• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.35 no.8C
• /
• pp.651-660
• /
• 2010

In this paper, we implement an efficient histogram-based prefiltering to compensate the illumination mismatches in regions between neighboring views. In multi-view video, such illumination disharmony can primarily occur on account of different camera location and orientation and an imperfect camera calibration. This discrepancy can cause the performance decrease of multi-view video coding(MVC) algorithm. A histogram matching algorithm can be exploited to make up for these differences in a prefiltering step. Once all camera frames of a multi-view sequence are adjusted to a predefined reference through the histogram matching, the coding efficiency of MVC is improved. However general frames of multi-view video sequence are composed of several regions with different color composition and their histogram distribution which are mutually independent of each other. In addition, the location and depth of these objects from sequeuces captured from different cameras can be different with different frames. Thus we propose a new algorithm which classify a image into several subpartitions by its depth information first and then histogram matching is performed for each region individually. Experimental results show that the compression ratio for the proposed algorithm is improved comparing with the conventional image-based algorithms.

• The Journal of Information Systems
• /
• v.25 no.4
• /
• pp.141-161
• /
• 2016

Purpose As crowdfunding is a relatively recent phenomenon, determinants of successful crowdfunding with empirical data have been under-researched. Consequently, we examine the role of information- and behavior-based social interaction on the performance of crowdfunding projects, while investigating the motivational factor of goal achievement. Design/methodology/approach From February to August 2016, we collected panel data on 154 crowdfunding projects, which completed fundraising successfully on Tumblbug, a reward-based crowdfunding platform in Korea. In this study, we examine the roles of information-based social interaction (e.g., sharing information on a crowdfunding project) and behavior-based social interaction (e.g., following other investors' behavior) on successful crowdfunding. Additionally, we investigate whether the motivation of goal achievement moderates the relationship between social interaction and performance of crowdfunding projects or not. Findings We find that the number of times a crowdfunding project is shared has a positive influence on its performance, as does the number of project backers. Furthermore, we confirm that goal achievement motivation moderates the effects of information- and behavior-based social interaction on the performance of crowdfunding projects.

• 한국정보교육학회:학술대회논문집
• /
• 2007.08a
• /
• pp.59-64
• /
• 2007

본 연구에서는 사이버가정학습을 교사가 교실 수업과 사이버가정학습 시스템을 연계하여 운영함에 있어 어떤 요인이 사이버가정학습에 대한 학습자 만족에 영향을 미치는지를 분석하였다. 기술수용모형을 기반으로 Y초등학교 5학년 학생들을 대상으로 6개월간 운영한 후 설문조사를 실시하였다. 분석결과 초등학생들에게 사이버가정학습 만족도는 지각된 유용성과 용이성에 의하여 결정되는 것으로 나타났으며, 자기주도적 학습 능력과 학습결과보상기능은 사이버가정학습을 긍정적으로 수용할 수 있는 유용성에 상당한 영향을 미치는 중요한 요인으로 작용하는 것으로 분석되었다. 만족도에 영향을 미칠 것으로 예상했던 교육적 효과, 콘텐츠 품질은 만족도를 직접적으로 유발시키는 본질적인 요인이 아님을 알 수 있었다. 학습지원기능, 시스템 안정성 및 편리성, 상호작용 등 시스템적인 기능이 만족도에 유의미한 영향을 미치지 못하는 것으로 나타났다. 이 요인들은 단지 콘텐츠의 품질을 향상시키는 효과를 가지며, 이 효과를 통해 교육적 효과를 강화시키는 역할을 수행하는 것으로 분석되었다. 따라서 학습을 지원하는 기능, 시스템 안정성 및 편리성, 선생님과 학생 또는 학생 간의 상호작용이 가능하도록 지원하는 모든 시스템적인 기능은 수강생의 만족도에 직접적인 영향을 미치거나 만족을 이끌어 낼 수 있는 본질적이고 핵심적인 요인이 아님을 알 수 있다.

• Transactions of the KSME C: Technology and Education
• /
• v.1 no.2
• /
• pp.153-165
• /
• 2013

The established gait analysis studies have regarded leg as one single spring. If we can design a knee-ankle actuating mechanism as a primary actuator for supporting knee extension, it might be possible to revolutionary store or release elastic strain energy, which is consumed during the gait cycle, and as a result leg stiffness is expected to increase. An ankle joint actuating mechanism that stores and releases the energy in ankle joint is expected to support and solve excessive artificial leg stiffness caused by the knee actuator (primary actuator) to a reasonable extent. If unnecessary kinematic energy is released with the artificial speed reduction control designed to prevent increase in gait speed caused by increase in time passed, it naturally brings question to the effectiveness of the actuator. As opposed to the already established studies, the authors are currently developing knee-ankle two actuator system under the concept of increasing lower limb stiffness by controlling the speed of gait in relative angular velocity of the two segments. Therefore, the author is convinced that compensatory mechanism caused by knee actuating must exist only in ankle joint. Ankle joint compensatory mechanism can be solved by reverse-examining the change in metatarso-phalangeal joint (MTPJ) tilt angle (${\theta}_1=0^{\circ}$, ${\theta}_2=17^{\circ}$, ${\theta}_3=30^{\circ}$) and the effect of change in gait speed on knee activity.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.37 no.5
• /
• pp.23-30
• /
• 2000

To compensate the nonlinearity of electroabsorption modulator(EAM) resulting from its near exponential transfer function, a semiconductor optical amplifier(SOA) that has a log transfer function is used. Since the transfer function of SOA is inverse to that of EAM, the intermodulation distortion(IMD) of EAM can be reduced by cascading SOA to EAM. Also, the RF gain can be increased by the optical gain of SOA. For these reasons, spurious free dynamic range(SFDR) of EAM is enhanced by connecting SOA to EAM in series and operating in gain salutation region. To improve the nonlinearity compensation of EAM, the increased gain of SOA is required and the slope of gain saturation, the ratio of gain to input SOA power, needs to be steep. However, signal spontaneous beat noise that is the dominant system noise increases in proportion to the gain such that the SFDR of EAM is reduced. The higher the gain of SOA is, the more ASE is increased. Thus the noise level of system is increased and the following SFDR of EAM is decreased. The slope of gain saturation region and ASE of have trade-off relation and the optimization is achieved at 8㏈ optical gain. 9㏈ enhancement of SFDR of EAM is obtained. This scheme is easy to embody the linear EAM and the integration with three components (DFB-LD, EAM and SOA) offers many merits, such as low insertion loss, low chirping and low polarization sensitivity.

• Journal of the Korean Society for information Management
• /
• v.41 no.1
• /
• pp.509-536
• /
• 2024

The purpose of this study is to develop a metadata AP for managing the person and organization name authority data in the National Debt Redemption Movement Digital Archive, a small-scale digital archive. The design principles and core metadata elements were derived by analyzing person/organization(group or corporateBody) metadata standards, implementation practices, and guidelines of libraries and archives, and mapped to the National Debt Redemption Movement person/organization name thesaurus data and the Wikidata Linked Metadata Model, resulting in 10 elements in the identification area, 14 elements in the content area, 8 elements in the relationship area, and 4 elements in the control area. A simple structure schema was applied so that it can be applied even in small organizations, and for interoperability, the schema was proposed with reference to DublinCore and SKOS schemes, and the applicability was confirmed based on actual data. The results of this study can be utilized as a basis for institutions that recognize the importance of data management but have difficulty in applying it in practice, when they want to prepare a system for managing their own authority data.

• Informatization Policy
• /
• v.22 no.4
• /
• pp.91-104
• /
• 2015

This study tests the effects of differential association, definitions, differential reinforcement and imitation from social learning theory in the explanation of university students' crimes in social network services. In addition, this study tests the interaction effects between social learning factors and other factors such as low self-control, subcultural environment, and crime opportunity for the integrated approach. Using data from 486 university students in Seoul, results show that both definition and imitation have significant influences on crimes, even though differential association and differential reinforcement factors have no significant influences on crimes in social network services. Results also reveal that there are significant interaction effects between definition and subcultural environment, which meana that definition has a strong effect on crimes in high subcultural environment. In addition, it is found that reinforcement has also a strong effect on crimes in high crime opportunity and that interaction effect between imitation and low self-control is significant, which means that imitation has a strong effect on crimes in low self-control students.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.45 no.5
• /
• pp.33-39
• /
• 2008

We have experimentally demonstrated the transmission performance of a feedforward optical transmitter using an external light injection technique. The feedforward compensation method shows 31 dB intermodulation distortion suppression and 2.2 dB noise reduction. A high side-mode suppression ratio exceeding 35 dB of the wavelength of the locked Fabry-Perot laser diode was obtained over 12 nm ranges. The suppression characteristics of the intermodulation distortion for various wavelength differences and transmission lengths were measured and analyzed as the evaluation criteria for the system performance in WDM/SCM based radio-over-fiber systems.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.34 no.9C
• /
• pp.896-905
• /
• 2009

In this paper, we propose an enhanced iterative ICI (Inter Carrier Interference) cancellation method for cooperative STBC-OFDM (Space Time Block Coded-Orthogonal Frequency Division Multiplexing) system. In cooperative STBC-OFDM system, ICI cancellation is necessary because ICI due to the independent local oscillators always exits. The conventional iterative ICI cancellation method has severe performance degradation due to the initial estimation error. Also the performance degradation increases as CFOs (Carrier Frequency Offsets) and modulation order increases. Therefore, in this paper, we propose an enhanced iterative ICI cancellation method which can reduce the initial estimation error by giving a priority to initial estimation and cancellation process. Through the complexity and performance comparisons, we verwey that the proposed method has better performance with approximately same complexity compared with the conventional method.

• Journal of the Korea Society for Simulation
• /
• v.22 no.1
• /
• pp.53-61
• /
• 2013

The purpose of this paper is to examine how the humans learn and perceive the weight of objects corresponding to visual information in virtual environment. We conducted two kinds of load-on-tasks with two virtual objects that have same weight but different visual cues; have same visual cues but changed weight by trails. We found that the subject could not generate appropriate force for the smaller and changed weight objects in the beginning of the trials. the discrepancy between the expected weight and actual force consequences sue to visually invoked size and previous experience made subjects perceive the small object were heavier. one the other hand, after the tasks were repeated, the subject responded the weights were the same or very similar when the mismatch between the expected weight and the actual weight became vanished. this means that the sensorimotor feedback influences the anticipatory control scheme and weight perception aggressively in virtual environment.