• Journal of Chest Surgery
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• 제28권1호
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• pp.65-68
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• 1995

Pectus excavatum occasionally occurs in patients who have underlying cardiac disease, especially Marfan syndrome. This report describes a patient with pectus excavatum who had ascending aortic aneurysm with aortic regurgitation and anterior leaflet prolapse of mitral valve. This patient underwent replacement of aortic valve and ascending aorta with 25 mm SJM valved conduit graft[Bentall operation with Cabrol shunt , and mitral valve replacement with SJM 31 mm, the pectus excavatum was corrected at the time of completion of the intracardiac operation with the modified sternal turnover. This procedure offered excellent operative exposure for the inracardiac operation with prevention of low cardiac output after operation due to depressed sternum and maintained chest wall stability resulting good cosmetic chest wall appearance. This patient recovered and discharged in good postoperative result with minimal temporary peroneal nerve palsy in his left leg.

• Journal of Chest Surgery
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• 제30권3호
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• pp.263-269
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• 1997

From April 1987 to May 1996, 13 infants underwent a Norwood operation for complex congenital heart diseases including hypoplastic left heart syndrome (n : 7), mitral stenosis with small VSD and subaortic stenosis (n : 1), mitral atresia with ventricular septal defect, coarctation of aorta, and subaortic stenosis (n = 1), interrupted aortic arch with ventricular septal defect and subaortic stenosis (n : 1), tricuspid atresia with transposition of the great arteries (n = 1), and complex double-inlet left ventricle (n : 2). All patients without hypoplastic left heart syndrome were associated wit hypoplasia of ascending aorta and arch. Age at operation ranged from 3 days to 8.7 months (mean 60.6 $\pm$ 71.6 days, median 39 days). The operative mortality( < 30 days) was 46% (6 patients). Late mortality was 15% (2 patients). All operative deaths occured during the Erst 24 hours after the operation as a result of cardiopulmonary bypass weaning failure (5 patients) and sudden hemodynamic instability postoperatively (1 patient). Late death was due to aspiration pneumonia in two cases. There are 5 long-term survivals (39%). Three of them have undergone a two-stage repair with a modified Fontan operation in two and total cavopulmonary shunt in one at 12, 17, 4.5 months after Norwood procedure with no mortality. Two patients have entered a three-stage repair strategy by undergoing a bidirectional cavopulmonary shunt at 3 and 5.5 months after initial operation with 1 operative death. The actuarial survival rate for all patients at the first-stage operation, including hospital deaths and ate death was 30.8% at 1 year. In conclusion, the operative mortality of Norwood operation was relatively high compared to other operation for major cardiac anomalies, continuing experience will lead to an improvement in result.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제22권2호
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• pp.113-118
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• 2021

The guided weapon system should ensure economical operation and user safety. In particular, in the case of guided weapon systems developed in the form of a guaranteed bomb, the standards for maintaining reliability considering the long-term storage environment are presented during the development stage, and an optimized inspection cycle is required to maintain this. This study calculated the reliability through a trend test, fitness test, and distribution analysis using a mathematical model based on the maintenance status and shooting results during the inspection period for OO missiles currently in operation for a long time in the military. Through this, it was applied to the inspection period model (Martinez) set during the development stage to determine if the improved inspection period can be utilized. Finally, by synthesizing the data from these studies, a policy management plan was developed according to the extension of the inspection period. The One-Shot system was operated at the inspection period set when it was developed. The study analyzed the actual failure and maintenance data to reset the efficient inspection period.

• Journal of the Korean Society for Precision Engineering
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• 제14권8호
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• pp.57-64
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• 1997

The process design of backward and forward extrusion of axisymmetric part has been studied in this paper. The important factors of cold forging process with complex geometry are the design of initial billet shape, the possibility of forming by one-stage operation and the determination of preform shapes, etc. Based on the systematic procedure of process sequence design, the forming operation of cold forged part is analyzed by the commercial finite element program, DEFORM. The design criteria are forming load, geo- metrical filling without defect and a sound distribution of effective strain in final product. It is noted that one step of preform operation is required to obtain the final product. Numerical result is compared with experi- mental one. It is found that the analyzed result is in good agreement with actual forming result.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제20권4호
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• pp.35-42
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• 2019

Nut fasteners that require ultra-precise control are required in the overall manufacturing industry including electronic products that are currently developing with the automobile industry. Important performance factors when tightening nuts include loosening due to insufficient fastening force, breakage due to excessive fastening, Tightening torque and angle are required to maintain and improve the assembling quality and ensure the life of the product. Nut fasteners, which are now marketed under the name Nut Runner, require high torque and precision torque control, precision angle control, and high speed operation for increased production, and are required for sophisticated torque control dedicated to high output BLDC motors and nut fasteners. It is demanded to develop a high-precision torque control driver and a high-speed, low-speed, high-response precision speed control system, but it does not satisfy the high precision, high torque and high speed operation characteristics required by customers. Therefore, in this paper, we propose a control technique of BLDC motor variable speed control and nut runner based on vector control and torque control based on coordinate transformation of d axis and q axis that can realize low vibration and low noise even at accurate tightening torque and high speed rotation. The performance results were analyzed to confirm that the proposed control satisfies the nut runner performance. In addition, it is confirmed that the pattern is programmed by One-Stage operation clamping method and it is tightened to the target torque exactly after 10,000 [rpm] high speed operation. The problem of tightening torque detection by torque ripple is also solved by using disturbance observer Respectively.

• Proceedings of the IEEK Conference
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• 대한전자공학회 2005년도 추계종합학술대회
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• pp.711-714
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• 2005

We propose floating point arithmetic units for geometry operation of mobile 3D graphic processor. The proposed arithmetic units conform to the single precision format of IEEE standard 754-1985 that is a standard of floating point arithmetic. The rounding algorithm applies the nearest toward zero form. The proposed adder/subtraction unit and multiplier have one clock cycle latency, and the inversion unit has three clock cycle latency. We estimate the required numbers of arithmetic operation for Viewing transformation. The first stage of geometry operation is composed with translation, rotation and scaling operation. The translation operation requires three addition and the rotation operation needs three addition and six multiplication. The scaling operation requires three multiplication. The viewing transformation is performed in 15 clock cycles. If the adder and the multiplier have their own in/out ports, the viewing transformation can be done in 9 clock cycles. The error margin of proposed arithmetic units is smaller than $10^{-5}$ that is the request in the OpenGL standard. The proposed arithmetic units carry out operations in 100MHz clock frequency.

• Proceedings of the Korea Society for Simulation Conference
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• 한국시뮬레이션학회 1999년도 춘계학술대회 논문집
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• pp.184-188
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• 1999

The performance of an AGV varies with the applied AGV dispatching rule in the operation of AGVS. This study proposes a multi-attribute AGV dispatching rule. The suggested dispatching rule considers the output queue of a workstation, distance between an idle AGV and a workstation to be served, the input queue of the destination and the remaining job process of a part. This study suggests two types of and the remaining job process of a part. This study suggests two types of multi-attribute dispatching rules. One is an one-stage rule which selects the part to be served considering four attributes simultaneously. The other is a two-stage rule by which a workstation is selected and a part is chosen from the selected workstation. The simulation runs were executed under different experimental conditions to obtain preliminary statistics on the several performance measures.

• The Journal of Korean Medicine
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• 제17권2호
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• pp.100-116
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• 1996

Gastric cancer shows the most high friquency in cancers that occurs in Korea. The western medicine treatment for gastric cancer has radiation and surgery, chemical treatment. While, oriental medicine cures the gastric cancer by herb-drugs, acupunture , moxa and srigma. With just one way of treating gastric cancer can't be effective remedy. Because each medicine has a strength and weakness. Thus, it is effective treatment when two medicine combins and supplement each other. We got the following result about a trend of oriental and westernal combination treatment for gastric cancer through studing records. 1. The western medicine treats gastric cancer patient with surgery first and right after surgery. They need on assembly treatent such as chemical and immune treatment. In oriental medicine, they treats gastric cancer patients with differentiation of symptone and signs and treatment(辨證施治)[for example:incoordination between liver and stomach(肝胃不和), insufficiency of spleen and stomach(脾胃虛弱), stagnation of blood stasis and toxic agent(瘀毒內阻), deficiency of yin by stomach heat(胃熱傷陰), reinforcing both qi and blood(氣血雙虧), stagnation of damp-phlegm(痰濕凝結)] and cure for them by acupuncture and stigma, too. 2. In combination with oriental and western medical treatment principle of gastric cancer by each stage is as follows. First stage and second stage gastric cancer is cured with radical surgery mainly. After operation, the herb of invigoration of the spleen(健脾), coordination of the stomach(和胃), and smoothing the liver and regurating the circulation of qi(疏肝理氣), is used for good gastroenteric condition. The second stage patients can be concidered using in combination with chimical treatment. The third stage gastric cancer is treated with radical surgery or with temporizing surgery. After those surgery, herb-drugs treatment is used jointly. The fourth stage patients who have no extensively metastasis or local contraindication can undergo temporizing and curcuit surgical operation. Herb-drugs and chemical treatments are used together for patients after operating. If he has operating contraindication, he would be treated with herb-drugs and chemical treatment. 3. In case of using in combination with oriental and western medical treatment as follows. As for herb-drugs with chemical treatment, reinforcing both qi and blood(補益氣血), invigorate the spleen and the stomach(健脾和胃), reinforcing liver and kidney(滋補脾腎), clear out the heat and relieve the toxic agent(淸熱解毒), can be used and with radiation treatment, clear out the heat and relieve the toxic agent(淸熱解毒), promoting the production body fluid and moisturizing the vicera(生津潤燥), reinforcing both qi and blood(補益氣血), invigorate the spleen and the stomach (健脾和胃), reinforcing liver and kidney(滋補肝腎) etc, can be used. 4. According to the research of oriental and western medical combination treatment are the 5-year-survival degree with oriental and western medicine combination treatment was for better than that just with oriental or western medical treatment. Especially, it has good effect on the third, fourth stage gastric cancer. That is, the middle and the end of stage gastric cancer. 5. The merits of oriental and western medicine combination treatment are lengthers one's life and diminish the bad effect of chemical treatment and radiation treatment be near completion, prevent from relapsing, maintain the balance in their eveirenment of body and improve immunity.

• Journal of Korean Society on Water Environment
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• 제36권6호
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• pp.546-558
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• 2020

While industrialization has provided in abundance, the pollution it creates has caused untold damage to the environment, increasing the frequency and severity of natural disasters through changes in global climate patterns. The World Risk Forum's (WEF) World Risk Report presented the results of a survey of experts from around the world detailing the most influential risk factors over the next decade. Notably, the failure to respond to climate change ranked first and the global water crisis third. The extreme drought in the western Chungnam province was unexpected in 2016. At the time, the water level of Boryeong Dam was drastically decreased due to receiving less than half the average recorded rainfall in the region that year. The Boryeong Dam diversion pipeline has the capacity to solve the water shortage problem between these two regions by providing water from Geumgang to the western part of Chungnam, including Boryeong City. Current weather trends suggest drought is likely to continue in western Chungnam, which uses the Boryeong Dam as an intake source. This makes it necessary to operate Boryeong Dam diversion pipeline in an efficient and effective manner. SWAT is a watershed scale model developed to predict the impact of land management practices on water. The SWAT model was used in this study to evaluate the adequacy of the Boryeong Dam diversion pipeline operational plan by comparing it to present Boryeong Dam diversion pipeline operation. By investigating the number of days required to reach each reservoir stage, we determined that the number of days required to reach the boundary stage was less than that of the current operation. This determination accounts for the caveats that the Boryeong Dam waterway was not operated and only one pump will be operated from October to May of next year. As our results suggest, the most stable operation scenario is to operate two pumps at all times. This can be accomplished by operating two pumps from the caution stage to increase the number of pumps whenever the stage is raised. In addition to the stable operation of the Boryeong Dam pipeline, policy considerations are required with regard to imposing a water use charge on users of the Boryeong Dam region.

• Journal of the Korea Institute of Information and Communication Engineering
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• 제16권10호
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• pp.2253-2260
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• 2012

In this paper, an efficient hardware architecture is proposed for inverse transform and inverse quantization of H.264/AVC decoder. The previous inverse transform and quantization architecture has a different AC and DC coefficients decoding order. In the proposed architecture, IQ is achieved after IT regardless of the DC or AC coefficients. A common operation unit is also proposed to reduce the computational complexity of inverse quantization. Since division operation is included in the previous architecture, it will generate errors if the processing order is changed. In order to solve the problem, the division operation is achieved after IT to prevent errors in the proposed architecture. The architecture is implemented with 3-stage pipeline and a parallel vertical and horizontal IDCT is also implemented to reduce the operation cycle. As a result of analyzing the proposed ITIQ architecture operation cycle for one macroblock, the proposed one has improved by 45% than the previous one.