• Korean Chemical Engineering Research
• /
• v.54 no.1
• /
• pp.44-51
• /
• 2016

The powder core, conventionally fabricated from iron particles coated with insulator, showed large eddy current loss under high frequency, because of small specific resistance. To overcome the eddy current loss, the increase in the specific resistance of powder cores was needed. In this study, copper oxide coating onto electrically conductive iron particles was performed using a planetary ball mill to increase the specific resistance. Coating factors were optimized by the Response surface methodology. The independent variables were the CuO mass fraction, mill revolution number, coating time, ball size, ball mass and sample mass. The response variable was the specific resistance. The optimization of six factors by the fractional factorial design indicated that CuO mass fraction, mill revolution number, and coating time were the key factors. The levels of these three factors were selected by the three-factors full factorial design and steepest ascent method. The steepest ascent method was used to approach the optimum range for maximum specific resistance. The Box-Behnken design was finally used to analyze the response surfaces of the screened factors for further optimization. The results of the Box-Behnken design showed that the CuO mass fraction and mill revolution number were the main factors affecting the efficiency of coating process. As the CuO mass fraction increased, the specific resistance increased. In contrast, the specific resistance increased with decreasing mill revolution number. The process optimization results revealed a high agreement between the experimental and the predicted data ($Adj-R^2=0.944$). The optimized CuO mass fraction, mill revolution number, and coating time were 0.4, 200 rpm, and 15 min, respectively. The measured value of the specific resistance of the coated pellet under the optimized conditions of the maximum specific resistance was $530k{\Omega}{\cdot}cm$.

• Korean Journal of Construction Engineering and Management
• /
• v.15 no.5
• /
• pp.138-146
• /
• 2014

Modular construction is one of the arising issues in the Korean construction industry due to shorter construction period and higher productivity on site. It is also expected that modular construction market would expand rapidly because of increasing demand of small houses by nuclear families and eco-friendly construction. However modular construction cases have been limited in Korea because of little demand in the market and the construction prices are even higher that the regular reinforced concrete methods. Even worse, because there is no standard bill of services exists in the industry, it may lead to the risk of construction expenses. So, the purpose of this study is focused on the development of bill of services which reflects characteristics and process of modular construction. In order to do this, the concepts and process of modular construction, WBS and CBS are analyzed. Analyses of the case studies and experts interview were executed so that proper principles for organizing bill of service of modular construction is established. Finally according to the 3 steps of modular construction, factory manufacturing, on-site modular construction and on-site general construction, the standard bill of services were suggested with the related coding system.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.19 no.4
• /
• pp.169-185
• /
• 2016

Recently mean stand height has been added as new attribute to forest type maps, but it is often too costly and time consuming to manually measure 9,100,000 points from countrywide stereo aerial photos. In addition, tree heights are frequently measured around tombs and forest edges, which are poor representations of the interior tree stand. This work proposes an estimation of mean stand height using an image-based point cloud, which was extracted from stereo aerial photo with FUSION S/W. Then, a digital terrain model was created by filtering the DSM point cloud and subtracting the DTM from DSM, resulting in nDSM, which represents object heights (buildings, trees, etc.). The RMSE was calculated to compare differences in tree heights between those observed and extracted from the nDSM. The resulting RMSE of average total plot height was 0.96 m. Individual tree heights of the whole study site area were extracted using the USDA Forest Service's FUSION S/W. Finally, mean stand height was produced by averaging individual tree heights in a stand polygon of the forest type map. In order to automate the mean stand height extraction using photogrammetric methods, a module was developed as an ArcGIS add-in toolbox.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.48 no.1
• /
• pp.15-24
• /
• 2020

This work examines discourse on uses of computer technology and its transformation during the last thirty years effecting Korea landscape architecture. First, in the 1990s landscape architects begun to use computers as a new technology for landscape architecture, programming computer software utilities suitable for landscape research, planning, and design. The landscape architects, acting as computer programmers, tried to explore various techniques for landscape analysis and design with a piece of software, and various experts within the field of landscape architecture collaborated with each other. However, landscape architects mainly used computer technology as a tool as a substitute for hands-on cases. Since around the 2000s, the discourse on mapping and diagrammatic techniques as a visualization technique for landscaping processes have begun. Also, realistic representations for perspective drawings using graphic software have been increasingly important. The landscape architects, acting as graphic designers, focused on the specific visualization techniques for landscape planning and design. However, computer technology has been mainly used to produce realistic visuals aids for final presentations instead of creative exploration to generate landforms. Additionally, recent landscape architects have been using landscape performance modeling and parametric modeling for landform and landscape furniture design. The landscape architects as spatial designers are actively using computer modeling as creative form-generating tools during the design process.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.12 no.1
• /
• pp.1-11
• /
• 2009

Rapid visualization of flood area of downstream according to the dam effluent in flood season is very important in dam management works. Overlay zone of river bight should be removed to represent flood area efficiently based on flood stage which was modeled in river channels. This study applied drainage enforcement algorithm to visualize flood area considering river bight by coupling Coordinate Operation System for Flood control In Multi-reservoir (COSFIM) and Flood Wave routing model (FLDWAV). The drainage enforcement algorithm is a kind of interpolation which gives to advantage into hydrological process studies by removing spurious sinks of terrain in automatic drainage algorithm. This study presented mapping technique of flood area layer considering river bight in Namgang-Dam downstream, and developed system based on Arcobject component to execute this process automatically. Automatic extraction system of flood area layer could save time-consuming efficiently in flood inundation visualization work which was propelled based on large volume data. Also, flood area layer by coupling with IKONOS satellite image presented real information in flood disaster works.

• Korean Journal of Construction Engineering and Management
• /
• v.17 no.2
• /
• pp.135-145
• /
• 2016

In Korea, a series of noise-reduced aluminum forms are being recently used in apartment housing construction. However, their complicated and time-consuming work processes, and the noise which is still generated due to the inherent property of aluminum when especially installing and dismantling them have been pointed out as a problem to be certainly solved for increasing their practical use in construction sites. The primary objectives of this study are proposing an optimal conceptual design of a newly designed noise-reduced aluminum form and verifying the technical feasibility by conducting a working mock-up drive experiment. Thus, conventional noise-reduced aluminum forms have been analyzed and three conceptual designs of a newly noise-reduced aluminum forms have been deducted. AHP has been applied to a survey data collected by interviewing field experts. A trade-off analysis results have shown that 'Noise-reduced System Aluminum Form with a Drop-down Floor Post and Adaptive Beam' the highest weights of safety(0.52), work convenience(0.54) and thus selected. The suggested conceptual design in this study improved problems of conventional system aluminum forms. It is also expected that the suggested design will be used as a reliable guideline for the actual development of an aluminum form that ensures noise-reduce, work convenience and labor safety.

• Journal of Korea Multimedia Society
• /
• v.10 no.10
• /
• pp.1310-1318
• /
• 2007

First of all, What was the modeling technique used to model 3D-Game character? It's a technique developed along several years, by experience... here is the bases Low polygons characters I always work in low polygon for two reasons -You can easily modify a low-poly character, change shapes, make morph for facial expressions etc -You can easily animate a low-poly character When the modeling is finished, Second, In these days, Computer hardware technologies have been bring about that expansion of various 3D digital motion pictured information and development. 3D digital techniques can be used to be diversity in Animation, Virtual-Reality, Movie, Advertisement, Game and so on. Besides, as computing power has been better and higher, the development of 3D Animations and Character are required gradually. In order to satisfy the requirement, Research about how to make 3D Game modeling that represents Character's emotions, sensibilities, is beginning to set its appearance. 3D characters in 3D Games are the core for the communications of emotion and the informations through their facial expression and characteristic motions, Sounds to Users. All concerning about 3D motion and facial expression are getting higher with extension of frequency in use. Therefore, in this study we suggest the effective method of modeling for 3D character and which are based on 2D Graphics.

• Journal of the Korean Institute of Gas
• /
• v.14 no.5
• /
• pp.13-18
• /
• 2010

This paper presents the development of an integrated control and safety management system for 9% nickel steel LNG storage tank. The new system added the measuring equipment of pressure, displacement and force compared to the conventional measurement and control system. The measured data has simultaneously been processed by integrating and analyzing with new control equipments and safety management systems. The integrated control and safety management system, which may increase a safety and efficiency of a super-large full containment LNG storage tank, added additional pressure gauges and new displacement/force sensors at the outer side wall and a welding zone of a stiffener and top girder of an inner tank, and the inner side wall of a corner protection tank. The displacement and force sensors may provide failure clues of 9% nickel steel structures such as an inner tank and a corner protection, and a LNG leakage from the inner tank. The conventional leak sensor may not provide proper information on 9% nickel steel tank fracture even though LNG is leaked until the leak detector, which is placed at the insulation area between an inner tank and a corner protection tank, sends a warning signal. Thus, the new integrated control and safety management system is to collect and analyze the temperature, pressure, displacement, force, and LNG density, which are related to the tank system safety and leakage control from the inner tank. The digital data are also measured from control systems such as displacement and force of 9% nickel steel tank safety, LNG level and density, cool-down process, leakage, and pressure controls.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
• /
• v.11 no.1
• /
• pp.34-39
• /
• 2018

Along with the development of ICT technology, wearable devices of various sizes and shapes have been developed. In addition, performance and specifications are rebuilt with IOT fusion products so that they can connect with the current smartphone. This is one of the general-purpose technologies of the 4th industrial revolution, which is spot-lighted with technology that changes the quality and environment of our lives. Along with this, as new technology products combining health care technology increases, various functions are provided to users who need it. Wearable technology is ongoing trend of technology development. It also sells products developed as products in the form of smart watches. At present, various related products are made in various ways, and it is recommended to use the Arduino processor in accordance with the application. In this study, we developed wearable physical activity monitoring system using open source hardware based TinyDuino. TinyDuino is an ultra-compact Arduino compatible board made on the basis of Atmega process Board, and it can be programmed in open source integrated development environment(named Sketch). The physical activity monitoring system of the welfare body can be said to be a great advantage, as a smart u-Healthcare system that can perform daily health management.

• Analytical Science and Technology
• /
• v.31 no.2
• /
• pp.65-70
• /
• 2018

This study compared two methods for preparing ancient DNA (aDNA) for the construction of successful shotgun libraries that may be applied to massive parallel sequencing. For the comparative analysis, the DNA of prehistoric rib samples from Hungary was extracted using either a manually prepared silica suspension or the Amicon Ultracel-15 10K ultracentrifugal device (Millipore). After the extraction of the same amount of bone powder (about 150 mg) from three samples by each method, the amount of extracted double-stranded DNA and the subsequent degree of construction of the shotgun library were analyzed. The Amicon device method was rapid and easier to perform and resulted in an approximately 11-fold higher DNA recovery than that obtained using the silica suspension. The shotgun library constructed using DNA templates prepared by the Amicon device was more successful than that constructed from templates isolated using the silica suspension. The comparative study of these two aDNA extraction methods showed that the Amicon device has the advantages of saving time, process simplicity, and high efficiency.