• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.18 no.12
• /
• pp.1884-1892
• /
• 1993

In push out scheme, high priority cell which arrives when the buffer is full pushs low priority cell. The PBS scheme provides priority by variable threshold in buffer.In this paper, for Controlling congestion in ATM network we propose buffer processing method in which the PBS scheme has variable threshold. And we analysis The performance of this scheme. As a result of simulation, the proposed push out scheme with variable threshold reduces the loss of low priority cell compared with existing push out scheme. This proposed method not only reduces the loss of high priority cell like existing push out scheme but also reduces the loss of low priority cell by variable threshold.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.46 no.3
• /
• pp.10-17
• /
• 2009

This paper proposes a compressed domain signature extraction method which can be used for CBCD (Content Based Copy Detection). Since existing signature extraction methods for the CBCD are executed in spatial domain, they need additional computations to decode the compressed video before the signature extraction. To avoid this overhead, we generate a thumbnail image directly from the compressed video without full decoding. Then we can extract the video signature from the thumbnail image. Experimental results of extracting brightness ordering information as the signature for CBCD show that our proposed method is 2.8 times faster than the spatial domain method while maintaining 80.98% accuracy.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.18 no.6
• /
• pp.871-880
• /
• 1993

Conventional binary addition rules require a carry formation and propagation to the most significant bit, and lead to serial addition. Thus, the carry progapation in a binary addition stands as a hindrance to the full utilization of parallelism optics offers, Optical adders using a modified signed-digit(MSD) number system have been proposed to eliminate the carry propagation chain states to represent the three possible digits of MSD number system must encode three different states to represent the three possible digits of MSD. In the paper, we propose the design of a parallel optical adder based on 2-bit addition rules using the method of symbolic substitution(SS).

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.21 no.1
• /
• pp.131-143
• /
• 1996

In this paper, we propose the improved structure of fully interconnected ATM Switch to develop the small sized switch element and represent practical implementation of switch network. As the part II of the full study about structure and implementation of fully interconnected ATM Switch, this paper especially describes the implementation of an ATM switching element with 8 input port and 8 output port at 155 Mbits/sec each. The single board switching element is used as a basic switching block in a small sized ATm switch for ATM LAN Hub and customer access node. This switch has dedicated bus in 12 bit width(8 bit data + 4 bit control signal) at each input and output port, bit addressing and cell filtering scheme. In this paper, we propose a practical switch architecture with fully interconnected buses to implement a small-sized switch and to provide multicast function withoutany difficulty. The design of switching element has become feasible using advanced CMOS technology and Embedded Gate Array technology. And, we also represent Application Specific Integrated Circuit(ASIC) of Switch Output Multiplexing Unit(SOMU) and 12 layered Printed Circuit Board for interconnection network of switch.

• Journal of KIISE:Information Networking
• /
• v.34 no.5
• /
• pp.396-404
• /
• 2007

In this paper, an Ad-hoc Routing Protocol which works in wireless Ad-hoc communication networks with multiple radios and multiple channels, and controls call admission based on bandwidth measurement is proposed. Unlike the conventional Ad-hoc node with a single radio using a single channel, an Ad-hoc node of the protocol proposed, MCQosR(Multiple Channel Quality of Service Routing), has multiple radios and uses multiple channels, which makes full duplex transmission between wireless Ad-hoc nodes, and reduces the intra interference on a route. Also, a fixed channel only for reception at each node enables the measurement of the available bandwidth, which is used to control the call admission for QoS provision. The performance of MCQosR is verified by simulation.

• Journal of the Korean BIBLIA Society for library and Information Science
• /
• v.26 no.4
• /
• pp.83-104
• /
• 2015

This study intends to provide guidance for library design and assessment by eliciting the emotional vocabulary related to academic library space. In order to accomplish the goal of this study, 12 major emotional vocabularies related to academic library space were derived through 5 stages of extraction and refinement processes. Literature search and analysis of preceding research, focus group interview and survey of academic librarians and users of the academic library, evaluation of similarity through KJ Method, etc., selected 12 adjectives of emotional vocabulary as follows: diverse, satisfactory, necessary, full, clean, stable, appropriate, harmonious, open, warm, natural, and excellent.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.17 no.10
• /
• pp.2461-2465
• /
• 2013

This paper investigates the influence of hydrogen loading process on the radiation sensitivity of fiber Bragg gratings (FBG). We made the FBG inscribed in the same commercial Ge-doped fiber with different hydrogen loading periods. We measured the Bragg wavelength shift (BWS) of the FBG exposed to gamma-radiation up to a dose of 18 kGy, and evaluated the change of full width at half maximum (FWHM) and the FBG temperature sensitivity coefficient after irradiation. Varying hydrogen loading parameter led to BWS differences up to nearly a factor of two.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.15 no.11
• /
• pp.2457-2464
• /
• 2011

In this paper, a vibration energy harvesting circuit using a piezoelectric device is designed. MPPT(Maximum Power Point Tracking) control function is implemented using the electric power-voltage characteristic of a piezoelectric device to deliver the maximum power to load. The designed MPPT control circuit traces the maximum power point by periodically sampling the open circuit voltage of a full-wave rectifier circuit connected to the piezoelectric device output and delivers the maximum available power to load. The proposed vibration energy harvesting circuit is designed with $0.18{\mu}m$ CMOS process. Simulation results show that the maximum power efficiency of the designed circuit is 91%, and the chip area except pads is $700{\mu}m{\times}730{\mu}m$.

• Journal of the Korean Society for Library and Information Science
• /
• v.46 no.1
• /
• pp.55-76
• /
• 2012

Regardless of which country, all public libraries need facilities, collections, and funds. But how well the library system succeeds depends on the staff committed to providing the highest possible level of service to the community. The public library, therefore, should employ the appropriate number of full-time staff. In order to warrant such a work force, this study analyzed the juridical justification, logical validity, realistic fitness, and usefulness of current legal and recommended staffing standards. This study also suggested the revisions of total space of buildings and collection size as crucial variables for library staffing, division of legal service populations, basic staffing level, and additional staff in proportion to service populations for public libraries in Korea.

• Journal of the Korean Data and Information Science Society
• /
• v.25 no.1
• /
• pp.211-218
• /
• 2014

Qu et. al. (2000) proposed the quadratic inference functions (QIF) method to marginal model analysis of longitudinal data to improve the generalized estimating equations (GEE). It yields a substantial improvement in efficiency for the estimators of regression parameters when the working correlation is misspecified. But for the longitudinal data with time-dependent covariates, when the implicit full covariates conditional mean (FCCM) assumption is violated, the QIF can not provide more consistent and efficient estimator than GEE (Cho and Dashnyam, 2013). Lai and Small (2007) divided time-dependent covariates into three types and proposed generalized method of moment (GMM) for longitudinal data with time-dependent covariates. They showed that their GMM type II and GMM moment selection methods can be more ecient than GEE with independence working correlation (GEE-ind) in the case of type II time-dependent covariates. We develop upgraded QIF method for type II time-dependent covariates. We show that this upgraded QIF method can provide substantial gains in efficiency over QIF and GEE-ind in the case of type II time-dependent covariates.