• East Asian mathematical journal
• /
• v.38 no.1
• /
• pp.65-84
• /
• 2022

This paper is based on Yanbian University's physical test data, and uses statistical analysis methods to study the relationship between college students' physical test scores to promote college physical education. Firstly, using gender as categorical variables, we conduct a general analysis of students in different majors and different grades, and obtain the advantages and disadvantages of male and female college students; then we use Decision Trees and Random Forest algorithms to conduct modeling analysis to provide valuable suggestions for relevant departments of the university. the aiming of this research analyzing about the undergraduates physical test is that giving universities the targeted suggestions to improve the college graduate rate and promote the overall development of higher education, lay the foundation for achieving universal health.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.47 no.4
• /
• pp.75-87
• /
• 2010

For two input-protection schemes suitable for RF ICs utilizing the thyristor and diode protection devices, which can be fabricated in standard CMOS processes, we attempt an in-depth comparison on HBM ESD robustness in terms of lattice heating inside protection devices and peak voltages developed across gate oxides in input buffers, based on DC, mixed-mode transient, and AC analyses utilizing a 2-dimensional device simulator. For this purpose, we construct an equivalent circuit for an input HBM test environment of a CMOS chip equipped with the input ESD protection circuits, which allows mixed-mode transient simulations for various HBM test modes. By executing mixed-mode simulations including up to six active protection devices in a circuit, we attempt a detailed analysis on the problems, which can occur in real tests. In the procedure, we suggest to a recipe to ease the bipolar trigger in the protection devices and figure out that oxide failure in internal circuits is determined by the junction breakdown voltage of the NMOS structure residing in the protection devices. We explain the characteristic differences of two protection schemes as an input ESD protection circuit for RF ICs, and suggest valuable guidelines relating design of the protection devices and circuits.

• Journal of Radiation Protection and Research
• /
• v.35 no.4
• /
• pp.151-156
• /
• 2010

The types of test items which were recorded in this test report of quality control domestic $^{18}F$-FDG radiopharmaceutical which consisted of 13 different types: appearance, half-life, radioactive heterokaryosis, radiochemical Confirmation (measure of Rf value), radiochemical Purity, Ethanol, Acetonitrile, Kryptofix, Aluminium, pH, Endotoxin, aseptic test, and radioactivity${\cdot}$ml-1. The record was fully recorded in 'appearance', 'radioactive heterokaryosis', 'pH', 'Endotoxin', and 'aseptic test'. In 'half-life', 'radiochemical Confirmation (measure of Rf value), 'radiochemical Purity', 'Ethanol', 'Acetonitrile', 'Kryptofix', 'Aluminium', 'radioactivity${\cdot}$ml-1', there were differences in records of each manufacturing business on radioactive medicine and medical supplies. The result of the test showed all 13 items of quality control test were 100% suitable on the basis of recorded data. There were more radiopharmaceutical made in the laboratory than in hospitals and businesses and in for result of suitability test, the laboratory showed higher suitability than did the hospitals or businesses. Domestically, there are differences of the test report items in the safety of radiopharmaceutical of each facility, and since it is not standardized, supplements are needed. To submit standardized test reports of quality guarantee in radiopharmaceutical, GMP of U.S. and CE Mark of Europe should be referred as well as receiving advice from professionals to standardize as suitable domestic standard.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.36 no.12
• /
• pp.1207-1215
• /
• 2008

Satellite generates a complex electromagnetic noise by conducted and radiated coupling effect of the various electrical instruments. This noise may cause serious problems on the satellite system. To minimize the electromagnetic coupling effects and maintain the system safety margin, system noise reduction technique should be applied from the beginning of the system design. The COMS system is evaluated by measuring the conducted noise on system electrical power leads at PSR(Power Supply Regulator) and verifying a 6 dB system safety margin under the complex noise environment with current injection. The radiated noise due to the complex transmit antenna configuration is evaluated by integrating all unit-level RE measurement results, and the RF compatibility between spacecraft and launch vehicle is analyzed with the above estimations. This paper describes the COMS EMC compatibility analysis with respect to each unit level EMC test results, and RF compatibility analysis between spacecraft and launch vehicle. The analyzed results will be reflected on FM(Flight Model) EMC test.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.46 no.2
• /
• pp.24-30
• /
• 2009

In this paper, the FPGA modem platform complying with 3GPP Release 7 eHSPA specifications and its regularized verification flow are proposed. The FFGA platform consists of modem board supporting physical layer requirements, MCU and DSP core embedded control board to drive the modem board, and peripheral boards for RF interfacing and various equipment interfaces. On the other hand, the proposed verification flow has been regularized into three categories according to the correlation degrees of hardware-software inter-operation, such as simple function test, scenario test call processing and system-level performance test. When it comes to real implementations, the emulation verification strategy for low power mobile SoC is also introduced.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.22 no.6
• /
• pp.577-583
• /
• 2011

Radar performance test is one of the major steps for radar system design. However, it is restricted by time and cost when radar performance tests are performed with opportunity targets. So various simulated target generators are developed and used to evaluate radar performance. To simulate the target's range, most of simulated target generators are developed with optical line or DRFM(Digital RF Memory) technique but there are many restrictions such as limit of range imitation and test scenario because of their original usage. In this paper, DDL(Digital Delay Line) module for development of simulated target generator is designed with precise range simulation and easily embodiment feature. And pulse recognition and delay gap detection technique are used to simulate the time delay without distortions. Developed DDL module performances are verified through their performance tests and test results are described in this paper.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.20 no.5
• /
• pp.51-56
• /
• 2020

Measurement accuracy and required time is important to make ATE(Automatic test equipment) system in Ka band, and SCPI commands of power meter which is a representative RF test equipment are studied in this paper. Comparison data between FETCH and MEASURE which are SCPI commands are measured in 30 G ~ 31 GHz and -70 ~ +20 dBm using two power sensor. The data show that FETCH which is the fastest SCPI is able to get reliable data in linear interval above noise level. MEASURE which is the best accurate command takes longer time than FETCH, and the longest time is 13.2 seconds. These results offer that measurement accuracy and required time of the two SCPI for power meter and would be used as a guideline for efficient ATE system in Ka band.

• Journal of Navigation and Port Research
• /
• v.30 no.4
• /
• pp.291-294
• /
• 2006

Corrosion is never avoided in the use rf materials with various environments. The underwater hull is normally protected against rusting by several coatings of anti-corrosive paint. The purpose of ICCP(Impressed Current Cathodic Protection) system is to eliminate the rusting or corrosion, which occurs on metal immersed in seawater. This thesis is about the ICCP control and monitoring system, which brings protection against the corrosion of the ship's hull in the sea environments. The test system for ICCP is composed of a power supply, anode, reference electrode and controller. The test system is composed power supply, anode, ref electrode, shunt and etc. The protection current is sent to the protection area though anode. Reference electrode senses whether or not the detected potential is within a range of protection of test equipment and then it is automatically controlled to increase or decrease the amount of protective current to be sent to the anode by controller. The monitoring system with LabView is also detected in order to check the normal state of the system at operation period, because an operator does not always watch over this system and thus the system cannot operate well because rf his or her negligent management. This paper was studied the variation of potential and current density with environment factors, velocity and time, and the experimental results will be explained Also, It is suggested that this system can accommodate a ship's automation for SCMS(Ship Control and Management System) and will be very useful.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2008.10a
• /
• pp.196-203
• /
• 2008

Durability of geosynthetics for soil reinforcement is accounted for creep and creep rupture, installation damage and weathering, chemical and biological degradation. Among these, the long-term creep properties have been considered as the most important factors which are directly related to the failure of geosynthetic-reinforced soil(GRS). However, the creep test methods and strain limits are too various to compare the test results with each other. The most widely used test methods are conventional creep test, time-temperature superposition and stepped isothermal method as accelerated creep tests. Recently developed design guidelines recommend that creep-rupture curve be used to determine the creep reduction factor($RF_{CR}$) which is a conservative approach. In this study, the different creep test methods were compared and the creep reduction factors were estimated at different creep strain limits of 10% of total creep strain and creep rupture. In order to minimize the impact of creep strain to the GRS structures, the various creep reduction factors using different creep test methods should be investigated and then the most appropriated one should be selected for incorporating into the design.

• Journal of Life Science
• /
• v.32 no.8
• /
• pp.622-632
• /
• 2022

The purpose of this study was to investigate activities as functional cosmetic materials, focusing on Rhododendron brachycarpum (RB) and Rhododendron fortunei (RF). The tyrosinase inhibitory effect, related to skin-whitening, was 32.6% and 39.3% respectively at the concentration of 1,000 ㎍/ml. The elastase inhibitory effect, related to skin anti-wrinkling activity, was 30% and 36.2% at 1,000 ㎍/ml concentration. Collagenase inhibitory activity showed 77.7%, and 80.2% respectively at 1,000 ㎍/ml concentration, which demonstrated excellent inhibitory activity. For a cell viability test, that measured on fibroblast cells by RB and RF extracts. Furthermore, the cell viability test showed 100.9% and 98.9% with cell viability at 100 ㎍/ml concentration in CCD-986Sk. The protein expression inhibitory effect of RB and RF extracts was measured by western blot at 25, 50, and 100 ㎍/ml concentrations, and the β-actin was used as a positive control. As a result, western blot of RB and RF extracts was measured by the expression inhibition rate of the MMP-1, MMP-2, MMP-3 protein, and was decreased by 67.2%, 65.5%, 13.6%, and 89.1%, 85.0%, and 62.7% at 100 ㎍/ml concentration. The mRNA expression inhibitory effect of RB and RF extracts was measured by RT-PCR at 25, 50, and 100 ㎍/ml concentrations, and the GAPDH was used as a positive control. According to the results of RT-PCR of RB and RF extracts, the expression inhibition rate of the MMP-1, MMP-2, and MMP-3 mRNA was decreased by 70.1%, 9.1%, 37.9%, and 38.2%, 8.3%, 57.3% at 100 ㎍/ml concentrations. So, RB and RF extracts showed the anti-wrinkle effectiveness as a functional cosmetic material.