• ETRI Journal
• /
• v.32 no.2
• /
• pp.222-229
• /
• 2010

A conventional pseudorandom sequence generator creates only 1 bit of data per clock cycle. Therefore, it may cause a delay in data communications. In this paper, we propose an efficient implementation method for a pseudorandom sequence generator with parallel outputs. By virtue of the simple matrix multiplications, we derive a well-organized recursive formula and realize a pseudorandom sequence generator with multiple outputs. Experimental results show that, although the total area of the proposed scheme is 3% to 13% larger than that of the existing scheme, our parallel architecture improves the throughput by 2, 4, and 6 times compared with the existing scheme based on a single output. In addition, we apply our approach to a $2{\times}2$ multiple input/multiple output (MIMO) detector targeting the 3rd Generation Partnership Project Long Term Evolution (3GPP LTE) system. Therefore, the throughput of the MIMO detector is significantly enhanced by parallel processing of data communications.

• Proceedings of the IEEK Conference
• /
• 2004.08c
• /
• pp.681-685
• /
• 2004

Design of efficient Medium Access Control (MAC) protocols with both high throughput performances is a major focus in distributed contention-based MAC protocol research. In this paper, we propose an efficient contention-based MAC protocol for wireless Local Area Networks, namely, the Developed Collision Resolution (DCR) algorithm. This algorithm is developed based on the following innovative ideas: to speed up the collision resolution, we actively redistribute the backoff timers for all active nodes; to reduce the average number of idle slots, we use smaller contention window sizes for nodes with successful packet transmissions and reduce the backoff timers exponentially fast when a fixed number of consecutive idle slots are detected. We show that the proposed DCR algorithm provides high throughput performance and low latency in wireless LANs.

• Journal of information and communication convergence engineering
• /
• v.12 no.4
• /
• pp.199-207
• /
• 2014

A new cooperative MAC protocol called the busy tone cooperative medium access control (BT-COMAC) protocol is proposed to overcome the drawbacks and maximize the advantages of existing schemes. This scheme uses a new metric called decibel power to decide an appropriate helper node. Using received power strength is more efficient in selecting an appropriate helper node, especially in a densely populated network, than the effective transmission rates used in conventional schemes. All communication nodes in a communication service area are assumed to move independently. Two performance metrics are used: System throughput and channel access delay. A performance evaluation of the BT-COMAC protocol is conducted using a computer simulation over a slow fading wireless channel, and its performance results are compared with those of four existing schemes. The numerical results show that the BT-COMAC protocol improves the system throughput by approximately 15% as compared to the best existing scheme.

• Journal of Navigation and Port Research
• /
• v.39 no.5
• /
• pp.417-422
• /
• 2015

Sea-ports in Northern Vietnam have experienced a rapid growth of container throughput in recent years. To accompany with such development, huge investment also has been performed to enhance not only local port capacity but also the regional logistics system. Container terminals in Northern Vietnam locate centrally along Cam river of Haiphong city, leaving 2 others in Quang Ninh province. Five out of totally 11 container terminals in the area are under the control of Vinalines - a national corporation in field of maritime industry. In this paper, those terminals are classified in terms of location and ownership. The volume of container throughput and facilities of all container terminals in Northern Vietnam from 2005 to 2014 are recorded in order to compare the performance of groups. A Data Envelopment Analysis (DEA) is then applied to evaluate the relative efficiency of such terminals. Before conclusion, number of suggestions will be contributed to related parties.

• BMB Reports
• /
• v.37 no.1
• /
• pp.28-34
• /
• 2004

The discovery of biochemical and cellular functions of unannotated gene products begins with a database search of proteins with structure/sequence homologues based on known genes. Very recently, a number of frontier groups in structural biology proposed a new paradigm to predict biological functions of an unknown protein on the basis of its three-dimensional structure on a genomic scale. Structural proteomics (genomics), a research area for structure-based functional discovery, aims to complete the protein-folding universe of all gene products in a cell. It would lead us to a complete understanding of a living organism from protein structure. Two major complementary experimental techniques, X-ray crystallography and NMR spectroscopy, combined with recently developed high throughput methods have played a central role in structural proteomics research; however, an integration of these methodologies together with comparative modeling and electron microscopy would speed up the goal for completing a full dictionary of protein folding space in the near future.

• Toxicological Research
• /
• v.25 no.2
• /
• pp.59-69
• /
• 2009

Metabolomics which deals with the biological metabolite profile produced in the body and its relation to disease state is a relatively recent research area for drug discovery and biological sciences including toxicology and pharmacology. Metabolomics, based on analytical method and multivariate analysis, has been considered a promising technology because of its advantage over other toxicogenomic and toxicoproteomic approaches. The application of metabolomics includes the development of biomarkers associated with the pathogenesis of various diseases, alternative toxicity tests, high-throughput screening (HTS), and risk assessment, allowing the simultaneous acquisition of multiple biochemical parameters in biological samples. The metabolic profile of urine, in particular, often shows changes in response to exposure to xenobiotics or disease-induced stress, because of the biological system's attempt to maintain homeostasis. In this review, we focus on the most recent advances and applications of metabolomics in toxicological research.

• Journal of information and communication convergence engineering
• /
• v.6 no.2
• /
• pp.228-232
• /
• 2008

In recent years, wireless ad hoc networks have become increasingly popular in both military and civilian applications due to their capability of building networks without the need for a pre-existing infrastructure. Recently, IEEE 802.11 Task Group e has been working on a new mechanism, the Enhanced Distributed Coordination Function (EDCF), to enhance the performance of 802.11 DCF. However, EDCF only reduces the internal collisions within a station, and external collisions between stations remain high in ad-hoc networks. In this paper, we propose to adopt an adaptive backoff window control technique, based on a dynamic value of the initial value of the range in which the backoff is chosen, so the backoff timer is randomly chosen in the range (InitRng, CW-1). We use ns-2 simulation to evaluate the throughput of our scheme. Results show that the throughput is improved for our scheme compared to the original DCF due to the reduced the number of collisions.

• Journal of information and communication convergence engineering
• /
• v.6 no.2
• /
• pp.158-163
• /
• 2008

The MB-OFDM based UWB communication system is a personal area network specification aiming to provide 480Mbps peak data rate over 528 MHz spectrum. As the corresponding baseband modem operates at high clock rate, its complexity should be optimized for low power consumption. A set of modem design parameters is suggested including the AD bit width, the clipping level and the quantization level at the Viterbi decoder input as well as the trace-back depth of the Viterbi decoder. The data throughput is used to evaluate the performance of the receiver and a recommended set of design parameter values is presented to aid efficient modem implementation.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.21 no.4
• /
• pp.893-910
• /
• 1996

Recently, there ary many researches on local area multichannel network as WDM technology developes. An ideal media access protocol in a multichannel network is one that shows short access delay under low load and high throughput under heavy load. This paper proposed a new media access protocol for WDM passive star coupler network. The proposed one is a random access rpotocol based on reservation. Access delay is short under low load by using random access method, and high throughput is achieved under heavy load by usin greservation access. Analytic model for the performance analysis of the proposed protocol is developed and performance of the proposed protocol is compared with the previous ones. The effect on the performance of the number of the nodes and channels, and the number of transceivers in each node are analyzed.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.8 no.6
• /
• pp.1901-1913
• /
• 2014

The IEEE 802.15.6 is a communication standard for Wireless Body Area Networks (WBANs). This standard includes a prioritized slotted Aloha as a choice for medium access control. This protocol is different from the traditional version as it has integral considerations for certain priorities of users. It attempts to resolve collision by halving the probability of retransmission, lower bounded by to a minimum, in the alternate slots to follow. In this paper, we present an analytical model to compute the non-saturated throughput of this protocol in the presence of finite number of nodes. The model is validated against simulation.