• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.225-226
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• 2006

As the technique of high-speed end-milling is widely adopted to machining field. The investigation for microscopic precision of workpiece is necessary for machinability evolution. The environmental pollution has become a big problem in industry and many researcher have investigated in order to preserve the environment. The environmentally conscious machining and technology have more important position in machining process. In the milling process, the cutting fluid has greatly bad influence on the environment. The damaged layer affect mold life and machine parts in machining. In this study, the cutting force, the surface roughness, micro hardness and residual stress is evaluated according to machining environment. Finally, it is obtained that the characteristics of damaged layer in environmentally conscious machining is better than that in conventional machining using cutting fluid.

• Archives of Plastic Surgery
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• v.33 no.1
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• pp.31-38
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• 2006

The effect of melatonin on morphological changes after ischemia-reperfusion injury was investigated in rat skeletal muscle. Dimethyl-sulfoxide(DMSO) was also tested for comparison. Muscle injury was evaluated in 4 groups as a single laparotomy group(control), ischemia-reperfusion group, DMSO group, melatonin group. Left hind limb ischemia was induced for 4 hours by vascular clamping of the common femoral artery and followed by 24 hours of reperfusion. The midportion of gastrocnemius muscle was taken for histological evaluation. In light microscopic study, ischemia-reperfusion group showed severe neutrophil infiltration, interstitial edema, and partial loss or degeneration of muscle fibers. The muscle tissue of melatonin group showed relatively normal architecture with mild inflammatory cell infiltration. In electron microscopic study, dilated cisternae of sarcoplasmic reticulum, dilated mitochondria with electron loose matrix and dilated cristae, disordered or loss of myofilament, indistinct A-band and I-band, intracytoplasmic vacuoles, and markedly decreased glycogen granules were observed in ischemia-reperfusion group. But relatively well maintained A-band, I-band, Z-line, M-line, and mildly dilated mitochondria with well preserved cristae were observed in melatonin group. The DMSO group showed intermediately attenuated ultrastructural changes. The results show that melatonin improves morphologically ischemia-reperfusion injury more effectively than DMSO. In conclusion, melatonin seems to be a promising agent that can salvage the skeletal muscle from severe ischemia-reperfusion injury.

• Journal of Korean Society of Transportation
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• v.13 no.1
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• pp.185-203
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• 1995

The purpose of this paper is to develop a microscopic traffic simulation model which is able to both analyze and the evaluate signlaized urban network and to verify its usefulness in comparison with the other model which has alfeady been released. This simulation model adopts the General Motor's 5th model for car-following and introduces an unique lanechanging rule using acceptable gap. It analyzes single and dual-ring signal phases and generates detector information . So it could be applied to dynamic route guidance systems as wel as real time signal control systems. The results derived from Netsim and the observed data from the real network have been used to test the validit of the proposed model. The result of the test has shown that there are no significant differences between the NETSIM model and the proposed model in estimating travel speed and stopped delay. In optimum offset estimatin , it has shown the same results with NETSIM. the measure of effectiveness , however, derived from this model is slightly better than that of the real network situation. This may be due to the fact that the proposed model does not take into account side frictions from interferences and obstacles.

• Archives of Reconstructive Microsurgery
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• v.21 no.2
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• pp.86-91
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• 2012

Purpose: Mass can compress around tissue and cause deviation of normal anatomical structures. Often, mass grows toward neurovascular pedicle and encircles depending on the nature of mature mass. Neglecting neurovascular involvement of the mass is a serious problem not to be overlooked. Authors have performed microscopic approach regarding mass involving the neurovascular pedicle in the hand. Materials and Methods: From January 2007 through February 2012, retrospective analysis for nine cases of mass involving neurovascular pedicles was done. Patients were evaluated preoperatively by ultrasonography or MRI and checked intraoperative finding. Masses were evaluated by site, preoperative evaluation, involved neurovascular pedicle, histopathologic diagnosis, complication, and recurrence. Results: The site of mass involving neurovascular pedicles was 4 cases on the wrist, 2 cases on the palm, 2 cases on the finger, 1 case on the hand dorsum. Involved neurovascular pedicles were 3 radial arteries and nerves, 3 proper digital arteries and nerves, 1 radial artery, 1 superficial branch of radial nerve, 1 common digital artery and nerve. The histopathologic diagnosis of mass were 3 ganglions, 2 giant cell tumors, 2 epidermal cysts, 1 fibroma, and 1 benign spindle tumor. There were 2 cases of recurrence and secondary excisions were performed. Conclusion: Neurovascular pedicle injury can lead to serious complication like sensory and motor disorders, distal part ischemia, and so on. In case of mass suspected neurovascular invasion, accurate preoperative evaluation such as ultrasonography or MRI is necessary. To prevent any neurovascular related complication during mass excision, delicate surgical technique using a microscope becomes essential.

• Journal of Korean Society of Transportation
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• v.22 no.2 s.73
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• pp.95-102
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• 2004

The COSMOS is an adaptive traffic control systems that can adjust signal timing parameters in response to various traffic conditions. To evaluate the performance of the COSMOS systems, the field study is only practical option because any evaluation tools are not available. To overcome this limitation, a newly integrated interfacing simulator between a microscopic simulation program and COSMOS was developed. In this paper, a detector module and a signal timing module as well as general feature of the simulator were described. A validation test was performed to verify the accuracy of the data flow within the simulator. It was shown that the accuracy level of information from the simulator was high enough for real application. Several practical comments on further studies were also included to enhance the functional specifications of the simulator.

• Proceedings of the Korean Reliability Society Conference
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• 2001.06a
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• pp.235-238
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• 2001

It is well known that the reliability of materials of mechanical products is becoming more and more important not only for assurance of quality, but for international competition of products. In order to assure the reliability of materials or mechanical products nondestructive evaluation (NDE) techniques are playing more important roles. The existence of Internal defects in materials or mechanical parts is served as crack initiation site during the various loading condition. Historically, nondestructive evaluation (NDE) technique has been used almost exclusively for detecting microscopic discontinuities In materials or mechanical parts after they have been in service to expand the role of the NDE to include all aspects of materials production and application. Research efforts are being directed at developing and perfecting NDE techniques capable of monitoring (1) materials production processes (2) material integrity following transport, storage and fabrication and (3) the amount and rate of degradation during service. In addition, efforts are underway to develop technique capable of quantitative discontinuity sizing, permitting determination of response using fracture mechanics analysis, as well as techniques for quantitative materials characterization to replace the qualitative techniques used in the past. In this paper, the important role of NDE technology for reliability assurance of materials/mechanical parts is introduced.

• Journal of radiological science and technology
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• v.46 no.3
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• pp.207-217
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• 2023

Image noise reduction algorithm performs important functions in light microscopy. This study aims to systematically review the research trend of types and performance evaluation methods of noise reduction algorithm in light microscopic images. A systematic literature search of three databases of publications from January 1985 to May 2020 was conducted; of the 139 publications reviewed, 16 were included in this study. For each research result, the subjects were categorized into four major frameworks-1. noise reduction method, 2. imaging technique, 3. imaging type, and 4. evaluation method-and analyzed. Since 2003, related studies have been conducted and published, and the number of papers has increased over the years and begun to decrease since 2016. The most commonly used method of noise reduction algorithm for light microscopy images was wavelet-transform-based technology, which was mostly applied in basic systems. In addition, research on the real experimental image was performed more actively than on the simulation condition, with the main case being to use the comparison parameter as an evaluation method. This systematic review is expected to be extremely useful in the future method of numerically analyzing the noise reduction efficiency of light microscopy images.

• Reproductive and Developmental Biology
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• v.28 no.3
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• pp.167-172
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• 2004

This study was performed to examine the correlations among dog sperm viabilities evaluated by flow cytometry, by microscopic evaluation (ME), by carbo-xifluorescein diacetate and propidium iodide (CFDA/PI) and by hypoosmotic swelling (HOS) test. Semen were collected from 5 dogs ranging in age from 2 to 4 years. Each ejaculate was divided into 3 aliquots and different proportions of freeze-killed cells were added to each aliquot (1:0, 1:1 and 1:3). In the other experiment, semen was extended with Sweden extender containing 5% glycerol and equex STM paste, and frozen using liquid nitrogen vapor. Fresh and frozen-thawed dog sperm viability were assessed by flow cytometry using PI staining method. The accuracy of flow cytometry was evaluated by comparing with other classic assessments, microscopic evaluation, epifluorescence microscopic analysis using CFDA/PI, and HOS test. High correlations of sperm viabilities were found among flow cytometry, epifluorescence evaluation, HOS test (p<0.01) in fresh semen. Especially, sperm viability assessed by HOS test was highly correlated with viability by flow cytometry in all the ratios of live and dead spermatozoa, 1:0, 1:1 and 1:3 (p<0.01). The viability evaluated by ME were significantly correlated with that by flow cytometry in ratios of 1:0 and 1:3 (p<0.05) however, there was no significance in ratio of 1:1. The viability evaluated by C/p were highly correlated with that by flow cytometry in ratio of 1:0 and 1:1 (p<0.01) and significantly correlated in ratio of 1:3 (p<0.05). In frozen-thawed spermatozoa, the viability determined by HOS test was considerably correlated with that by flow cytometry (p<0.01). There was significant correlation between the viabilities by ME and by flow cytometry (p<0.05). But the viability evaluated by CFDA/PI was not correlated with viability by flow cytometry. The result from this study validate the use of flow cytometry as a precise method for assessing the viability of fresh and frozen-thawed dog spermatozoa.

• Journal of Chest Surgery
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• v.25 no.9
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• pp.900-904
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• 1992

Pulmonary blastoma is a very rare, primary, malignant neoplasm of the lung. The tumor typically is large, well-defined mass and arises in the periphery of the lung. Histologically, it resembles fetal lung tissue evoking the concept that these tumors are drived from the primitive pluripotential pulmonary blastema, but controversy also exit about the nature of this tumor. Clinical evaluation is inconsistant and unreliable as to the diagnostic determination of the tumor type and degree of malignancy. Therefore, diagnosis is usually based on histologic findings. The prognosis after adequate resection appears to be better than for other malignant tumors of the lungs. We experienced a case of pulmonary blastoma occurring in 56-year-old female. She was hospitalized for evaluation of an abnormal shadow in the left lower lung field which found incidentally on chest roentgenogram. We approached the lesion though left posterolateral thoracotomy and performed the left lower lobectomy. The microscopic findings of resected specimen revealed characteristic appearance of pulmonary blastoma. The postoperative course was uneventful without complication.

• Natural Product Sciences
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• v.13 no.2
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• pp.97-100
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• 2007

The present study includes macro and microscopical details, powder study, physico-chemical study and HPTLC fingerprinting of the Piper longum fruits. Microscopic studies revealed the presence of stone cells, starch grains and thin walled fragments of parenchymatous cells. Physico-chemical studies showed alcohol and ether soluble extract 24.53 and 6.7, sugar 0.35, starch 21.33 and tannin 0.83% respectively. Successive soxhlet extract showed maximum percentage of hexane soluble fraction i.e. 22.52. The HPTLC profile has also been performed against the reference marker pipeline, which was identified at R$_f$ 0.42. In the present paper a detailed pharmacognostical evaluation of fruit has been undertaken.