• The Journal of Information Technology
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• v.5 no.2
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• pp.69-80
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• 2002

Conventionally, we have used an acoustic microscope at single operating frequency. The resolution and quality of the measured images are determined by transducer of the microscope. In this paper, we have studied Vertical Resolution Enhancement with Acoustic Reflection Microscope using combining bases of support for SFR(Spatial Frequency Response). Increased Vertical resolution can be obtained by taking three-dimensional images at more that one frequency and numerically combining the results. As results of the experiment, we could get enhanced images with the rate of contrast in proportion to the changing rate of depth.

• Journal of Power Electronics
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• v.4 no.2
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• pp.87-95
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• 2004

A new fast-response high-current clamp DC-DC converter circuit design is presented that will meet the requirements and features of the new generation of microprocessors and digital systems. The clamp in the proposed converter amplifies the current in case of severe load changes and is able to produce high slew rate of output current and capability to keep constant the output voltage. This proposed high-current clamp technique is theoretically loss less, low cost and easy to implement with simple control scheme. This is modified from a basic buck topology by replacing the output inductor with two magnetically coupled inductors. Inductors are difference in inductance, one has large inductance and other has small inductance. The inductor with small inductance will take over the output inductor during fast load transient. It speedup the output current slew rate and reduce the output voltage drop in the case of heavy burden load changes.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.20 no.10
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• pp.9-18
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• 2021

The cutting force in a cutting simulation is determined by the cutting conditions, such as cutting speed, feed rate, and depth of cut. The cutting force changes, depending on the material and cutting conditions, and is affected by the heat generated during cutting. The physical properties for predicting the cutting force use constitutive equations as functions of the hardening term, rate-hardening term, and thermal-softening term. To accurately predict the thermal properties, it is necessary to accurately predict the thermal-softening coefficient. In this study, the thermal-softening coefficient was determined, and the cutting force was predicted, using the response-surface method with the cutting conditions and the thermal-softening coefficient as factors.

• Journal of Yeungnam Medical Science
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• v.38 no.4
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• pp.308-317
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• 2021

Cancer is the leading cause of death and is on the rise worldwide. Until 2010, the development of targeted treatment was mainly focused on the growth mechanisms of cancer. Since then, drugs with mechanisms related to tumor immunity, especially immune checkpoint inhibitors, have proven effective, and most pharmaceutical companies are striving to develop related drugs. Programmed cell death-1 and programmed cell death ligand-1 inhibitors have shown great success in various cancer types. They showed durable and sustainable responses and were approved by the U.S. Food and Drug Administration. However, the response to inhibitors showed low percentages of cancer patients; 15% to 20%. Therefore, combination strategies with immunotherapy and conventional treatments were used to overcome the low response rate. Studies on combination therapy have typically reported improvements in the response rate and efficacy in several cancers, including non-small cell lung cancer, small cell lung cancer, breast cancer, and urogenital cancers. The combination of chemotherapy or targeted agents with immunotherapy is one of the leading pathways for cancer treatment.

• Journal of agricultural medicine and community health
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• v.43 no.3
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• pp.172-179
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• 2018

Objectives: To review the status of newborn hearing screening (NHS) and to investigate the effect of the examiners on NHS tests to help the quality control of NHS at a general hospital in a city. Methods: The charts of newborns from January 2015 to March 2016 and from August 2016 to October 2017 were retrospectively reviewed. We compared the results of tests performed by several examiners(group 1) with those performed by one audiologist (group 2) using the same automated auditory brainstem response test. Results: The screening rate and referral rate were not significantly different between group 1 and group 2. The confirmatory test rate was higher in the group 2, but it was not significant. In group 1, the number of tests performed 3 or more times in one ear at one time was significantly higher. The number of tests performed in only one ear at one time was higher in group 2. The screening rate within one month after birth was 64.21%, referral rate was 7.32%, confirmatory test rate within 3 months after birth was 21.74%, and the prevalence of hearing loss was 1.46%. Conclusions: There was no significant difference of results depending on the examiners. In order to make proper screening test, it is necessary to periodically educate the examiner and to instruct the examiner by the supervisor doctors.

• Journal of Korean Physical Therapy Science
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• v.23 no.1
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• pp.1-8
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• 2016

Purpose : The purpose of this study was to investigate the response of pulmonary function and heart rate recovery of smoker and nonsmoker in males aged 20s after graded maximal exercise. Method : The subjects were composed of smoker group (n=12) and nonsmoker group (n=12) in males aged 20s. Each groups completed an graded maximal exercise with Bruce protocol and were assessed on the pulmonary function(forced vital capacity : FVC, forced expiratory volume-one second : FEV1, FEV1/FVC) and heart rate. Result : The results were as follows: First, heart rate in the measurement point was a statistically significant difference for smoker and non-smoker group after maximal exercise, but FVC, FEV1, FEV1/FVC was no difference. Second, FEV1/FVC between smoker and nonsmoker group was a statistically significant difference after maximal exercise, but FVC, FEV1, heart rate was no difference. Conclusion : The results of this study is that smoking is negative effects on FEV1/FVC of pulmonary function in males aged 20s after maximal exercise.

• Journal of Chest Surgery
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• v.29 no.5
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• pp.536-541
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• 1996

Between June 1988 and June 1994, twenty five patients with locAlly advanced esophageal carcinoma received preoperative chemotherapy (Cisplatln, 5-Fluorouracil with or without Etoposide) and followed by resection. All patients had clinical evidence of airway involvement or distant Iymphnode involve- ment (M 1 Iymphnode) on bronchoscopy or computed tomographic scans. The major response rate to chemotherapy decided by the postoperative stage was 48% (12125). The resection rate was 92% (23/25) with overall complete resection rate of 72% (18125). Two patients had exploratory laparotomy (thorn- cotomy) only. Thirteen patients had esophagogastrostomy with a combined abdominl and Rt. thoracic approach (Ivor Lewis operation), slx pAtients had transhiatal esophagectomy, four patients had esophagogastrostomy with a combined Rt. thoracotonly & abdominal, cervical approach. There were three postoperative deaths (12%). Follow-up duration was between 3.3 months to 65 months. Median survival ime of resected patients except hospital death was 14.8 months. Actuarial survival at 12, 24 months was 72.9%, 26.2%. Signifi- cant better survival was associated with responder group (postoperative stage less than lIB) (P=0.029). These results demonstrate that 1) Preoperative Cisplatin based combined chemotherapy Produce high response rate, 2) High complete resection rate with acceptable mortality rate occur after preoperative chemotherapy, 3) Better surviL dl can be anticipated if complete resection performed after major re- sponse to preoperative chemotherapy.

• Journal of the Korean Chemical Society
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• v.57 no.6
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• pp.769-777
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• 2013

The effect of operating conditions (temperature and the partial pressures of H2 and CO) on the reaction rate of Fischer-Tropsch synthesis (FTS) were investigated by carrying out experiments according to a Box-Behnken design (BBD), and were mathematically modeled by using response surface methodology (RSM). The catalyst used was a nano-structured cobalt/manganese oxide catalyst, which was prepared by thermal decomposition. The rate of synthesis was measured in a fixed-bed micro reactor with $H_2/CO$ molar feed ratio of 0.32-3.11 and reactor pressure in the range of 3-9.33 bar at space velocity of $3600h^{-1}$ and a temperature range of 463.15-503.15 K, under differential conditions (CO conversion below 2%). The results indicated that in the present experimental setup, the temperature and the partial pressure of CO were the most significant variables affecting reaction rate. Based on statistical analysis the quadratic model of reaction rate of FTS was highly significant as p-value 0.0002.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.11
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• pp.1964-1970
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• 2010

A new intelligent power network (Smart Grid) that grafts some new technologies, such as the extension of the new and reproducible energy, electric motors, and electric storages, onto the regulation of green house gases according to the recent convention on climate changes has been actively promoted. As establishing such an intelligent power network, it is possible to implement a real-time rate system according to the change from the conventional single directional information transmission to the bidirectional information transmission. Such a real-time rate system can provide power during the chip rate hour by avoiding the high rate hour although customers use the same level of power through providing such real-time rate information including power generation costs. In this study, the establishment of an operating system that makes an effective use of the real-time rate system and its operation method are to be proposed.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.13 no.5
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• pp.334-340
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• 2003

Exponential window function Is widely used In impact hammer testing to reduce leakage error as well as to get a good S/N ratio. The larger its decaying rate is, the more effectively the leakage errors are reduced. But if the decay rate of the exponential window is too large, the FRF is distorted. And the modal parameters of the system can not be exactly identified by modal analysis technique. Therefore, it is a difficult problem to determine proper decay rate in impact hammer testing. In this paper, amount of the FRF distortion caused by exponential window is theoretically uncovered. A new circle fitting method is also proposed so that the modal parameters are directly extracted from impulse response spectrum distorted by the exponential-windowed impulse response data. The results by the conventional and proposed circle fitting method are compared through a numerical example.