• Journal of Aerospace System Engineering
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• v.8 no.2
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• pp.7-13
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• 2014

In order to enable fail-safe operation the electro-hydrostatic actuators can be dualized. When a symmetrical actuator is combined in series with an asymmetrical actuator with single rod cylinder, the flow rates of their cylinders are unmatched. If their position controller has same configuration, one of their pumps can supply too much flow rate under particular load conditions, which should be bypassed into low pressure side e.g. by a relief valve. In this paper it is shown how the hydraulic circuit for the asymmetrically combined electro-hydrostatic actuator can be designed without sacrificing power consumption.

• Journal of Auto-vehicle Safety Association
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• v.12 no.1
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• pp.15-25
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• 2020

This paper presents a longitudinal control algorithm for ensuring takeover time of autonomous vehicle using V2V communication. In the autonomous driving of more than level 3, autonomous systems should control the vehicles by itself partially. However if the driver's intervention is required for functional safety, the driver should take over the control reasonably. Autonomous driving system has to be designed so that drivers can take over the control from autonomous vehicle reasonably for driving safety. In this study, control algorithm considering takeover time has been developed based on computation method of takeover time. Takeover time is analysed by conditions of longitudinal velocity of preceding vehicle in time-velocity plane. In addition, desired clearance is derived based on takeover time. The performance evaluation of the proposed algorithm in this study was conducted using 3D vehicle model with actual driving data in Matlab/Simulink environment. The results of the performance evaluation show that the longitudinal control algorithm can control while securing takeover time reasonably.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.62-65
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• 2022

Diabetes is a major social problem in which the incidence and prevalence of diabetes increase every year around the world. Diabetes, characterized by high blood sugar, which increases the concentration of glucose in the blood, causes various symptoms and signs. As a result, patients should strengthen self-management in their daily lives. However, the biggest factor that patients fail in managing blood sugar is diet failure. Therefore, in this paper, an application was designed and implemented to input a diet through photography or image upload and analyze users' diets through intake indicators and blood sugar statistics.

• Journal of Korea Entertainment Industry Association
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• v.13 no.4
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• pp.341-348
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• 2019

The purpose of this study was to develop voluntary learning (talent donation) program as a liberal art lecture for students in G university to cultivate consideration towards others and community life. The title of the liberal education course that was developed was decided as "Beauty Talent Donation". The course objectives were to develop consideration for others and sociality required for community life as well as foster awareness of sharing and develop creative leaders equipped with outstanding characters through cosmetology voluntary service associated education. The final development of education contents were completed over 3 stages including preparation, development, and supplemented development and the major components consist of understanding talent donation, beauty theories, and beauty skills. For the assessment of the learners, absolute evaluation was applied so that personal goals can be achieved through the course instead of evaluating learners' learning capabilities with relative evaluation. Accordingly, a pass or fail system was designed. The beneficiary institution of talent donation was selected based on the following conditions. It is located within a short distance from the educational institution, walking distance for the learners, easy to recruit subjects to receive the support, and accurately understands the purpose of the lecture and willing to cooperate.

• Journal of the Institute of Electronics and Information Engineers
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• v.52 no.8
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• pp.74-85
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• 2015

PCI Express is a well-known and widely used de-facto system bus standard for connecting among a processor and IO devices. PCI Express is originated from old PCI standard, and its most of applications are limited to be used within a PC or server system. But, because of its fast speed, low power consumption, and good protocol efficiency, it is considered as one of a good candidate for an alternate system interconnect for many years. In this paper, we present design, implementation and early evaluation of an alternate system interconnect by utilizing PCI Express. The developed alternate system interconnect using PCI Express (named PCIeLINK) utilizes non-transparent bridging (NTB) technic which generally used in fail-over system in PCI and PCI Express. By using NTB technic, PCI Express device can be extended to outside of a system without electrical and logical problems arising during system boot and enumeration. To build up an alternate system interconnect, we designed and implemented a network interface card having multiple PCI Express ${\times}4$ connections (theoretically 20 Gbps) and tested, The early test results revealed that an ${\times}4$ port in the card showed 8.6 Gbps peak performance for bulk transmission and 5.1 Gbps peak for normal TCP/IP transfer.

• The Journal of the Korea Contents Association
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• v.15 no.9
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• pp.403-410
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• 2015

Since 1970, MRI has greatly been developing in terms of strength of magnetic field, the number of receipt channels, and short time of examination. With the development of digital systems and wireless network, hospitals have also acquired, saved, and managed digital images taken by various kinds of medical imaging equipment. However, domestic universities fail to provide practice training course independently thanks to expensive practice equipment and high maintenance cost, and rely on clinical training. Therefore, this study developed a MR patient diagnosis program based on Windows PC to help out students before their working in clinical filed. The designed Relational Database of MRI Simulator is made up of seven tables according to functions and data characteristics. Regarding the designed patient information, each stepwise function was classified by the patient registration method in clinical field. In addition, on the assumption of the basic information for diagnosis, each setting and content were classified. The menu by execution step was arrayed on the left side for easy view. For patient registration, a patient's name, gender, unique ID, birth date, weight, and other types of basic information were entered, and the patient's posture and diagnosis direction were set up. In addition, the body regions for diagnosis and Pulse Sequence were listed for selection. Also, Protocol name and other additional factors were allowed to be entered. The final window was designed to check diagnosis images, patient information, and diagnosis conditions. By learning how to enter patient information and change diagnosis conditions in this program, users will be able to understand more theories and terms learned in practice and thereby to shorten their learning time in actual clinical work.

• Wind and Structures
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• v.29 no.5
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• pp.339-359
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• 2019

Pre-stressed concrete poles are among the supporting systems used to support transmission lines. It is essential to protect transmission line systems from harsh environmental attacks such as downburst wind events. Typically, these poles are designed to resist synoptic wind loading as current codes do not address high wind events in the form of downbursts. In the current study, the behavior of guyed pre-stressed concrete Transmission lines is studied under downburst loads. To the best of the authors' knowledge, this study is the first investigation to assess the behaviour of guyed pre-stressed concrete poles under downburst events. Due to the localized nature of those events, identifying the critical locations and parameters leading to peak forces on the poles is a challenging task. To overcome this challenge, an in-house built numerical model is developed incorporating the following: (1) a three-dimensional downburst wind field previously developed and validated using computational fluid dynamics simulations; (2) a computationally efficient analytical technique previously developed and validated to predict the non-linear behaviour of the conductors including the effects of the pretension force, sagging, insulator's stiffness and the non-uniform distribution of wind loads, and (3) a non-linear finite element model utilized to simulate the structural behaviour of the guyed pre-stressed concrete pole considering material nonlinearity. A parametric study is conducted by varying the downbursts locations relative to the guyed pole while considering three different span values. The results of this parametric study are utilized to identify critical downburst configurations leading to peak straining actions on the pole and the guys. This is followed by comparing the obtained critical load cases to new load cases proposed to ASCE-74 loading committee. A non-linear failure analysis is then conducted for the three considered guyed pre-stressed concrete transmission line systems to determine the downburst jet velocity at which the pole systems fail.

• Journal of The Korean Association of Information Education
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• v.8 no.1
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• pp.101-110
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• 2004

The researcher designed and applied the cyber consultation system by making use of high-speed information networks and getting away from the established face-to-face consultation patterns in our society. The system is characterized by the means of communications to hold consultation with interviewees which enables us to feel free to converse with students in trouble and to more actively engage in interaction with the help of client-centered system. And it can also be used to help clients to change their attitudes towards consultation by relieving them of distrust, dislike and vague anxiety and to take active part in consultation. The established on-line consultation websites fail to continue consultation due to being able to hold secret consultation through e-mails. In this context, the researcher has produced the cyber consultation system to continuously hold various kinds of consultation including closed consultation between consultants and interviewees with the help of web servers where individual homepages are used.

• Convergence Security Journal
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• v.12 no.6
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• pp.19-24
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• 2012

As the representative of the convergence of broadcasting and communication, the data service was expected to be a new profit source of the related industries. The data service, however, has not satisfied the expectation due to the short of killer services that make it popular with the viewers. According to the several survey reports, a lot of viewers do internet-searching using the key-words related to the TV program they are watching and, with the faith in the survey results, several trials has been performed to port established PC-based searching systems onto TV-set only to fail to get popularity among viewers. The failures are mainly caused that they did not sufficiently consider the viewers' modality that viewers seriously want not to be obstructed by anything when they are absorbed in a program. This paper proposes an MHP-based searching data service designed to minimally interrupt the viewers watching a TV program and to be synchronized with a TV program by using the searching key-words relative to it, the content of which changes as time goes on.

• Journal of the Ergonomics Society of Korea
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• v.30 no.1
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• pp.19-28
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• 2011

Objective: The aim of this study is to reclassify human errors and to develop hands-on tools to apply the new classification for preventing human error accidents in highway construction site. Background: The main cause of accidents in highway construction was reported as the carelessness of workers. However, such diagnosis could not help us operationally prevent accidents in real workplace. Method: The accidents in highway construction were reanalyzed and the causes of human error were reclassified in order to educate and improve the awareness of human error in highway construction. Field survey and interview with safety managers and workers were conducted to find the causal relationship between the actual accidents and the human errors. Results: The most frequently observed human errors in highway construction were classified into six categories such as mis-perception, distraction, memory fail, slip, cognition error and mis-judgment. In order to provide hands-on tools to increase the awareness of human error in construction field, the human error checklist and card sorting diary were developed. Especially, the card sorting diary was designed to increase the ability in human error inspection of safety manager at construction site. Moreover, posters were developed based on actual accident cases. Conclusion: We suggested that the improved awareness and analytical report on checklist, card sorting diary and posters for construction field could collectively prevent the accident. Application: The classification of human error, hands-on tools and posters can be directly applicable on highway construction site. This analytical and collective approach preventing human error-related accident could be extended to other construction workplaces.