• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.7 s.361
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• pp.24-30
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• 2007

Latching optical switches and optical logic gates with AND or OR, and the INVERT functionality are demonstrated, for the first time, by the monolithic integration of a differential typed vertical cavity laser with depleted optical thyristor (VCL-DOT) structure with a low threshold current of 0.65 mA, a high slope efficiency of 0.38 mW/mA, and high sensitivity to input optical light. Many kinds of logic functions (AND, OR, NAND, NOR, and INVERT) are experimentally demonstrated using a differential switching operation scheme changing the intensity of a reference input beam without any changes of electrical circuits.

• Journal of the Korea Society of Computer and Information
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• v.19 no.5
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• pp.27-35
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• 2014

The characteristics of today's health care industry, based on the state of the art IT can be represented as a paradigm of human-oriented ubiquitous and accessible as possible by U-Health care. In addition, the healthcare industry is information and communication technologies (ICT) developments regarding the many advances and applications based on the research being carried out actively. Medical information system has been developed toward combining information systems of medical IT and it sets its sights on the fusion of developed IT and u-healthcare system. So changing distributed medical information systems into a safe PHR integrated system based on IaaS cloud computing is suggested in order to forge u-healthcare system with the times in this paper. Our experimental results show that our proposed system increased the data access time by about 24% and reduces the waiting time for processing service by about 4.3% over the web-based PHR.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.4
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• pp.297-303
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• 2014

Using the bond-based peridynamics and the parallel computation with binary decomposition, an adjoint shape design sensitivity analysis(DSA) method is developed for the dynamic crack propagation problems. The peridynamics includes the successive branching of cracks and employs the explicit scheme of time integration. The adjoint variable method is generally not suitable for path-dependent problems but employed since the path of response analysis is readily available. The accuracy of analytical design sensitivity is verified by comparing it with the finite difference one. The finite difference method is susceptible to the amount of design perturbations and could result in inaccurate design sensitivity for highly nonlinear peridynamics problems with respect to the design. It turns out that $C^1$-continuous volume fraction is necessary for the accurate evaluation of shape design sensitivity in peridynamic discretization.

• Convergence Security Journal
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• v.5 no.1
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• pp.19-27
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• 2005

This paper presents the content regarding electronic medical examination chart and data processing for efficient medical examination and fast treatment by realizing remote medical examination system of mutual conversation type among 3 parties(patient, doctor, pharmacist) on internet base, and establishment of database enabled system integration for efficient data processing in both on-line and off-line mode by interconnecting ASP and SQL on IIS 4.0 web server, consultation between patient and doctor, medical examination on off-line mode, transmission of prescription sheet to the pharmacist designated by patient, preparation of medicine, semieternal storage of medical examination data owing to storage and check of medical examination data, more accurate medical examination and prescription using this medical examination data by patient and doctor, and so on. And, data processing between doctor and pharmacist is differently performed based on class such as general member and charge member, and service access right pursuant to this is endowed, so that certification of each member must follow by all means.

• Journal of Electrical Engineering and Technology
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• v.13 no.4
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• pp.1459-1473
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• 2018

This paper focuses on voltage control schemes for multi-terminal low-voltage direct current (LVDC) distribution systems. In a multi-terminal LVDC distribution system, there can be multiple AC/DC converters that connect the LVDC distribution system to the AC grids. This configuration can provide enhanced reliability, grid-supporting functionality, and higher efficiency. The main applications of multi-terminal LVDC distribution systems include flexible power exchange between multiple power grids and integration of distributed energy resources (DERs) using DC voltages such as photovoltaics (PVs) and battery energy storage systems (BESSs). In multi-terminal LVDC distribution systems, voltage regulation is one of the most important issues for maintaining the electric power balance between demand and supply and providing high power quality to end customers. This paper focuses on a voltage control method for multi-terminal LVDC distribution system that can efficiently coordinate multiple control units, such as AC/DC converters, PVs and BESSs. In this paper, a control hierarchy is defined for undervoltage (UV) and overvoltage (OV) problems in LVDC distribution systems based on the control priority between the control units. This paper also proposes methods to determine accurate control commands for AC/DC converters and DERs. By using the proposed method, we can effectively maintain the line voltages in multi-terminal LVDC distribution systems in the normal range. The performance of the proposed voltage control method is evaluated by case studies.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.6 no.1
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• pp.131-146
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• 2012

As one of the four basic technologies of IOT (Internet of Things), M2M technology whose advance could influence on the technology of Internet of Things has a rapid development. Mobile Payment is one of the most widespread applications in M2M. Due to applying wireless network in Mobile Payment, the security issues based on wireless network have to be solved. The technologies applied in solutions generally include two sorts, encryption mechanism and authentication mechanism, the focus in this paper is the authentication mechanism of Mobile Payment. In this paper, we consider that there are four vital things in the authentication mechanism of Mobile Payment: two-way authentication, re-authentication, roaming authentication and inside authentication. Two-way authentication is to make the mobile device and the center system trust each other, and two-way authentication is the foundation of the other three. Re-authentication is to re-establish the active communication after the mobile subscriber changes his point of attachment to the network. Inside authentication is to prevent the attacker from obtaining the privacy via attacking the mobile device if the attacker captures the mobile device. Roaming authentication is to prove the mobile subscriber's legitimate identity to the foreign agency when he roams into a foreign place, and roaming authentication can be regarded as the integration of the above three. After making a simulation of our proposed authentication mechanism and analyzing the existed schemes, we summarize that the authentication mechanism based on the mentioned above in this paper and the encryption mechanism establish the integrate security framework of Mobile Payment together. This makes the parties of Mobile Payment apply the services which Mobile Payment provides credibly.

• Journal of the Earthquake Engineering Society of Korea
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• v.8 no.2
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• pp.19-25
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• 2004

The linear analysis for the balance of linear momentum of a structure is relatively easy to perform, but the error becomes large when the structure experiences large deformation. Therefore, the material and geometric nonlinearity need to be considered for the precise calculations in that case. The plastic flow of a ductile steel-like metal mainly transforms its dissipated mechanical energy into heat, which transfers under the first and second law of thermodynamics. This heat increases the temperature of the material and the strength of the material decreases accordingly, which affects mechanical behavior of the given structure. This paper presents a finite-strain thermo-elasto-plastic steel model. This model can handle large deformation and thermal load simultaneously, which is common during earthquake periods. Two 3-dimensional finite element analyses verify this formulation.

• Korean Journal of Remote Sensing
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• v.20 no.4
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• pp.235-244
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• 2004

This study focuses on the assessment for proposed algorithm to discriminate cloudy pixels from snowy pixels through use of visible, near infrared, and short wave infrared channel data in VEGETATION-1 sensor embarked on SPOT-4 satellite. Traditional threshold algorithms for cloud and snow masks did not show very good accuracy. Instead of these independent masking procedures, K-Means clustering scheme is employed for cloud/snow discrimination in this study. The pixels used in clustering were selected through an integration of two threshold algorithms, which group ensemble the snow and cloud pixels. This may give a opportunity to simplify the clustering procedure and to improve the accuracy as compared with full image clustering. This paper also compared the results with threshold methods of snow cover and clouds, and assesses discrimination capability in VEGETATION channels. The quality of the cloud and snow mask even more improved when present algorithm is implemented. The discrimination errors were considerably reduced by 19.4% and 9.7% for cloud mask and snow mask as compared with traditional methods, respectively.

• Journal of Digital Convergence
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• v.17 no.10
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• pp.433-438
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• 2019

In this paper, the write analysis the application of basic video content of Mobil Device Platform in China and studies the future development scheme. According to the survey, as of 2019, 78% of Chinese total population is the Internet service users and application software users. Mobile Device Platform is independently developed to provide video content application services, which already have 640 million video application users from 2013 to the present. 65% of users install and use more than two video content applications. In China TikTok, Kuai Shou, MeiPai and other video content applications, not only can easily achieve simple user interface and users can directly shoot video content. These production functions is different from YouTube, a famous video platform in the United States. In the video platform market, the core competitiveness is content creation. In the future, the integration of video content of VR, AR and other video projects will expecte to further activate the video platform market.

• Korean Journal of Heritage: History & Science
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• v.49 no.4
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• pp.156-179
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• 2016

Yatsushiro Shrine on the island of Kamishima located in Ise Bay, Japan, contains many cultural artifacts with ancient mirrors in significant numbers. Also included among the artifacts are horse gags and reins that are clearly of the same lineage as the horse harnesses from the unified Shilla era and Goryeo era in Korean history. Type classification and position establishment were carried out on the horse reins kept in the Yatsushiro shrine, including items such as those mentioned previously. Type A horse harness can be classified into 3 types. Based on this classification scheme, the harness type in the Yatsushiro shrine was found to belong to the most recent period. The blacksmith workshop that made the harness was producing iron wares and bronze wares, and it possessed metal forging and metal casting technologies. Note, however, that it was primarily a workshop where iron wares were made. The parts that were visible from the outside when the harness was attached were made from composite bronze, and the reins and bridle linkage were made from iron. Such integration of bronze ware production techniques and iron ware production techniques was an attempt at enhancing the practicality and embellishments on the harness.