• Korean Journal of Veterinary Service
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• v.22 no.1
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• pp.61-70
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• 1999

This study is concerned with assessment of diethylnitrosamine(DEN) induced liver cell carcinogenesis by measurement of changes preceding the development of neoplasms. Therefore, it was undertaken to investigate the changes of liver-specific enzyme activities in rats (Sprague-Dawley) by ad libitum feeding of DEN. And also, as another objective index in urine, the level of urinary biopterin was measured by high performance liquid chromatography(HPLC) method. The results were as follows ; 1. Minor behavioral change, brittleness of hair and decreased amount of water and diet intake were observed in rats 7 weeks after DEN administration. 2. The body and liver weights were significantly(p<0.05) decreased in rats 11 weeks after DEN administration. 3. The ratio of liver weight to body weight was rather stable and not significantly decreased in the all treatment groups. 4. The liver specific enzyme activities(AST, ALT,$\gamma$-GTP) were significantly(p<0.05) increased in all treatment groups compared to control group. 5. Compared to normal level, urine biopterin level was significantly (p<0.05) increased in all treatment groups(p<0.05). In conclusion, this result confirmed that the DEN was one of the potent hepatocarcinogens. In experimental model of rats exposed to DEN, the results indicated that values of liver specific enzyme activities(AST, ALT, $\gamma$-GTP) and urine biopterin level could be useful complementary tumor indices.

• Journal of the Korean Society of Hazard Mitigation
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• v.6 no.3 s.22
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• pp.17-28
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• 2006

Structural health monitoring is important to maintain the safety and serviceability of the structures. The displacement in the structure should be precisely and frequently monitored because it is a direct assessment index indicating its stiffness. However, no practical method has been developed to monitor such displacement precisely, particularly for high-rise buildings and long span bridges because they cannot be easily accessible. To overcome such difficult accessibility, we propose to use a LIDAR system that remotely samples the surface of an object using laser pulses and generates the coordinates of numerous points on the surface. In this study, using terrestrial LiDAR, we develop a novel displacement measuring model for structural health monitoring and perform an indoor experiment to prove its performance.

• Journal of Radiation Protection and Research
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• v.17 no.1
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• pp.31-41
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• 1992

A study for the evaluation of selected filter media that need further characterization particularily in the context of alpha measurements of radon progeny has been carried out by investigating physical characteristics and using the alpha spectroscopy. Physical characteristics was investigated by electrostatic charging and mechanical strength of filters, and then pressure drop before and after sampling was tested. Alpha spectroscopy was used to analyze the energy spectra from the deposition of radon progeny into filters. The results of the assessment showed that the newer filter types do not have a great advantage over the 'old standard' Millipore type AA. But Metricel DM-800 is recommended for those situations where electrostatic charging is a problem. Also this method will be used more effective for the evaluation of new developing filters in future.

• Journal of Sensor Science and Technology
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• v.25 no.1
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• pp.35-40
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• 2016

Pulse diagnosis is one of the representative diagnostic methods in Oriental medicine. In this study, a pulse pressure sensor array coated with silicone, which includes 6 piezo-resistive sensors and 1 thermistor, is fabricated for pulse measurement. It is necessary to coat the pulse sensor array with silicone to avoid the fracture or damage of pressure sensors when the sensor is in contact with the skin and a constant pressure is applied. However, the silicone coating on the pulse sensor array can cause signal interference among the sensors in the pulse sensor array. The interference number (IN), a calculation for expressing the degree of interference among channels, is changed according to the silicone thickness on the pulse sensor array. The IN is increased by a thick silicone coating, but the fabrication error, an important index for the mass production of the sensor array, is reduced by the thickness of the silicone coating. We propose that the thickness of the silicone on the pulse sensor array is an important consideration for the performance of the fabricated sensor and manufacturing repeatability.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.12
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• pp.116-123
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• 2001

An automated injection molding design methodology has been developed to optimize multiple quality attributes, which are usually in conflict with each other, in injection molded parts. For the optimization, commercial CAE simulation tools and optimization techniques are integrated into the methodology. To decal with the multiple objective problem the relative closeness computed in TOPSIS(Technique for Order Preference by Similarity to Ideal Solution) is used as a performance measurement index for optimization multiple part defects. To attain robustness against process variation, Taguchi's quadratic loss function is introduced in the TOPSIS. Also, the modified complex method is used as an optimization tool to optimize objective function. The verification of the developed design methodology was carried out on simulation software with an actual model. Applied to production this methodology will be useful to companies in reducing their product development time and enhancing their product quality.

• Journal of the Society of Naval Architects of Korea
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• v.42 no.5 s.143
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• pp.542-549
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• 2005

Naval ships are complex weapon systems which play the integrated performance by system integration of many kinds of weapon systems and their leading ships are usually not disposed after test and evaluation but militarised. Then, strict project management is required for naval ship building projects by identifying problems early and by taking prefer measures in time against unexpected situations encountered in the process of the projects. EVMS is a project management system which can manage the schedule and the budget of a project concurrently and estimate the project's time duration and the cost at project completion. In this paper, the applicability and usefulness of WMS is studied for a assumed navai ship building project, in the environment of monetary fluctuations such as price index, wage increase rate and exchange rate.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.4
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• pp.637-644
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• 2019

This paper describes an implementation of a graph-based simultaneous localization and mapping(SLAM) method called the General Graph Optimization. The General Graph Optimization formulates the SLAM problem using nodes and edges. The nodes represent the location and attitude of a robot in time sequence, and the edge between the nodes depict the constraint between the nodes. The constraints are imposed by sensor measurements. The General Graph Optimization solves the problem by optimizing the performance index determined by the constraints. The implementation is verified using the measurement data sets which are open for test of various SLAM methods.

• Physical Therapy Rehabilitation Science
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• v.8 no.3
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• pp.141-145
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• 2019

Objective: The purpose of this study was to compare walking conditions (straight line and curved path) on walking patterns in persons who had experienced hemiplegic stroke and to determine whether if they adapt their walking pattern and performances according to changes in environmental conditions. Design: Cross-sectional study. Methods: Forty-four hemiplegic stroke survivors participated in this study. This study measured walking performance in three different walking conditions, such as straight walking, the more-affected leg in the inner curve walking, and less-affected leg in the inner curve walking conditions, and a 2-dimentional gait analysis system was used as a primary measurement. This study also measured secondary clinical factors including the Timed Up-and-Go Test, the Trunk Impairment Scale, and the Dynamic Gait Index. Results: After analyzing, cadence and step length of the less-affected side, stride length in the more-affected side, and stride length in less-affected side were significantly different among the three different walking conditions in this study (p<0.05), but other temporospatial parameters were not significant. Cadence was the largest in the straight walking condition. Step length in the less-affected side, stride length in the more-affected side, and stride length in less-affected side were also the longest in the straight walking condition. Conclusions: The results of the study suggest that hemiplegic stroke survivors show walking adaptability according to changes in walking demands and conditions, and moreover, cadence and step and stride lengths were significantly different between straight and curved walking conditions.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.51-52
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• 2021

The maintenance of educational facilities is divided into inspection and management of facility managers residing in the school and Educational Environment Improvement Projects(EEIP) to carry out maintenance work. Educational support organizations collect maintenance requests through facility inspections by school-specific facility managers, and carry out numerous maintenance projects during the year. The EEIP has the characteristic of Program Management with interrelationships between projects, not multiple projects management. The purpose of the EEIP is to eliminate the inconvenience of school facility users and increase their satisfaction, and achieving the goal is judged to be successful. Despite the importance of management and performance measurement utilizing Critical Success Factor(CSF) for the operation of successful educational facility maintenance management programs, the system for achieving the goals is insufficient. This study derives CSFs for each stage of the EEIP for the success of the EEIP. The CSFs for each stage of the EEIP is expected to serve as a basis for evaluation of educational facility maintenance management programs and can be used as an evaluation index in the future.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.1
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• pp.83-91
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• 2014

The passive UHF RFID tags for item-level tagging are now explosively used in the supply chain and retail applications as they have several advantages, the two most relevant are cost and a longer read range. However, the signal interference problem between RFID tags and smart devices in real world is expected according to the smart-phone and tablet market growth together. The performance of RFID tags can be significantly less. The popular examples are the read-success rates and read range reduction. Especially, KT Corp. recently emphasized the serious signal interference at 900 MHz of LTE and old RFID frequencies through their public demonstration. By popular demands, this paper suggests the interference tolerance measurement method between the passive UHF RFID tag and the transmitted signal from a smart device. In addition, we selected three passive UHF RFID tags(Inlay) available on the market and quantitatively evaluated read range reduction results by interference signals using the PCR(Performance Change Rates) index. As a result, the LTE system is about three times as effective as the WCDMA system in terms of interference effects, and the read range performance of two RFID tags about 60 % drop.