• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.8
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• pp.1456-1464
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• 2007

The research of skin-tone detection has been conducting continuously to enlarge the importance in security, surveillance and administration of the information and 'Password Control System' for using face and skin recognition in airports, harbors and general companies. As well as tile rapid diffusion of the application range in image communications and an electron transaction using wide range of communication network, the importance of the accurate detection of skin color has been augmenting recently. In this paper, it will set up the boundaries of skin colors using the information of Cb and Cr in YCbCr color model of human skin color which is from hundreds compiled portrait images for each race, and suggest a efficient yet simple structure about the skin detection which has been followed by whether the comprehension of the boundaries of skin or not with adaptive skin-range set. With the possibility of the 1D Processes which does not use any memory, it is able to be applied to relatively small-sized hardware and system such as mobile apparatuses. To add the selective mode, it is not only available the improvement of tie skin detection, but also showing the correspondent results about previous face recognition technologies using complicated algorithm.

• FLOWER RESEARCH JOURNAL
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• v.16 no.1
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• pp.1-6
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• 2008

This study investigated the changes of indoor thermal environment by Ardisia species planted in indoor space. Three Ardisia species (Ardisia japonica, Ardisia crenata and Ardisia pusilla) were used in this study and differences of temperature and relative humidity were ascertained in an empty chamber with and without plants. In high temperatures over $24^{\circ}C$, Ardisia species cooled down chamber more as compared to the control without plants, but there were no significant differences among Ardisia species. Ardisia crenata showed high relative humidity of $57.3{\pm}3.1%$ during most of the day time and $60.8{\pm}2.5%$ at low temperatures. However, Ardisia japonica and Ardisia pusilla showed $54.7{\pm}1.18%$ and $52.5{\pm}2.4%$, respectively, on the average, and they maintained comfortable relative humidity during most of the day time. When the setting temperature was decreased from 28 to $26^{\circ}C$, Ardisia species showed 7.5~13.6 times greater cooling efficiency as compared to the control without plants, and at low temperatures the chamber without plants showed higher themal energy than the chamber with plants. Ardisia species were effective on cooling down the temperature at high temperatures and they showed a tendency to maintain proper temperatures at low temperatures.

• Korean Journal of Optics and Photonics
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• v.30 no.5
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• pp.193-196
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• 2019

The design and control of thermal flow is important for the operation of high-power laser diodes (LDs). It is necessary to analyze and improve the thermal bottleneck near the active layer of an LD. As the error in prediction of the thermal resistance of an LD is large, typically due to the hyperbolic increase and saturation to linear increase of the thermal resistance as a function of thickness, it is helpful to use a simple, modified divergence model for the improvement and optimization of thermal resistance. The characteristics of LDs are described quite well, in that the values for simulated thermal resistance curves and the thermal cross section followed are almost the same as the values from the model function. Also, the thermal-cross-section curve obtained by differentiating the thermal resistance is good for identifying thermal bottlenecks intuitively, and is also fitted quite well by the model proposed for both a typical LD structure and an improved LD with thin capping and high thermal conductivity.

• Applied Chemistry for Engineering
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• v.30 no.5
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• pp.546-555
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• 2019

The purpose of this study was to improve the performance of the bogie-type crematory, which is the mainstream of domestic crematory equipment. A field scale technology was investigated via increasing the volume by changing the shape of the furnace and reducing the cremation time and saving the energy usage through the optimization of burner combustion control. First, the optimized structural design through thermal flow analysis increases the volume of the main combustion chamber by about 70%, which increases the residence time of the combustion flue gas. A designed pilot crematory was then installed and the combustion behavior was tested under various operating conditions and the optimum operating plan was derived from for each furnace shape. Based on the results, the practically applicable crematory was designed and installed at Y crematorium in the P City. Optimal combustion conditions could be derived through operating the demonstration crematory furnace. The crematory time and fuel consumption could be minimized by increasing the energy efficiency by increasing the residence time of high temperature combustion flue gas. In other words, the crematory time and fuel consumption were 38 min and $21.8Nm^3$, respectively which were shortened by 44.1 and 54.4% lower than that of the existing crematory, respectively.

• Bulletin of the Society of Naval Architects of Korea
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• v.6 no.1
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• pp.25-34
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• 1969

From viewpoints of over-all ship economy the straight framed V-bottom hull forms with chines are considered to be attractive even for usual commercial vessels, because increments of resistance over that of round hull forms, if any, can be well compensated with reduction in construction cost.[1] To investigate the influences of both prismatic coefficient and chine elevation on resistance performance, three models of straight-framed V-bottom hull forms which are similar to Prof. C. Ridgely-Nevitt's W-18, W-8, and W-20[2],[3] in size and hull form coefficients were tested at the SNU Ship Model Towing Tank for resistance measurements. They are of Cp=0.60, 0.65 and 0.70 and of ${\Delta}/(0.01L)^3=300$. Influence of variation of chine elevation on resistance performance were observed with the test results obtained at normal condition, and at the trimed by the stern by 2% and 4% of $L_{bp}$ at normal condition under same displacement. The hull form characteristics are shown in Table 1, and in Fig. 1, 2, 3, 4 and 5. The test results are shown in Fig 8, 9 and 10 in the form of Cr vs. $V/\sqrt{L}$ curves taking Cp as a parameter for normal condition, trim by the stern in 2% and 4% $L_{bp}$ at normal condition , respectively. Cr vs. $V/\sqrt{L}$ curves taking trim condition as a parameter are also shown in Fig 11, 12 and 13 for Cp=0.60 and 0.70, respectively. The best and the worst trim condition at given $V/\sqrt{L}$ in viewpoint of Cr are plotted for each Cp-value as shown in Fig 14, 15 and 16. From the above results the following conclusions are derived: (1) In general, the resistance performance of the straight-framed V-bottom hull forms are not inferior to those of round hull forms. At a certain range of $V/\sqrt{L}$ the former gives less resistance than the latter. (2) Regarding influences of Cp on Cr, it is observed that, at $V/\sqrt{L}$ less than about 0.925, the greater Cp-value gives the more increment of Cr, and that, at $V/\sqrt{L}$ greater than about 0.925 the smaller Cp-value gives the more increment of Cr. It is also noteworthy that the model of Cp=0.70 has remarkable hump on Cr vs. $V/\sqrt{L}$ curve between $V/\sqrt{L}=0.80$ and 0.90. (3) For higher speed within the test range, the chine elevation having the steeper slope around bow and the easier slope around amidship and stern, refered to watering, give the better results in resistance performance. (4) Assuming the chine elevations adopted for the tested models were not of the best, we would expect further improvement of resistance performance for such form. Hence, a systematic study on chine elevation is very disirable to prepare design data of general purpose for the such hull forms.

• Bulletin of the Society of Naval Architects of Korea
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• v.27 no.3
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• pp.89-99
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• 1990

It is required to develop a hull form with low resistance and high propulsive efficiency for the improvement of the ship-board operational economy. Since the hull forms with low resistance frequently have lower propulsive efficiency and on the other hand the hull forms with higher propulsive efficiency don't show good resistance characteristics, it is always very difficult to obtain economical hull forms which require less propulsive power accordingly. Efforts have been made to pursue a stern form with excellent resistance and propulsion characteristics together by shaping the run of the so-called buttock-flow type stern, which is known to have good viscous resistance performance, like that of conventional aftbody(U-type or Hogner type) featured by high propulsive efficiency. First model tests confirmed that the above concept can be one of the alternative approaches to the design of the good stern form and by the continuing efforts thereafter for the refining of the concept, propelled by the first promising results, stern form of good resistance performance together with good propulsive efficiency has been realized to some extent. In addition, it is confirmed that the new new stern can have better cavitation and vibration characteristics due to uniform wake-fields and the compact engine room arrangement can be possible due to it's larger floor area in way of engine room double bottom as compared with usual barge stern.

• Journal of the Korea Safety Management & Science
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• v.22 no.2
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• pp.23-29
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• 2020

Korea's elevator industry is one of the world's eighth-largest industrial sectors and the third largest in the world by new installations. This year, the number of elevators has exceeded 700,000, and the number of new installations is 30,000-40,000 every year. However, the news of elevator-related accidents is reported continuously through the media and the accident rate is not decreasing. In particular, among the recent accidents related to elevators, accidents related to elevator workers are increasing, causing social problems. This year, the National Assembly's Environmental Labor Relations Commission's National Auditors lost five lives a year and 12 elevator workers were killed in fall and stenosis accidents during the installation, maintenance and replacement of the elevators for about two years since 2018. It took place to adopt the representatives of four domestic elevator companies as witnesses. An elevator worker is a collective term for workers involved in the design, manufacturing, installation, replacement, maintenance, inspection, management, and supervision related to the elevator industry, and the related accidents are called elevator worker accidents. Analysis of elevator-related accidents in the past has shown that the fault of the user accounted for 70% of the total, and the fault of the worker accounted for about 2.5%, and the accident occurred to the user or the user due to carelessness of the worker during the lift-related work. Currently, elevator-related accidents are reported by the Korea Elevator Safety Agency under Article 48 of the Elevator Safety Management Act under the Ministry of Interior and Safety. If deemed necessary for the prevention and prevention of recurrence of an elevator accident, the cause and condition of the elevator accident may be investigated. However, the current draft law is limited only to elevators after installation inspection, and is separated from the Ministry of Employment and Labor's data on accidents occurring in the manufacturing and installation stages related to the elevator industry. This study analyzes the recent safety accidents of elevator workers and prepares safety measures to prevent them through the risk analysis, and also draws out the problems and improvements of the current elevator worker accident investigation to find the elevator worker accident rate that is on the increase trend.

• Journal of the Korean Society for Railway
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• v.18 no.6
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• pp.543-551
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• 2015

Quick-hardening track (QHT) is a construction method which is used to change from old ballast track to concrete track. Sufficient time for construction is important, as the construction should be done during operational breaks at night. Most of the time is spent on exchanging the ballast layer. If it is possible to apply the ballast non-exchange type of quick-hardening track, it would be more effective to reduce the construction time and costs. In this paper, pouring materials with high permeability are suggested and a construction method involving a layer separation pouring process considering the void condition is introduced in order to develop ballast non-exchange type of QHT. The separate pouring method can secure the required strength because optimized materials are poured into the upper layer and the lower layer for each void ratio condition. To ensure this process, a rheology analysis was conducted on the design of the pouring materials according to aggregate size, the aggregate distribution, the void ratio, the void size, the tortuosity and the permeability. A polymer series was used as the pouring material of the lower layer to secure the void filling capacity and for adhesion to the fine-grained layer. In addition, magnesium-phosphate ceramic (MPC) was used as the pouring material of the upper layer to secure the void-filling capacity and for adhesion of the coarse-grained layer. As a result of a mechanics test of the materials, satisfactory performance corresponding to existing quick-hardening track was noted.

• Journal of Aerospace System Engineering
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• v.15 no.5
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• pp.8-15
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• 2021

This paper describes a design method using an optimization technique to satisfy the longitudinal handling quality of high maneuverable jet aircraft. The dynamic inversion technique was applied to the target aircraft, and the control gain optimization satisfied the longitudinal short-period handling quality, however, the stability margin was not considered. If the stability margin is not satisfied, it is necessary to directly readjust the gains through trial and error methods for improvement. To improve this, an additional compensator and an optimization constraint were added to the control gain optimization procedure. In addition, the degree of handling quality satisfaction with the optimization result was reevaluated, and additional control evaluation criteria for the convergence of the time response and the steady state error that the flight performance requirement set as the optimization constraint cannot be reflected, and the results are described.

• Korean Journal of Construction Engineering and Management
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• v.22 no.5
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• pp.39-47
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• 2021

As domestic construction companies, which used to be concentrated in the Middle East, have expanded their overseas orders to new markets in Asia and Latin America, they have to cope with various conditions. The EPC plant project, which undertakes construction projects such as civil engineering and construction, design, purchase, construction and commissioning, has expanded its scope. As a result, it is important to collect Lessons Learned from the previous project, systematize it, and use it to respond to changes in the environment. However, many employees do not share their skills or experiences voluntarily. To do so, it is necessary to create and systematize a culture that shares experience and technology. In order to understand and analyze the current situation, a questionnaire was conducted on the EPC project-related departments of construction companies implementing the EPC plant project. About 74% of the participants said Lessons Learned's collection and utilization helped. About 53% of the people who collected and registered actual cases and 39% of the people who had experience in preventing problems using cases were identified as employees' perception and utilization of Lessons Learned systems. Detailed analysis showed differences in workplace, duties, and rank. Through this study, the current status of Lessons Learned collection and utilization of EPC plant projects is understood, and the research on collection and utilization improvement is being carried out.