• ETRI Journal
• /
• v.42 no.2
• /
• pp.163-174
• /
• 2020

Numerous wearable technology companies have recently developed several headmounted display (HMD) products for virtual reality (VR) services. 5G wireless networks aim at providing high-quality 3D multimedia services such as VR, augmented reality, and mixed reality. In this study, we examine the application of millimeter-wave (mmWave) technology to realize low-latency wireless communication between an HMD and its content server. However, the propagation characteristics of mmWave present several challenges such as the deafness, blockage, and beam alignment problems, and interference among content servers. In this study, we focus on an environment that provides VR services in the mmWave band and introduce existing techniques for addressing such challenges. In addition, we employ a commercialized IEEE 802.11ad VR dongle to measure the actual data rate of an mmWave VR application and identify the degree to which the performance deteriorates when the above problems occur. Finally, we verify the feasibility of the proposed solutions through a simulation of several VR scenarios in the mmWave band.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.25 no.3
• /
• pp.322-329
• /
• 2001

A study of the shock wave turbulent boundary layer interaction is presented. The focus of the study is the interactions of the shock waves with the turbulent boundary layer on the falt plate. Three examples are investigated. The computations are performed, using mixed explicit-implicit generalized Galerkin finite element method. The linear equations at each time step are solved by a preconditioned GMRES algorithm. Numerical results indicate that the implicit scheme converges to the asymptotic steady state much faster than the explicit counterpart. The computed surface pressures and skin friction coefficients display good agreement with experimental data. The flowfield manifests a complex shock wave system and a pair of counter-rotating vortices.

• Geophysics and Geophysical Exploration
• /
• v.5 no.2
• /
• pp.93-98
• /
• 2002

A three dimensional model for the orebody of an operating mine in Korea was constructed by using a program called '3-D Modeler'. The program allows the user to interactively construct a 3-D model of an orebody from its horizontal cross-sections. The 3-D Modeler is easily able to combine and display various spatial data for model construction. The result of modeling is strongly influenced by control points that correlate to the adjacent horizontal cross-sections. The control points are determined by comparing the geometrical shape of the adjacent cross-sections in conjunction with the geological features of the orebody. The resulting model can be evaluated in viewing the constructed object in three dimensional space or more closely evaluated by inspecting the cross-section. The model can iteratively be improved by modifying the shape of the cross-section and by using this new cross-section for the model building.

• IEIE Transactions on Smart Processing and Computing
• /
• v.4 no.4
• /
• pp.224-230
• /
• 2015

This manuscript presents a real-time solution for 3D human body reconstruction with multiple RGB-D cameras. The proposed system uses four consumer RGB/Depth (RGB-D) cameras, each located at approximately $90^{\circ}$ from the next camera around a freely moving human body. A single mesh is constructed from the captured point clouds by iteratively removing the estimated overlapping regions from the boundary. A cell-based mesh construction algorithm is developed, recovering the 3D shape from various conditions, considering the direction of the camera and the mesh boundary. The proposed algorithm also allows problematic holes and/or occluded regions to be recovered from another view. Finally, calibrated RGB data is merged with the constructed mesh so it can be viewed from an arbitrary direction. The proposed algorithm is implemented with general-purpose computation on graphics processing unit (GPGPU) for real-time processing owing to its suitability for parallel processing.

• Journal of the Optical Society of Korea
• /
• v.20 no.5
• /
• pp.586-592
• /
• 2016

This paper proposes a luminance compensation method using optical sensors to achieve high luminance uniformity of active matrix organic light-emitting diode (AMOLED) displays. The proposed method compensates for the non-uniformity of luminance by capturing the luminance of entire pixels and extracting the characteristic parameters. Data modulation using the extracted characteristic parameters is performed to improve luminance uniformity. In addition, memory size is optimized by selecting an optimal bit depth of the extracted characteristic parameters according to the trade-off between the required memory size and luminance uniformity. To verify the proposed compensation method with the optimized memory size, a 40-inch 1920×1080 AMOLED display with a target maximum luminance of 350 cd/m² is used. The proposed compensation method considering a 4σ range of luminance reduces luminance error from ± 38.64%, ± 36.32%, and ± 43.12% to ± 2.68%, ± 2.64%, and ± 2.76% for red, green, and blue colors, respectively. The optimal bit depth of each characteristic parameter is 6-bit and the total required memory size to achieve high luminance uniformity is 74.6 Mbits.

• The Research Journal of the Costume Culture
• /
• v.10 no.2
• /
• pp.116-131
• /
• 2002

The purposes of this study were to analyze the lifestyle of women in their 50's and 60's and to provide the basis for the efficient strategy of silver market by classifying women in their 50's and 60's according to lifestyle types and investigating the effect of consumers' lifestyle and demographic characteristics on consumers' clothing buying motived and information sources. In this study, a self-administered questionnaire was distributed to women in their 50's and 60's. 226 questionnaires of 350 were used in the following analysis. The data were analyzed with the SPSS package. The results of this study were as follows. First, lifestyle were analyzed to find out the underlying factors, and then the subjects were grouped according to factor scores by the cluster analysis. Four lifestyle types were defined. They were the traditional family-oriented, the ostentatious purchase, the economical material-oriented, the active economics-oriented type. Second, a consumer's buying motives and information sources in buying clothing were significantly different depending on the consumer's lifestyle. The ostentatious purchase type attached importance to impulse buying and in diversion in clothing buying motives and display in information sources. The economical material-oriented type tend to buy clothes to purchase economically during bargain sales. The active economics-oriented type attached importance to worn out clothing in buying motives.

• Journal of Korea Society of Industrial Information Systems
• /
• v.20 no.4
• /
• pp.103-109
• /
• 2015

This paper presents the development of a ROM writer for shmoo test of a flash memory integrated into the MCU(Micro Controller Unit). A shmoo test is a graphical display of the response of a component or system varying over a range of conditions and inputs. Often used to represent the results of the testing of complex electronic systems such as computers or integrated circuits such as DRAMs, ASICs or microprocessors. A shmoo test and data write time(32k) of the development ROM writer is 6.4 seconds, which was improved by about 20% compared to the rate of the currently used ROM writer.

• Journal of the Korean Society for Aviation and Aeronautics
• /
• v.23 no.3
• /
• pp.28-34
• /
• 2015

An analysis method of trajectory prediction has been suggested and the developed trajectory prediction module, which is an important functional component of the Arrival Manager (AMAN) of Jeju airport, has been tested by applying the suggested method. The objective of this method is to improve prediction performance of the trajectory prediction module. The trajectory prediction module predicts the trajectories based on the real-time track data and flight plans. Therefore, the suggested analysis method includes the simulation framework which is based on real-time playback, recording, and graphic display systems for testing. Besides, the definition of time error, which is a important index for the time based scheduling system, such as AMAN, is included in the suggested analysis method. An example of arrival time prediction accuracy improvement through the suggested analysis method has also been presented.

• Journal of Home Health Care Nursing
• /
• v.23 no.2
• /
• pp.139-146
• /
• 2016

Purpose: This research seeks to identify differences between general characteristics, disease-related characteristics, glycated hemoglobin (HbAlc) levels, and aspects of chronic complications of diabetes mellitus in type 2 diabetes. Methods: This research was conducted from the 1st to the 15th of February in 2016, on 263 in patients. Patients' electronic medical records were used to identify their general characteristics, disease-related characteristics, HbAlc, and chronic diabetic complications. Chi-square test, ANOVA, ANCOVA, and the Cochran-Mantel-Haenszel test were used for data analysis. Results: Statistical significance was observed for general characteristics, based on smoking status, such as age, and education level; disease-related characteristics differed according to the duration of diabetes. Smoking status did not differ according to HbAlc level. In term of chronic diabetic complications, statistically significance was observed for diabetic nephropathy, based on smoking status. Conclusion: Patients who had a history of smoking, but were not currently smoking, were likely to display higher HbAlc levels and diabetic nephropathy. Therefore, there is need for regular checkups for diabetic complications among patients with a history of smoking and it is important to emphasize smoking cessation.

• Journal of the Korea Fashion and Costume Design Association
• /
• v.16 no.2
• /
• pp.55-70
• /
• 2014

The purpose of this study was to investigate purchasing behaviors of summer clothes using cooling textiles and clothing design preference in summer season. The subjects were 623 married women aged from 30s to 60s. The research method was a survey and the measuring instruments consisted of purchasing behaviors of summer clothes using cooling textiles, clothing design preference in summer season, and subjects' demographics attributions. The data were analyzed by frequency analysis, multiple response analysis, cross tabs analysis, and $x^2$ test, using SPSS statistical program. The results were as follows. First, important clothing selection criteria were design, price, and textiles. The main items using cooling textiles that female consumers purchased were T-shirts, pants, and outdoor & sportswear. Main information sources of summer clothes using cooling textiles were internet and store display, and purchasing places were fashion outlet, internet, brand store, and department store. Second, female consumers most preferred comfortable and casual style. They mainly preferred white and blue color, pastel and pale tone, plain pattern, and cotton and functional materials in summer season. Third, there were many important differences among 4 age groups on purchasing behaviors of summer clothes using cooling textiles and design preference in summer season.