• Current Optics and Photonics
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• v.6 no.4
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• pp.400-406
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• 2022

We numerically demonstrate that the inherent spiking behavior in the quasi-continuous-wave (QCW) operation of an Nd:YAG laser can be suppressed by adopting bias pumping. After spiking suppression, the output QCW pulses from a bias-pumped Nd:YAG laser are very stable, and they can maintain nearly the same temporal shape as that of pump pulse under different pump repetition rates and peak powers. Our study implies that bias pumping is an alternative method of spiking suppression in solid-state lasers, and the application areas of an Nd:YAG laser may be extended by bias pumping.

• 한국신재생에너지학회:학술대회논문집
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• 2010.06a
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• pp.198.2-198.2
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• 2010

In this study, the COP variation with the duration of Ground Source Heat Pump (GSHP) systems operation was analyzed by experiment. This experimental facility was installed in residential house as a back-up device of solar thermal heating system. The capacity of heat pump is 2.5 kW with a vertical bore hole of 150m depth. The COP of GSHP is varied, depending on the ground temperature which is used as a heat source. The ground heat source temperature influencing heating COP is the soil or rock temperature which adjoin with geo-source heat exchanger. This temperature is decreased rapidly according to the operation duration of heat pump. As a result, COP of GSHP is decreased to 3 in one hour of continuous operation time.

• Journal of Chest Surgery
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• v.13 no.2
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• pp.130-133
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• 1980

Since the first report of an operation for prolapsed intervertebral disk by Mixter and Barr[1934], many thousands of operations have been successfully performed without incident. Linton and White in 1945 reported the vascular complication, but perforation of large vessels is rare complication of operation for prolapsed disk. A medical student, aged 22 years, was performed to a disk operation [L4-5, Rt. on May 1977.] From postoperative 10th day, palpitation, generalized edema and substernal pain were noted, and 2 months later, wide pulse pressure [70-80 mmHg], continuous bruit and thrill on the Rt. low abdomen were followed. Aortography revealed arteriovenous fistula between just proximal to abdominal aortic bifurcation and inferior vena cava. So, fistulectomy [Resection of proximal 2 cm of C.I.A., Rt, including fistula opening and end to end anastomosis] was performed on July, 77. During follow up study, remained fistula between Rt. internal lilac artery and lilac vein was found 2 months later. Re-operation [Double ligation of the Rt. internal lilac artery] was don on January 1978. Postop. results were excellent, except impossible to ejaculation.

• Journal of Chest Surgery
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• v.39 no.1 s.258
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• pp.48-55
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• 2006

Background: The benefits of preoperative use of aspirin and plavix in coronary patients have been well documented. Due to their bleeding tendency, there have been many discussions about when to stop the antiplatelet agent before operation. We evaluated the effects of preoperative continuous use of aspirin and plavix in OPCAB patients. Material and Method: 123 patients underwent OPCAB from March, 2004 to Feb., 2005. We divided them into two groups; those who had continuous administration of aspirin and plavix during the preoperative period (n=45, 36.6$\%$) and those who discontinued them at least one day before the operation (n=78, 63.4$\%$). We then compared the platelet count, hemoglobin/hematocrit level, graft patency, postoperative bleeding and related complications, and operation time between the two groups. The patients were also divided into long-term users ($\geq$ 1 month) and short-term users (< 1 month), with the aforementioned factors equally compared. Result: There was no statistical difference between the two groups regarding postoperative bleeding, related complications, graft patency, operation time and mortality. Continuous users showed significantly low platelet levels on immediate post operation (p=0.02), postoperative day (POD) $\sharp$1 (p=0.002) and POD $\sharp$2 (p=0.021), respectively. But there was no difference on POD $\sharp$7. Long-term users showed statistically significant difference in pre- and postoperative platelet count, but none in postoperative bleeding and related complications. Conclusion: Continuous use of aspirin and plavix did not increase postoperative bleeding or related complications. Also graft patency and mortality had no statistical differences in continuous users. We think that there is no need to stop aspirin and plavix before OPCAB.

• Journal of Chest Surgery
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• v.31 no.4
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• pp.353-361
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• 1998

Hypothermia is widely acknowledged as fundamental component of myocardial protection during cardiac operations. Although it prolongs the period of ischemic arrest by reducing oxygen demands, hypothermia is associated with a number of major disadvantages, including its detrimental effects on enzymatic function, energy generation, and cellular integrity. The ideal way to rotect the heart is to electromechanically arrest it and perfus it with blood that is aerobic arrest. However alternative technique has been developed, based on the principles of electromechanical arrest and normothermic aerobic perfusion using continuous warm blood cardioplegia. To determine if continuous warm blood cardioplegia was beneficial in clinical practice during valvular surgery, we studied two groups of patients matched by numbers and clinical characteristics. Group included is 31 patients undergoing valvular surgery who received intermittent cold crystalloid cardioplegia. Group II included 30 patients undergoing valvular surgery who received continuous warm blood cardioplegia. Our results suggest that the heartbeat in 100% of patients treated with continuous warm blood cardioplegia converted to normal sinus rhythm spontaneously after the removal of the aortic cross-clamp, compared to only 31% of the cold cardioplegia group. After operation, pericardial closure rate was 90% area in the warm group, compared to 35% area in the cold group. 12 hours after the operation, the total amount of urine output in the warm group was greater than that in the cold group(2863${\pm}$127 ml versus 2257${\pm}$127 ml; p<0.05). After the operation, left diaphragmatic elevation developed in 55% of the cold group but in 0% of the warm group. CK-MB level in the warm group was significantly lower than cold group(2.28${\pm}$0.62 versus 9.96${\pm}$2.12; p<0.01) 1 hour after operation and CK-MB level in the warm group was significantly lower than cold group(1.80${\pm}$1.01 versus 6.00${\pm}$1.74; p<0.05) 12hours after operation. Continuous warm blood cardioplegia is at least as safe and effective as hypothermic technique in patients undergoing cardiac valvular surgery. Conceptually, this represents a new approach to the problem of maintaining myocardial preservation during cardiac operations.

• Korean Journal of Remote Sensing
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• v.36 no.5_4
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• pp.1167-1177
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• 2020

In this study, we established the process for collecting and utilizing video scripts of disaster site based on public-private partnerships. It is for the purpose of actively utilizing private capabilities in disaster management, and quickly sharing video scripts to identify field conditions. Based on the experience of actual operation of public-private partnerships system in the event of typhoon in 2019, we also derived implications for continuous operation of the process. Results are meaningful in that the government established the process for collecting and utilizing video scripts through public-private partnerships during the initial disaster response phase. And we also confirmed the possibility of spreading positive perception of disaster management organizations. However, there is a limit to the actualization and practical use of performance as an experimental pilot operation in the R&D stage. In addition, for continuous operation of the system, it is necessary to prepare institutional support measures such as organization, infrastructure for operating, programs of education and training, and policy making.

• The Korean Journal of Pain
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• v.9 no.1
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• pp.135-139
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• 1996

Intercostal nerve blockade with local anesthetics has been used extensively in the past to provide pain relief following thoracotomy. Its popularity fell, for a period, probably due to increasing use of epidural analgesia. More recently, interest has focused on intercostal nerve block with the introduction of variously sited catheters. Two epidural catheters were placed under direct vision, in the intercostal spaces just above and below the wound by feeding the catheters posteriorly from the wound edges, superficial to the parietal pleura. Bupivacaine 0.25%. Was infused continuously at a rate of 5 ml/hour through each of the two intercostal catheters. Each catheter was primed with 10 ml/hour through each of the two intercostal catheters. Each catheter was primed with 10 ml of 0.25% bupivacaine. Postoperative vital signs resembled preoperation data. Arterial carbon dioxide pressure ($PaCO_2$) was unchanged and arterial oxygen pressure ($PaO_2$) was increased during two days after surgery because oxygen was administered at 21/min. Forced vital capacities (FVC) and forced expiratory volume in 1 second ($FEV_1$) were decreased the day of operation but restored to preoperative value from second operation day. VAS were increased on operation day but decreased from second operation day. Motion range of arms were not impaired. We concluded that continuous intercostal nerve block through catheters placed during thoracotomy in the adjacent intercostal spaces is a simple and effective method for management of the post-thoracotomy pain.

• Journal of the Korea Society for Simulation
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• v.20 no.2
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• pp.49-57
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• 2011

Stiff competition and skyrocketing prices of raw materials are increasingly demanding the optimal design and operation of iron and steel mills minimizing trial and error. Computer simulation can provide the methodology in accordance with requirements. The purpose of this paper is to suggest a simulator for the design and operation of the steelmaking and continuous casting mill. The simulator was developed using Arena, popular simulation software and input and output interface based on MS Excel. It allows easy access for the maintenance and extension of the model. One of distinct features of the proposed simulator is the inclusion of complex transportation modules composed of transfer cars and overhead cranes. The simulator can be used for evaluating various alternative designs of a projected mill via throughput analysis and material flow analysis. Also, one can utilize it effectively to search for the best product mix suitable for many types of situations. It could be an invaluable tool evaluating the performance of operation patterns and improving the accuracy.

• Proceedings of the KIEE Conference
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• 1990.11a
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• pp.218-219
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• 1990

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1997.12a
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• pp.227-232
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• 1997