• Journal of Korea Game Society
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• v.9 no.6
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• pp.79-92
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• 2009

Domestic on-line game market is growing quickly, but game company doesn't grasp trial of users, and it is bent on to the contents service supply that it was lumped together only. If cannot reflect mind of a user to game contents service, decrease of the existing customer and influx of a new customer is difficult as a loyalty duty of company is decreasingly market share drops, and this is large to company sales will beat it. I will present marketing strategy regarding game contents service of game companys in this study as detecting factors to affect to reuse intention of on-line game users.

• Journal of the Korea Society of Computer and Information
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• v.20 no.7
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• pp.57-64
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• 2015

In this paper, we propose a design of microwave motion detector using X-band doppler radar sensor to minimize the power consumption. To minimize the power consumption and implement battery operated system, pulse input with 2 KHz, 4% duty cycle is exerted on the doppler radar sensor. In order to simplify the process of working with ATmega2560 microcontroller unit, Arduino compatible board is designed and implemented. Arduino is open source hardware and many library software is published as open source tools. Smartphone app is also proposed and designed as a real-time user interface of the motion detector. The SQLite database on the Android mobile operating system is used for recording raw data of motion detection for post-processing job, such as fast Fourier transform (FFT). Bluetooth interface module is implemented on the motion detection board as a wireless communication interface to the smartphone. The speed of human movement is identified by post-processing FFT.

• Journal of the military operations research society of Korea
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• v.16 no.2
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• pp.118-134
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• 1990

This paper considers the mutual interference problem of several users employing the same FH systems in selected multiple user environments. The environment consists of a desired transmitter-receiver pair located in an area where there are M interfering users distributed in accordance with a specified probability density function. Both coherent Phase-Shift-Keyed and incoherent Frequencey-Shift-Keyed modulations are considered. The general formulas of the average bit error probability are derived. The calculation results are summarized and analyzed. The average bit error probability is highly dependent on the relative location of interferences to the desired link, the time duty factor of the hopping and the number of available channels.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.11
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• pp.1596-1602
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• 2021

Battery-operated IoT devices in IoT systems require low power consumption. In general, IoT devices enter a sleep state synchronously to reduce power consumption. A problem arises when an IoT device has to handle asynchronous user requests, as the duty cycle must be reduced to enhance response time. In this paper, we propose a new low-power-consumption scheme, called Repetitive Wake-up scheme for IoT systems of asynchronous environments such as indoor lights control. The proposed scheme can reduce power consumption by sending wake-up signals from the smartphone repetitively and by retaining the IoT device in sleep state to the smallest possible duty cycle. In the various environments with IoT devices at home or office space, we showed that the proposed scheme can reduce power consumption by up to five times compared to the existing synchronous interlocking technique.

• Journal of Korean Academy of Nursing Administration
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• v.5 no.2
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• pp.237-251
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• 1999

The purpose of this study is to suggest successful strategies through which the effect of the information system of a hospital can be forecasted at the nursing department. In order to set up successful strategies, in the first place, both the methods of CSF(Critical Success Factor: Rockart, 1979) and ULD(User-Led Development) method and the method suggested by the Korea Productivity Center were applied. In order to measure the improvement of nursing productivity, the Dissonance theory was used. The data were collected from 100 employees serving at the clinic department of Kwangju Patriots' and Veterans' Hospital from July 4 to July 25, 1998 with reference to all 222 cases, for sampling work; then the part of the efficiency of the treatment or management of hospital business - simplification of the process of the treatment of hospital business and reduction of the time of the treatment of hospital business were measured; and in order to forecast organizational behavior, 100 cases of organization behavior were analysed, based on the well structured, questionnaires. In order to forecast the user's organizational behavior, a tool(Ronald. 1988; Stephen, 1982: Senn, 1992: Olsen, 1980: Anderson, 1988: Kim. 1992: Cho. 1994) to measure the extent or degree of the user's recognition or understanding whose reliability coefficient is 0.63 was used: and regarding the items expected by the users concerning the convenience of the system, a tool created by Bernadett, Szajna and Richard W. Scamell(1993) whose reliability coefficient is 0.88 was used. And finally, those data were analysed, utilizing the statistical package of SPSS/PC 6.0. successful strategies are suggested as follows: 1. In order that the Kwangju Patriots' and Veterans' Hospital's purpose can be successful through its strategic, information system, the quality of its services should be elevated. and for elevating the quality of medical services, elevation of the quality of medical expertism or specialty is an important factor in determining such quality. 2. In order to make the hospital information system to be successful, the hospital's top manager should participate in the effort making it successful with helping hands of the members or personnel of the hospital. 3. In order to make users participate in the hospital information system, it is prerequisite that all nurses in a hospital should voluntarily participate in the system 4. In order to reduce the expense, the time in coping with business per duty should be reduced by 10${\sim}$33.23%. The time of the direct nursing care which added value is relatively high should be elongated in order to elevate the quality of hospital services. 5. Since the introduction and spread of the hospital information system are influenced by the duration in the experience of computer use, the user of the hospital information system should have a plan to receive well-planned computer education. Finally it is suggested that the forecast of long-term productivity through a review of the user's expectation of the system should be inspected and tested through continuous studies of its effectiveness.

• Journal of Digital Contents Society
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• v.15 no.2
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• pp.301-308
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• 2014

The mass storage of data and the importance of storage capacity lately has emerged. In this paper, we suggest the new method which estimate life cycle from acceleration life test about 2.5 inch hard disk driver as mass storage, which minimize the difference between real market annual failure rate and estimated failure rate. we obtain market transfer capacity per hours from returned 2.5inch hard disk drives about 309 numbers and accelerating transfer capacity per hours from acceleration life test. we calculate acceleration factor about duty cycle and estimate annual failure rate from failure rate and acceleration factors: temperature acceleration factor, duty cycle acceleration factor, the transfer capacity per hour represent the 93.4 % of user is 5.8 GB/hour, the transfer capacity per hour from acceleration life test is 81.4 GB/hour. the acceleration factor of duty cycle is 14.1. annual failure rate is stabilized at market one year after, annual failure rate is between 0.3 and 0.378. estimated annual failure rate is 0.4, so it is matched at 75~94 % between estimate annual failure rate and market annual failure rate. This study influence the estimate method of annual failure rate by the result of acceleration life cycle of manufacture.

• Journal of Internet Computing and Services
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• v.7 no.1
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• pp.17-30
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• 2006

With the wide acceptance of the Internet and the Web, volumes of information and related users have increased and companies have become to need security mechanisms to effectively protect important information for business activities and security problems have become increasingly difficult. This paper proposes a improved access control model for access control enforcement in enterprise environments through the integration of the temporal constraint character of the GT-RBAC model. sub-role hierarchies concept and PBDM(Permission Based Delegation Model). The proposed model. called Extended GT-RBAC(Extended Generalized Temporal Role Based Access Control) delegation Model. supports characteristics of GTRBAC model such as of temporal constraint, various time-constrained cardinality, control flow dependency and separation of duty constraints (SoDs). Also it supports conditional inheritance based on the degree of inheritance and business characteristics by using sub-roles hierarchies and supports permission based delegation, user to user delegation, role to role delegation, multi-step delegation and temporal delegation by using PBDM.

• Journal of the Institute of Convergence Signal Processing
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• v.10 no.3
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• pp.193-197
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• 2009

In this paper, we study on design of vehicle control system which is based on ${\mu}C/OS-II$, We component a electric motor drive system for simulator because the most of vehicle part use electric motor for actuator. We use the XC2287 microcontroller which is often used vehicle body controller because XC2287 guarantee high confidence and durability in vehicle industry. The electric motor control system derive PWM from general I/O port in XC2287 microcontroller. The signal is supplied at electric motor after amplifying that using driver circuit. The user control duty of PWM signal through controlling potentiometer which is connected to XC2287. through that, the user control speed of electric motor. we synchronize both input process via controlling potentiometer and PWM output process using semaphore. we verify porting of ${\mu}C/OS-II$ via experimentation.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.6
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• pp.266-283
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• 2022

With the rapid development of autonomous vehicle technology, unexpected accidents are occurring. Therefore, it is necessary to minimize user accident damage through the development of autonomous traffic safety education. Since edge cases, accident type, and risk factor analysis are important for realistic education, overseas case studies and demonstrations were carried out, and based on this, two curriculum for service providers and general users were developed. The service provider curriculum consisted of OEDR, sudden stop, cut-in, take-over, defensive driving, system malfunction, policy and information security education, and the general user curriculum consisted of attention duty, take-over, operating design domain, accidents type, laws, functions, information security education.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.851-860
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• 2020

With an increase in the aging population and a rising social interest in health and welfare, studies to improve healthcare in the elderly are being actively conducted. This study attempted to improve the current design and manufacture of elevating electric wheelchairs to enhance user safety and convenience. Seat design based on the user's body shape, convenience while boarding or alighting, caster turning radius and, safety and stability features that prevent shaking when the user gets up or sits down were improved. A driving experiment was conducted to evaluate the operation of the indoor electric wheelchair designed and manufactured with these additional functionalities. During the test, the performance parameters evaluated were continuous driving time, turning radius, maximum lifting and lowering load, maximum lifting height, noise level, minimum distance sensing by the driving auxiliary sensor, ability to interact with server and app programs, and the duty cycle maximum error rate. The test confirmed that this improved electric wheelchair successfully met target parameters. In a future study, we will evaluate this improved electric wheelchair from a user's perspective for its usability parameters, such as satisfaction, convenience and stability.