• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.23 no.1
• /
• pp.47-55
• /
• 2012

This paper describes the developed HILS and test equipment in order to test the performances of MMW(Millimeter-Wave) seeker which can detect and track a high speed of short-range ballistic missile and aircraft. This system is used to 141 horn antenna array, array switching, and gain and phase control algorithm to simulate various kind of targets and trajectory of high speed and maneuver moving target. In addition, it simulates not only velocity and range for these targets but also clutter and jamming environments. System configuration and implementation and the measurement results of major subsystems such as target motion simulator, simulation signal generator, high speed data aquisition unit, and central control unit are presented. These systems could verify the detection and tracking performance of MMW seeker through dynamic real-time test based on simulation flight scenario.

• Journal of the Korean Geotechnical Society
• /
• v.21 no.9
• /
• pp.65-75
• /
• 2005

Maximum shear modulus of soil is a principal parameter for the design of earth structures under static and dynamic loads. In this study, the statistical data of maximum shear moduli of silty sands in Songdo area in the west coast of Korea evaluated by various field and laboratory tests - standard penetration test (SPT), cone penetration test (CPT), self-boring pressuremeter test (SBPT), downhole test (DH), seismic cone penetration test (SCPT) and resonant column test (RC) were analyzed. Based on the measurement of shear moduli using DH which is known as maximum value at very small strain, the new empirical correlations between shear moduli and SPT or CPT values were proposed. Predictions of maximum shear moduli using the proposed correlations were compared with the data obtained from DH. The good agreement confirmed that the proposed correlations reasonably predicted the maximum shear moduli of silty sands in the area.

• Journal of KIISE
• /
• v.42 no.4
• /
• pp.427-433
• /
• 2015

The rapid advancement of computing technology has triggered the need for fast data I/O processing and high-performance storage technology. Next generation memory technology, which we refer to as new memory, is anticipated to be used for high-performance storage as they have excellent characteristics as a storage device with non-volatility and latency close to DRAM. This research proposes NTL (New memory Translation layer) as a technology to make use of new memory as storage. With the addition of NTL, conventional I/O is served with existing mature disk-based file systems providing compatibility, while new memory I/O is serviced through the NTL to take advantage of the byte-addressability feature of new memory. In this paper, we describe the design of NTL and provide experiment measurement results that show that our design will bring performance benefits.

• Journal of KIISE:Software and Applications
• /
• v.36 no.1
• /
• pp.1-9
• /
• 2009

In heterogeneous and distributed computing environments, with an increasing number of Web services providing similar functionalities, the reliability of Web services is a critical decision factor. To fulfill the open business model such as cooperation among enterprises, several Web services can be composed into the upper level business transaction. In Web services composition, the reliability of services is more and more critical. Though each unit Web service can be reliable, the reliability of the composed service is not guaranteed. Thus a way to efficiently assess and select composed Web services is needed. In this paper, we define new metrics for measuring the trust value of Web services, and propose an evaluation method to predict the trustworthy degree of the composed services based on the metrics. We also define a conceptual framework to support optimal Web services selection based on the proposed trust evaluation method. By selecting using the quantitative measurement rather than intuitive selection of the service user, it allows the service users to select the high reliable service meeting their quality requirements well.

• Atmosphere
• /
• v.18 no.4
• /
• pp.267-277
• /
• 2008

The occurrence and strength of the Asian Dust over the Korea Peninsular have been increased by the expansion of the desert area. For the continuous monitoring of the Asian Dust event, the geostationary satellites provide useful information by detecting the outbreak of the event as well as the long-range transportation of dust. The Infrared Optical Depth Index (IODI) derived from the MTSAT-1R data, indicating a quantitative index of the dust intensity, has been produced in real-time at Korea Meteorological Administration (KMA) since spring of 2007 for the forecast of Asian dust. The data processing algorithm for IODI consists of mainly two steps. The first step is to detect dust area by using brightness temperature difference between two thermal window channels which are influenced with different extinction coefficients by dust. Here we use dynamic threshold values based on the change of surface temperature. In the second step, the IODI is calculated using the ratio between current IR1 brightness temperature and the maximum brightness temperature of the last 10 days which we assume the clear sky. Validation with AOD retrieved from MODIS shows a good agreement over the ocean. Comparison of IODI with the ground based PM10 observation network in Korea shows distinct characteristics depending on the altitude of dust layer estimated from the Lidar data. In the case that the altitude of dust layer is relatively high, the intensity of IODI is larger than that of PM10. On the other hand, when the altitude of dust layer is lower, IODI seems to be relatively small comparing with PM10 measurement.

• The Journal of Korean Physical Therapy
• /
• v.27 no.4
• /
• pp.240-245
• /
• 2015

Purpose: The purpose of this study was to compare the blocked practice and random practice of task-oriented training in patients with chronic stroke to determine the effect of lower extremity muscle activity and balance ability. Methods: The thirty participants were randomly assigned to either the block practice group (BP) group or the random practice group (RP) and received the training three times per week, 30 minutes per day, for six weeks. Surface electromyography was used for measurement of lower extremity muscle activity. Static balance was to measured the stability index (SI) and weight distribution index (WDI) using the Tetrax. The four square step test (FSST) was used to measure dynamic balance. The paired t-test was used for determination of differences before and after intervention, and the independent t-test was used for determination of differences between groups. Results: Lower extremity muscle activity, RA and GCM was improved in the RP group after intervention and between groups. TA was significantly improved in the RP group compared with the BP group. In comparison of before and after interventions, SI was reduced in BP and RP. WDI in OS was reduced in comparison of BP and RP before and after intervention. CS was reduced in BP and RP. The OS and CS was improved in RP compared with BP. In comparison of before and after intervention, FSST was improved in BP and RP. Conclusion: Task-oriented training methods using random practice was found to be effective in promoting lower extremity muscle activity and balance ability in chronic stroke patients.

• The Korean Journal of Nuclear Medicine
• /
• v.23 no.2
• /
• pp.209-214
• /
• 1989

Yasculogenic impotence is produced by abnormalities of vascular blood supply or drainage, and is the most common cause of various organic impotences. An increasing awareness of vascular causes of impotence has resulted from development of various diagnostic tests, but precise measurement of penile blood flow is difficult. Radionuclide penogram has been introduced recently to diagnose vasculogenic impotence. Forty-one impotent patients and 12 normal men were studied with radionuclide erection penogram using Tc-99m pertechnetate and an intracavernous injection of papaverine. We defined arteriogenic impotence as arterial index less than 0.66, and venogenic impotence as venous index greater than 0.09. By this criteria, the false positive ratio in normal men was 17%, and the false negative ratio in radically cystectomized patients was 0%. Side effects were small purpura of the penile shaft and dull pain during injection of papaverine. The radionuclide erection penogram was noninvasive and gave a dynamic evaluation of the arterial supply, venous drainage, and blood flow in the corporeal bodies. This method should be considered as a valuable adjunct to evaluate patients with vasculogenic impotence.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.25 no.5
• /
• pp.713-721
• /
• 2001

Characteristics of the conical vortices on the roof corner of a rectangular prism have been investigated by using a PIV(Particle Image Velocimetry) technique. The Reynolds number based on the free stream velocity and the height of the model was 5.3$\times$10$^3$. The mean, instantaneous velocity vector fields, vorticity fields, and turbulent kinetic energy distribution were measured for two different angles of attack, 30$^{\circ}$and 45$^{\circ}$. The PIV measurements clearly observed not only the conical main vortex and the secondary vortex but also the tertiary vortex which is firstly reported in this paper. Asymmetric formation of the corner vortex for the case of 30$^{\circ}$angle of attack produces relatively the high magnitude of vorticity and turbulent kinetic energy around the bigger vortex which generates the peak suction pressure on the roof. Fairly symmetric features of the roof vortex are observed in the case of 45$^{\circ}$angle of attack, however, the dynamic characteristics are proved to be asymmetric due to the rectangular shape of the roof.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2006.05a
• /
• pp.1334-1337
• /
• 2006

System identification is the field of modeling dynamic systems from experimental data. As a modeling technique, we can mention finite element method (FEM). In addition, we are able to measure modal data as the experimental data. The system can be generally categorized into a gray box and black box. In the gray box, we know mathematical model of a system, but we don't know structural parameters exactly, so we need to estimate structural parameters. In the black box, we don't know a system completely, so we need to identify system from nothing. To date, various system identification methods have been developed. Among them, we introduce system realization theory which uses Hankel matrix and Eigensystem Realization Algorithm (ERA) that enable us to identify modal parameters from noisy measurement data. Although we obtain noise-free data, however, we are likely to face difficulties in identifying a structure with hidden modes. Hidden modes can be occurred when the input or output position comes to a nodal point. If we change a system using a mode decoupling controller, the hidden modes can be revealed. Because we know the perturbation quantities in a closed loop system with the controller, we can realize an original system by subtracting perturbation quantities from the closed loop system. In this paper, we propose a novel method to identify a structure with hidden modes using the mode decoupling controller and the associated example is given for illustration.

• Korean Journal of Environmental Biology
• /
• v.32 no.4
• /
• pp.327-334
• /
• 2014

Emission reduction of $CH_4$ (methane gas) from rice paddy soil is a very important measure for climate change mitigation in agricultural sector. In this study, we investigated the changes in crop yield and $CH_4$ emissions in response to application of biochar and fertilizers. The experimental site is located in Hwasung, Kyunggido and experimental design is the split-plot method with three replicates. Treatments included rice straw (RS) and biochar (BC) amendments nested with the conventional NPK fertilizer (NPK) and slow release fertilizer (SRF). Control was also prepared with the soil with the conventional NPK fertilization with no amendment. Measurement of $CH_4$ emission was conducted during the growing season of 2014 using a dynamic chamber method. The results showed that application of rice straw increased daily $CH_4$ emission rate by 15%, while application of biochar reduced daily $CH_4$ emission rate by 38%. When we combined biochar application with slow release fertilizer, $CH_4$ emission was reduced by 45%. Further, the crop yield was also increased in all treatments compared with the control except for the treatment of rice straw application with slow release fertilizer. Overall results imply that biochar amendment to agricultural soil can be an effective strategy to decrease annual $CH_4$ emission with no reduction in crop yield.