• Journal of the Architectural Institute of Korea Planning & Design
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• v.34 no.9
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• pp.77-86
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• 2018

Demand for construction technology is expected to change due to changes in domestic and foreign construction markets and the fourth industrial revolution. In particular, demand for project management strategy and project management capability is even more increasing rather than existing production technology capability. However, the current re-education program for engineers and technicians in construction industry is not matching the need of improving capacity required to reflect the demand of construction technology from construction industry. Therefore, in this study, as a part of efforts in innovating the current global construction talent re-education system to cope with the change in the construction industry, we analyzed the difference between the demand of construction technology and the present condition of construction re-education program. In order to investigate the current status of re-education of construction, questionnaires were prepared to gather opinions from construction engineers who attended construction re-education program and also from industrial partners that are jointly doing business. This study can be an example to improve the construction re-education program as a system for substantially reinforcing the competence of engineers rather than those programs that are merely verifying and/or extending engineers' certification.

• Journal of Korean Institute of Architectural Sustainable Environment and Building Systems
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• v.12 no.6
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• pp.641-654
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• 2018

Elevator noise in apartment houses is one of the factors which prevent the residents from quiet and comfortable life. The elevator noise measurement method [KS F ISO 16032] is introduced from the matching ISO standard, however, it has problems in the application to the actual measurement. To visualize the problems, measurements in an apartment house are conducted, which has been suffering from the elevator noise for a long time. The measurement itself is extremely difficult due to the low sound pressure level of elevator, which is lower than 35 dB (A), and the even higher background noise level. However the vibration levels measured at the same time are relatively less disturbing As a result of vibration measurement, it was found that the vibration is clearly measured on the wall, and presents a high correlation coefficient of over 0.8 with the noise levels measured This shows that the vibration level measured on the elevator walls may be rather reliable numbers than the elevator noise levels in the actual noisy condition of elevator halls and the vicinity.

• ETRI Journal
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• v.44 no.1
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• pp.73-84
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• 2022

The moving picture experts group (MPEG) immersive video (MIV) technology has been actively developed and standardized to efficiently deliver immersive video to viewers in order for them to experience immersion and realism in various realistic and virtual environments. Such services are provided by MIV technology, which uses multiview videos as input. The pruning process, which is an important component of MIV technology, reduces interview redundancy in multiviews videos. The primary aim of the pruning process is to reduce the amount of data that available video codec must handle. In this study, two approaches are presented to improve the existing pruning algorithm. The first method determines the order in which images are pruned. The amount of overlapping region between the source views is then used to determine the pruning order. The second method considers global region-wise color similarity to minimize matching ambiguity when determining the pruning area. The proposed methods are evaluated under common test condition of MIV, and the results show that incorporating the proposed methods can improve both objective and subjective quality.

• The Bulletin of The Korean Astronomical Society
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• v.46 no.1
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• pp.38.3-38.3
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• 2021

We are developing an optomechanical design of infrared telescope for the CubeSat and Unmanned Aerial Vehicle (UAV) which adapts the Linear Astigmatism Free- Three Mirror System in the confocal off-axis condition. The small entrance pupil (diameter of 40 mm) and the fast telescope (f-number of 1.9) can survey large areas. The telescope structure consists of three mirror modules and a sensor module, which are assembled on the base frame. The mirror structure has duplex layers to minimize a surface deformation and physical size of a mirror mount. All the optomechanical parts and three freeform mirrors are made from the same material, i.e., aluminum 6061-T6. The Coefficient of Thermal Expansion matching single material structure makes the imaging performance to be independent of the thermal expansion. We investigated structural characteristics against external loads through Finite Element Analysis. We confirmed the mirror surface distortion by the gravity and screw tightening, and the overall contraction/expansion following the external temperature environment change (from -30℃ to +30℃).

• Journal of Korean Ophthalmic Optics Society
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• v.4 no.2
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• pp.45-49
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• 1999

The second harmonic, wavelength is 397nm, of the continuous wave diode laser, whose maximum power is 35mW, was generated in $LiIO_3$ crystals in a ring enhancement cavity. 5mm- and 10mm-long crystals cut $43.21^{\circ}$ for optic axis were used in this experiment. Both surfaces of those were anti-reflection coated for 794nm. In case the crystal was inserted into the cavity, the condition of separation between two concave mirrors for the optimum mode matching was found. The conversion efficiency of second harmonic generation was increased by the resonant enhancement of pumping power in the ring enhancement cavity, and the frequency of diode laser was locked to that of the counter-propagation mode generated from the surface of crystal. When the pumping power was 28 mW, the infrared buildup factor was about 45 without the crystal, and 14 with the crystal due to the transmission loss of crystal. The maximum second harmonic powers of $1.5{\mu}W$ and $6.6{\mu}W$ were obtained, and corresponding conversion efficiencies were $(6.584{\pm}0.56){\times}10^{-3}$%, $2.6{\pm}0.21){\times}10%{-2}$% in 5mm- and 10mm-long $LiIO_3$, respectively.

• Journal of Korean Home Economics Education Association
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• v.19 no.2
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• pp.103-114
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• 2007

The purpose of this study is to satisfy students in adolescent trends of school uniforms and to provide them with useful material with matching current fashions by analyzing the attitude of students toward uniform transformation in female highschool students and investigating factors influencing on behaviors of uniform transformation. The subjects of this study are 30 students in Daegu with the basic ways of investigating such as depth interview and survey. The results are as follows; First, students agree to wearing school uniforms. As the main reason for wearing school uniforms, students put emphasis on peer pressure. It is also analyzed that the figure of students' body have some influence on the attitude of students toward wearing uniform while students' appearance have no influence on the attitude of students toward wearing uniform. Second, students showed high satisfaction in school uniforms. While students are satisfied with design and color of school uniform, they are not satisfied with practicality, economic efficiency and the quality of textile. Third, the study shows most students have experience of uniform transformation as a result of depth interview about actual condition of uniform transformation. Whereas students usually wear the jacket with its width and length shortened, they tend to lengthen skirt and unstitch pleat of skirt. Fourth, there are many reasons for uniform transformation as a result of depth interview with students. Transformation for satisfying aesthetic desire tops the list, followed by transformation for matching, transformation for peer pressure. As shown by the results above, every school needs to make various efforts to satisfy students, teachers and parents by considering and using students' opinion in order to choose the better school uniforms. In addition, the study related to school uniform transformation need to have more various investigating ways to acquire more authentic results such as expanding the subjects to not only students but also teachers and parents and in-depth comparison between subjects.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.38 no.3
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• pp.258-268
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• 2001

The compression method is necessarily used to send the high quality moving picture that contains a number of data in image processing. In the field of moving picture compression method, the motion estimation algorithm is used to reduce the temporal redundancy. Block matching algorithm to be usually used is distinguished partial search algorithm with full search algorithm. Full search algorithm be used in this paper is the method to compare the reference block with entire block in the search window. It is very efficient and has simple data flow and control circuit. But the bigger the search window, the larger hardware size, because large computational operation is needed. In this paper, we design the full search block matching motion estimator. Using the DCT DC values, we decide luminance. And we apply 3 bit compare-selector using bit plane to I(Intra coded) picture, not using 8 bit luminance signals. Also it is suggested that use the same selective bit for the P(Predicted coded) and B(Bidirectional coded) picture. We compare based full search method with PSNR(Peak Signal to Noise Ratio) for C language modeling. Its condition is the reference block 8$\times$8, the search window 24$\times$24 and 352$\times$288 gray scale standard video images. The result has small difference that we cannot see. And we design the suggested motion estimator that hardware size is proved to reduce 38.3％ for structure I and 30.7％ for structure II. The memory is proved to reduce 31.3％ for structure I and II.

• Journal of the Korean Solar Energy Society
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• v.28 no.2
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• pp.64-69
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• 2008

As the grid-connected photovoltaic power conditioning systems (PVPCS) are installed in many residential areas, these have raised potential problems of network protection on electrical power system. One of the numerous problems is an Islanding phenomenon. There has been an argument that it may be a non-issue in practice because the probability of islanding is extremely low. However, there are three counter-arguments: First, the low probability of islanding is based on the assumption of 100% power matching between the PVPCS and the islanded local loads. In fact, an islanding can be easily formed even without 100% power matching (the power mismatch could be up to 30% if only traditional protections are used, e.g. under/over voltage/frequency). The 30% power-mismatch condition will drastically increase the islanding probability. Second, even with a larger power mismatch, the time for voltage or frequency to deviate sufficiently to cause a trip, plus the time required to execute a trip (particularly if conventional switchgear is required to operate), can easily be greater than the typical re-close time on the distribution circuit. Third, the low-probability argument is based on the study of PVPCS. Especially, if the output power of PVPCS equals to power consumption of local loads, it is very difficult for the PVPCS to sustain the voltage and frequency in an islanding. Unintentional islanding of PVPCS may result in power-quality issues, interference to grid-protection devices, equipment damage, and even personnel safety hazards. Therefore the verification of anti-islanding performance is strongly needed. In this paper, improved RPV method is proposed through considering power quality and anti-islanding capacity of grid-connected single-phase PVPCS in IEEE Std 1547 ("Standard for Interconnecting Distributed Resources to Electric Power Systems"). And the simulation results are verified.

• Journal of the Korean Institute of Gas
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• v.25 no.5
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• pp.78-87
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• 2021

This paper analyzes the range and attributes of the traffic information service between domestic public institutions and private companies, and suggests the possibility of joint application of node-link information for each company and the possibility of joint use of private traffic information. For this purpose, the present condition and attributes of domestic and foreign traffic information node-links (link length, node ID number, U-turn information, lane information, left turn information, right turn information, etc.) were analyzed. The analysis targets, the node-link of the national standard node and the two companies were analyzed. The area of the experiment was selected in Jongno-gu, Seoul, where standard-link information is complex, traffic volume is high, and various standard-links exist. The experiment was conducted by comparing and analyzing the traffic information attributes of three types of node-links and performing node-links overlapping matching (utilizing encoding_decoding method), and the possibility of matching node-links and attributes of different specifications was analyzed using Open LR technique.

• Science of Emotion and Sensibility
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• v.11 no.4
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• pp.501-510
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• 2008

The purpose of this study was to investigate whether the orientation of the head position across different categories affect reaction time and accuracy of object recognition. Fifty four right handed undergraduate students were participated in the experiment. Participants performed the word-picture matching tasks, which were different in terms of head direction of object (i.e., Left-headed or Right-headed) and object category (i.e., natural : animal or artificial : tool). Participants were asked to decide whether each picture matched the word which was followed by the picture. For accuracy, no statistically significant difference was found for both animal and tool pictures due to the ceiling effect. Interaction effect of category and orientation were statistically significant, whereas only the main effect of category was significant. In the animal condition, faster reaction times were observed for left to right than right to left presentation, while no statistical significant difference was found in the tool condition. The orientation of the object's canonical representation was different across different categories. The faster RT for the animal condition implies that the canonical representation for animal is left-headed. This could be due to the orientation of the face.