem in the disease and insect-pest prevention. In order to develop a suitable integrated system for fruit tree, all the necessary information is obtained from the Jeollanam-do province, which has the high production rate in the Korea. In this paper, we propose an integrated support platform for the growing crops, to minimize the damage caused due to the weather disaster through image analysis, forecasting models, by using the micro-climate weather information collection and CCTV. The fruit tree damage caused by the weather disaster are controlled by utilizing various IoT technology by maintaining the growth environment, which helps in the disease and insect-pest prevention and also helps farmers to improve the expected production.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.1
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• pp.136-145
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• 2015

This study analyzes the status and problems of current parcel management in the public land, and it suggests measures for improvement based on the analysis. For this, it looked into the status and problems of the public land's parcel management. One of the major problems was that the number of parcels was continuously increasing due to insufficient parcel management. The study found that the number was increasing every year by 128,520 parcels on average as of 2008. It also found that there was also non-coincidence between the status and the land use conditions in the cadastral records. An increasing set of minute parcels (minute polygon) has appeared because of these outstanding issues, and these errors have been included in the statistics survey on parcels, negatively influencing the credibility of the data. This study suggests ways to improve these issues including reduction in the number of parcels through annexation, enhancement of credibility of cadastral information through cadastral confirmation survey, and registration and management of public land parcels in consideration of the current status.