• The Journal of Korean Institute of Communications and Information Sciences
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• v.33 no.4A
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• pp.387-393
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• 2008

In this paper, we present an SDR (Software Defined Radio) handset modem platform which supports communication systems such as HSDPA (High Speed Downlink Packet Access), and WiBro (Wireless Broadband Portable Internet). The proposed SDR platform employs DSPs (Digital Signal Processors), FPGAs (Field Programmable Gate Arrays), and microprocessors in such a way that the various communication functions like HSDPA and WiBro can be programmed and downloaded to the hardware platform. The proposed SDR platform can be used for functional verification of the physical layers of the mobile handset system in the mobile communication network. We first demonstrate the receiving structure of the physical layer of the HSDPA and WiBro system. Then, the hardware implementation of the proposed SDR platform is shown with functions and optimized signal flows required at each mode. Finally, the link performance of each mode operating on the proposed SDR platform is presented through the internal loopback tests with the test vectors. The experimental performance has been compared with the computer simulation results.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.7
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• pp.37-43
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• 2010

As the speed of A/V streaming, the transmission-speed requirement of serial link is continuously increasing. Consequently, commercial standards, which are released previously, are increasing transmission speed in their newly-updated versions. The flexibility between previous and updated versions is very important requirement, therefore, the transceiver which can operates at more than one data rate is important market demand. This paper demonstrates 4-channel 3.2/ 6.4 Gbps transmitter, which is capable of selecting 1, 1.5, 2, and 3 times of pre-emphasis and 200, 300, 400, and 600 mVdiff,p2p of output swing. The prototype chip was fabricated using $0.13{\mu}m$ CMOS process. Its performances are verified on PCB using COB packaging.

• Journal of KIISE:Information Networking
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• v.29 no.3
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• pp.277-285
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• 2002

This paper proposes and analyzes an error control scheme for the transmission control based real-time communication, such as FDDI, TDMA, and wireless LAN, which delivers the message according to the round robin fashion after the off-line bandwidth allocation. Taking into account the time constraint of each message, the proposed error control scheme makes the receiver transmit the error report via asynchronous traffic while the sender resend the requested message via overallocated access time which is inevitably introduced by the bandwidth allocation procedure for hard real -time guarantee. The error control procedure does not interfere other real -time message transmissions. In addition, as each frame contains the size of the message it belongs, the receiver can recognize the end of completion of message transmission. This enables earlier error report to the receiver so that the sender can cope with more network errors. The analysis results along with simulation performed via SMPL show that the proposed scheme is able to enhance the deadline meet ratio of messages by overcoming the network errors. Using the proposed error control scheme, the hard real -time network can be built at cost lower than, but performance comparable to the expensive dual link network.

• Environmental Engineering Research
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• v.18 no.4
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• pp.277-281
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• 2013

A dual-chamber microbial fuel cell (MFC) inoculated with Desulfovibrio desulfuricans and supplemented with lactate as an organic fuel was employed in this study. Biofilm formed on the anodic electrode was examined by scanning electron microscopy, revealing that the amount of biofilm was increased with repeated cycles of MFC operation. The maximum current production was notably increased from the first cycle ($1,310.0{\pm}22.3mA/m^2$) to the final cycle ($1,539.4{\pm}25.8mA/m^2$) of MFC run. Coulombic efficiency was also increased from $89.4%{\pm}0.2%$ to $98.9%{\pm}0.5%$. We suggest that the current production efficiency was related to the biomass of biofilm formed on the electrode, which was also increased as the MFC run was repeated. It was also found that D. desulfuricans, which colonized on the electrode, produced filaments or nano-pili. Nano-pili were effective for the attachment of cells on the electrode. In addition, the nano-pili provided a cell-to-cell link and stimulated the development of thicker electroactive biofilm, and therefore, they facilitated electron transfer to the anode. Conclusively, the biofilm of D. desulfuricans enhanced the current production in the MFC as a result of effective attachment of cells and electron transfer from the cell network to the electrode.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.23 no.2
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• pp.101-108
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• 2005

Inertial Navigation System has been used extensively to determine the position, velocity and attitude of the body. An INS is very expensive, however, heavy, power intensive, requires long setting times and the accuracy of the system is degraded as time passed due to the accumulated error. Global Positioning System(GPS) receivers can compensate for the Inertial Navigation System with the ability to provide both absolute position and attitude. This study describes a method to improve both the accuracy of a body positioning and the precision of an attitude determination using GPS antenna array. Existing attitude determination methods using low-cost GPS receivers focused on the relative vectors between the master and the slave antennas. Then the positioning of the master antenna is determined in meter-level because the single point positioning with pseudorange measurements is used. To obtain a better positioning accuracy of the body in this research, a wireless internet is used as an alternative data link for the real-time differential corrections and dual-frequency GPS receivers which is expected to be inexpensive was used. The numerical results show that this system has the centimeter level accuracy in positioning and the degree level accuracy in attitude.

• Journal of Advanced Navigation Technology
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• v.23 no.5
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• pp.430-436
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• 2019

It is needed to develop an antenna with features of subminiature, light weight and multi-band operation for the variaty services in maritime and industrial fields. The PCB pattern antenna is one of the appropreiate antennas solving these requirements. In this research, the design and fabrication of the PCB pattern antenna operating on the single band of 920 MHz are investigated. The final goal is that the development of the dual band PCB pattern antenna operating on 260 MHz and 920 MHz, which is based on the proposed antenna. It is evident that the performance in the frequencies of 902 MHz, 915 MHz and 928 MHz among of 920 MHz ISM band is better than that in other frequencies. It is also confirmed that the differences of the voltage standing wave ratio, return loss, gain and efficiency between three frequencies are less than 5%. It is expected that the development of communication link of 5-10 km is possible when the induced results are applied into the low power wide area (LPWA) network desinged by the rule of -30 dB sensitivity.

• Journal of Multimedia Information System
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• v.9 no.2
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• pp.145-154
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• 2022

The authors are making a prototype flexible board of a radio-frequency transmitter for measuring an electromyogram (EMG) of a flying moth and plan to apply for an experimental station license from the Ministry of Internal Affairs and Communications of Japan in the summer of 2022. The goal is to create a continuous low-dose exposure standard that incorporates scientific and physiological functional assessments to replace the current standard based on lethal dose 50. This paper describes the technical evaluation of the hardware. The signal of a bipolar EMG electrode is amplified by an operational amplifier. This potential is added to a voltage-controlled crystal oscillator (27 MHz, bandwidth: 4 kHz), frequency-converted, and transmitted from an antenna about 10 cm long (diameter: 0.03 mm). The power source is a 1.55-V wristwatch battery that has a total weight of about 0.3 g (one dry battery and analog circuit) and an expected operating time of 20 minutes. The output power is -7 dBm and the effective isotropic radiated power is -40 dBm. The signal is received by a dual-whip antenna (2.15 dBi) at a distance of about 100 m from the moth. The link margin of the communication circuit is above 30 dB within 100 m. The concepts of this hardware and the measurement data are presented in this paper. This will be the first biological data transmission from a moth with an official license. In future, this telemetry system will improve the detection of physiological abnormalities of moths.

• The Journal of Asian Finance, Economics and Business
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• v.9 no.2
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• pp.61-69
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• 2022

The study intends to investigate a short-run and a long-run causality among money, income, and prices in the Keynesian and Monetarists framework. This study emphasizes the importance of unrecorded money, which exists alongside legal monetary assets and plays a dual function in determining economic prosperity. The underground economy, which is a hidden component of aggregate economic activity, is determined using Tanzi's monetary approach (Tanzi, 1980). This research uses a time series of annual data from 1990 to 2019 for this purpose. The data is extracted from the World Bank database for the monetary and development indicators. The study keeping in view the trending nature in data follows a unit root testing followed by the Autoregressive Distributive Lag Model (ARDL) to assess the long and short-run dynamics of causality among the variables. In both the pricing and income equations, the study finds a significant level link among the variables; however, there is no evidence of the presence of a level association in the money equation. The short-run causal relationship provides evidence of bi-directional causation between the supply of money and national income. The outcome of this study advise that though the view point of both the Monetarist and Keynesian school holds in both short and long run, however, in Pakistan only the Monetarists' role of money supply and income holds in Pakistan. This evidence would be of precise interest to the policy-makers.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.4
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• pp.2577-2582
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• 2013

Objectives: Interleukin (IL) -10 is a potent cytokine with a dual ability to immunosuppress or immunostimulate. We aimed to explore the association of IL10 promoter polymorphisms with risk of gastric cancer (GC) in a Han population in Southwestern China. Methods: We enrolled 308 pairs of GC and control subjects from four hospitals and a community between October 2010 and August 2011 in a 1:1 matched case-control design. Demographic information was collected using a designed questionnaire. IL10-592 A>C and IL10-1082 A>G polymorphisms were determined by Sequenom MassARRAY analysis. Results: Patients with GC reported statistically higher proportions of family history of cancer (29.9% versus 10.7%, P<0.01) and alcohol drinking (54.6% versus 43.2%, P<0.01) than did controls. Similar results were observed in comparison between non-cardia GC patients and controls (P<0.01 and P=0.03). Variant genotypes of IL10-592 A>C and IL10-1082 A>G were not associated with overall GC risk (adjusted OR, 0.94, 95% CI, 0.66-1.33; adjusted OR, 1.00, 95% CI, 0.62-1.60). Sub-analysis showed that the IL10-592 AC/CC variant genotype was associated with decreased non-cardia GC risk (adjusted OR, 0.58; 95% CI, 0.36-0.95). No association was found between any of the IL10 haplotypes established from two polymorphisms and risk of non-cardia GC. Conclusions: In conclusion, our data do not link the two SNPs of IL10-592 and IL10-1082 with overall GC risk. We demonstrate that IL10-592 polymorphism is associated with protective effect against non-cardia GC. Our findings may offer insight into risk associated with the development of GC in this region.

• Korean Journal of Agricultural and Forest Meteorology
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• v.8 no.4
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• pp.275-278
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• 2006

Google Earth enables people to easily find information linked to geographical locations. Google Earth consists of a collection of zoomable satellite images laid over a 3-D Earth model and any geographically referenced information can be uploaded to the Web and then downloaded directly into Google Earth. This can be achieved by encoding in Google's open file format, KML (Keyhole Markup Language), where it is visible as a new layer superimposed on the satellite images. We used KML to create and share fine resolution gridded temperature data projected to 3 climatological normal years between 2011-2100 to visualize the site-specific warming and the resultant earlier blooming of spring flowers over the Korean Peninsula. Gridded temperature and phonology data were initially prepared in ArcGIS GRID format and converted to image files (.png), which can be loaded as new layers on Google Earth. We used a high resolution LCD monitor with a 2,560 by 1,600 resolution driven by a dual link DVI card to facilitate visual effects during the demonstration.