• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.12 no.5
• /
• pp.11-16
• /
• 2012

Opportunistic transmit cooperative relaying (OTR) system has been interested for its ability to mitigate the fading in wireless channel without multiple antennas in a small terminal. In OTR system, only the relays that the received Signal-to-noise ratio (SNR) from a source is greater than the threshold transmit to the destination. However, the receiving branches of a destination in a realistic system is fixed, the excess number of signals from the transmit relays does not improve the system performance and consequently increases power consumption. In this paper, we adopt Double Opportunistic Transmit (DOT) cooperative diversity system which controls the average number of transmit relays. Although the average number of the transmit relays can be controlled by adjusting the two thresholds in DOT system, the instantaneous number of transmit relays is varying in fading channel. Thus we propose Maximal Ratio Combining (MRC) or Generalized Selection Combining (GSC) according to the number of the signals from relays at the destination. The outage probability of the proposed system is derived in closed form. The analytical results show that the system performance is improved with the number of the branches. Also it is noticed that when the number of the branches is fixed, the outage probability decreases with the increase of the average SNR of S-R path and R-D path.

• Applied Microscopy
• /
• v.17 no.1
• /
• pp.131-160
• /
• 1987

Anatomical features of the renal papilla and pelvis and ultrastructures of the epithelium covering these areas in four species of mammals were studied by means of light, scanning and transmission electron microscopy. In terms of the morphology of mammalian kidney types distinguished by Sperber(1944), Pfeiffer(1968) and Schmidt-Nielsen(1977), the kidneys of animal species used in this experiment were; 1) the mouse kidney with the fornix between a long conical papilla and the funnel-shaped pelvis, 2) the guinea pig kidney with the peripelvic column and pelvic pouch between a short conical papilla and the funnel-shaped pelvis, 3) the dog kidney with the peripelvic column and pelvic pouch between the crest-shaped papilla and the funnel-shaped pelvis, and 4) the cattle kidney which is divided into multiple renculi with minor and major calyces and pelvis. The renal papilla was lined with the simple or pseudostratified columnar epithelium which covered the inner zone of the renal medulla. The epithelial cells with numerous short microvilli on the surface contained a few organelles. In the mouse, the fornix was lined with one to two cell-layered cuboidal epithelium which covered the outer zone of the renal medulla and a part of the cortex. The epithelial cells of the fornix with numerous short microvilli or microridges on the surface had well-developed organelles. In the guinea pig, the peripelvic column was lined with the simple cuboidal or low columnar epithelium which covered the outer zone of the renal medulla. The epithelial cells with numerous short microvilli on the surface contained well-developed organelles. The pelvic pouch was lined with the pseudostratified columnar epithelium which was composed of four kinds of cells; the secretory cell with small electron-dense granules (310 nm), the secretory cell with large granules (720 nm) showing various electron densities, the mitochondria-rich cell with a single cilium, and the basal cell. Pelves of the mouse and guinea pig, peripelvic column, pelvic pouch and pelvis of the dog, and minor and major calyces and pelvis of the cattle were lined with the transitional epithelium. The fusiform vesicles in the superficial cells of the epithelium were highly developed in the dog, relatively well developed in the mouse and guinea pig, and poorly developed in the cattle. From the above findings, it is suggested that the transport of solutes and water of the urine in the pelvic cavity can take place through the epithelia covering the renal papilla and fornix of the mouse, papilla and peripelvic column of the guinea pig, and papillae of the dog and the cattle. And specialized cell types in the epithelium of the guinea pig pelvic pouch, two kinds of secretory cells and mitochondria-rich cell with a single cilium, could have peculiar functions in the renal pelvis, respectively.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.52 no.8
• /
• pp.74-85
• /
• 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 Acoustical Society of Korea
• /
• v.20 no.5
• /
• pp.69-75
• /
• 2001

In this paper, a fast and easy impedance matching method, which could give the impedance matching component for the general 1 or 2-port network was introduced. First, the entire network structure was defined which consists of the network part to be matched and the impedance matching part composed of inductors and capacitors. Next, the transmission matrix and input and output impedances of the entire network from the terminal impedance conditions were calculated, then the exact solutions for the matching components were obtained. To verify the efficiency of this method, this method was applied to the CDMA If band withdrawal weighted SAW transversal filter, and investigated the effects of the impedance matching before and after, through the simulation and experiment. As the result, the performance of a fractional bandwidth of 1.2%, insertion loss of 29 dB, and VSWR of 80 have improved to a factional bandwidth of 1.8％, insertion loss of 9 dB, VSWR of 3 at 85.38 MHz center frequency. The result shows that this impedance matching method could be used in the SAW devices and other types of 1 or 2-port network.

• Journal of Korean Ophthalmic Optics Society
• /
• v.7 no.1
• /
• pp.9-13
• /
• 2002

It is well known that the maximum amplitude of accommodation decreases with increasing age.(Presbyopia). With single vision lenses presbyopia can be corrected only for one viewing distance. With progressive power lenses presbyopia can be corrected for all viewing distances. But there are some other changes in the visual system with age which can not be corrected by spectacle lenses. Pupillary diameter decreases and the light transmission of the ocular media decreases. Therefore old people need more light, they need better illumination. Cone density in the retina decreases, this is only one example for changes in the sensory system. These changes in the visual system cause changes in visual functions. At the age of 80 visual acuity has decreased to half. Contrast sensitivity for gratings decreases mainly for high spatial frequencies very important is the increase of stray light in the ocular media and therefore the increase of glare. Veiling luminance increases by a multiple of approximately 4, Dark adaptation gets slower and light sensitivity is approximately 2 log units (factor 100) less when the eye is completely dark adapted. Also colour vision gets worse, especially at low luminances. Elderly people have problems with visual tasks which require divided attention between foveal and peripheral vision. An example is the measurement of the useful field of view. This useful field of view be expanded (improved) by visual training.

• Microbiology and Biotechnology Letters
• /
• v.41 no.1
• /
• pp.96-104
• /
• 2013

Staphylococcus aureus is a major human pathogen that produces a wide array of toxins, leading to a number of adverse symptoms. We examined 275 strains of Staphylococcus aureus isolated from various foods between 2006 and 2008 for antimicrobial susceptibility. At least 259 (94.2%) of the tested strains showed antibiotic resistant properties, and 106 (40.7%) of them showed multiple antibiotic resistance. Eleven of the tested strains were resistant to oxacillin and mec A-positive. Moreover, oxacillin-resistant strains were significantly more likely to be multi-drug resistant (p < 0.01). Of the 275 isolates tested, 24.4% were noted as being positive for slime production and 30.5% were positive for biofilm assay. Antibiotic resistance was not associated with a significantly higher prevalence of biofilm formation. Twenty strains were classified using the DiversiLab system. Most of the strains could be classified into 2 clusters and 4 unique types. All 10 mec A-positive strains (cluster I) were grouped together into the same sub-cluster. Cluster II (6 strains) was not found to be resistant to oxacillin in this study. Although the prevalence of methicillin-resistant S. aureus in food is currently low, the risk of its transmission through the food chain cannot be disregarded.

• The Journal of Korean Society of Virology
• /
• v.29 no.2
• /
• pp.119-127
• /
• 1999

Phylogenetic analysis was conducted to monitor transmission of HIV and to investigate the genetic structure of primary isolates from 12 HIV-1 subtype A infected Koreans. The individuals infected with subtype A viruses had been diagnosed as HIV-1 seropositives during the period 1987 to 1995 and blood samples have been collected from 1991 to 1997. DNA of each individual was isolated from uncultured or cultured peripheral blood mononuclear cells. V3-V5 (0.7 kb) fragment of HIV-1 env gene was amplified by nested polymerase chain reaction and the PCR products were sequenced. The mean value of the divergence of nucleotide of HIV-1 env V3-V5 fragment was $17.0{\pm}4.06%$ ($8.6{\sim}25.8%$) within HIV-1 subtype A isolates from Koreans. This diversity was higher than those of African isolates ($13.7{\pm}2.66%$). In the phylogenetic tree, Korean subtype A isolates were not grouped together, but intermingled into African isolates. The results of this study suggested that HIV-1 subtype A variants be introduced from multiple sites of Africa into Korea and the big genetic diversity of Korea HIV-1 subtype A isolates may be further influenced by the range of geographic locations in which the infection occurred rather than the elapsed time between infection and collection of samples and the disease progression.

• Journal of Broadcast Engineering
• /
• v.15 no.2
• /
• pp.205-216
• /
• 2010

In this paper, a method of MPEG-2 Transport Stream (TS) multiplexing for Ultra HDTV (UHDTV) and its design and implementation as a SW tool is described. In practice, UHD video may be divided into several HD videos and each video is encoded in parallel. Therefore, it is necessary to synchronize and multiplex multiple bitstreams encoding each HD video for transmitting and storing UHD video. In this paper, it is assumed that 4 HD videos partitioning a UHD spatially are encoded as H.264/AVC and two 5.0 channel audios are encoded by AC-3. Therefore, 4 H.264/AVC elementary streams (ESs) and 2 AC-3 ESs is mainly considered in the TS multiplexing of UHD. For the carriage of H.264/AVC and AC-3 over MPEG-2 TS, PES packetization and TS multiplexing are designed and implemented based on the extended specification of the MPEG-2 Systems and ATSC (Digital audio compressed standard), respectively. The implemented UHD TS multiplexing tool emulates real time HW operation in the time unit corresponding to the duration of one TS packet transmission in a given TS rate. In particular, in order to satisfy the timing model, the buffers defined in the TS System Target Decoder (T-STD) are monitored and their statuses are considered in the scheduling of TS multiplexing. For UHD multiplexing, two kinds of multiplexing structures, which are UHD re-multiplexing and UHD program multiplexing, are implemented and their strength and weakness are investigated. The developed UHD TS multiplexing tool is tested and verified in terms of the syntax and semantics conformance and functionalities by using a commercial analyzer and real-time presentation tools.

• Journal of Internet Computing and Services
• /
• v.16 no.2
• /
• pp.19-26
• /
• 2015

Operating on its own to develop a system or based on the standard to setup and operating of RFID System. If you want to operate RFID system yourself then It is no problem to use its own to develop a system, but have to implementation RFID System based standard for the system integration and data linkage in multiple companies or base. In this paper, I propose an EPCIS Capturing Application of the element for applying an RFID-based EPC Network as an international civil standards organization EPCglobal. EPCIS Capturing Application generation is a message for transmission to EPCIS receives the data transmitted from the reader and middleware to serve to transfer the EPCIS. This paper also proposes Capture Interface capable of receiving the data of the equipment does not use the ALE Interface as a portable RFID reader ALE Interface, as well as used by the RFID reader to implement a fixed system for use in the field. In this paper, we propose a EPCIS Capturing Application for tracking the history RFID is applied to the finished product. It is possible to take advantage to be applied to all systems based on the EPCglobal standard through proposed the EPCIS Capturing Application.

• The Journal of the Korean Society for Microbiology
• /
• v.19 no.1
• /
• pp.11-24
• /
• 1984

Shigella remains to be an important enteric pathogen in this country for the present. Moreover, most of the isolates have become multiple resistant to various antibiotics which used to be drugs of choice for shigellosis. This study was made as an attempt to assess the present stage of antibiotic resistance and the incidence and transferability of R factors of Shigella. A total of one hundred and seventeen strains of Shigella isolated from patients in Seoul and provincial area between 1982 and 1983 were tested for their resistant to antimicrobial agents and transmission of R-plasmid. Antibiotic susceptibilities were determined by an agar dilution method. Muller hinton agar were used for the assay of drug resistance and tryptic soy broth were used for propagating medium for conjugation. Shigella isolated found to be one or more antibiotics were considered potential donor of R-plasmid. The following results were obtained. 1. Among 117 strains of Shigella isolated, 111 strains(94.9%) were found to be resistant to one or more drugs tested and 97.3% of these resistant strains were multiply resistant, indicating the multiply resistant strains were more than the single resistant strains. Only six strains were susceptible to all drugs tested. 2. Among 117 strains of Shigella isolated, 107 strains(91.5%) were resistant to Tetracyclin(Tc), 106 strains(90.6%) to Chloramphenicol(Cp) and Streptomycin(Sm), 97 strains(82.9%) to Ampicillin(Ap), 68 strains(58.1%) to Cephaloridine(Cr), 10 strains(8.5%) to Nalidixic acid(Na), 5 strains(4.3%) to Kanamycin(Km) and 2 strains(1.7%) to Rifampicin. No strain was resisfant to Amikacin(Ak) and Gentamicin(Gm). 3. All drug-resistant Shigella strains, except three, were multiply resistant to two or more drugs. Fifty eight strains were resistant to five drugs, followed by 26 strains resistant to dour drugs, 12 strains resistant to three drugs and 11 strains resistant to six drugs. 4. The 73% of multiply drug-resistant Shigella transferred their resistance to E. coli by conjugation and the resistance was considered to be mediated by R-plasmid. Resistance to Nalidixic acid and Rifampicin were not transferred by conjugation to recipient. As for the transferability of resistance to each seperate drug, Ap resistance was transferred with 73.2% frequence and Cm and Tc resistance were transferred with approximately 50-60% frequence whereas Sm and Cr resistance were transferred in 19.1-21.4% The other four drugs resistant failed to transfer their resistance to recipient. 5. As for the incidence and transferability of resistance to each seperate drug, the strains resistant to Tc and Cm were encountered most frequently with the rate of 91-92%, whereas transfer of Tc and Cm were low, 51-52%. The incidence of Sm resistance was very high(90.6%) but transferability of drugs resistance was much lower(25.4%). Though the incidence of Km reristance was much lower(4.3%) transferability of Km resistance was considerably higher(60%). 6. The greater the multiplicity of resistance, the greater was the likelihood that part of all of the resistance markers would be transferable.