• Asian Pacific Journal of Cancer Prevention
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• v.16 no.8
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• pp.3223-3227
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• 2015

Objective: We evaluated the association of body mass index (BMI) with perioperative outcomes in patients who underwent laparoscopic or open radical nephroureterectomy. Materials and Methods: This retrospective single-center study included 113 patients who had been diagnosed with upper urinary tract cancer from January 1998 to June 2013 and were treated with laparoscopic nephroureterectomy (Lap group, n=60) or open nephroureterectomy (Open group, n=53). Laparoscopic nephroureterectomy was performed via a retroperitoneal approach following an open partial cystectomy. The two surgical groups were stratified into a normal-BMI group (<25) and a high-BMI group ($BMI{\geq}25$). The high-BMI group included 27 patients: 13 in the Lap group and 14 in the Open group. Results: Estimated blood loss (EBL) in the Lap group was much lower than that in the Open group irrespective of BMI (p<0.01). Operative time was significantly prolonged in normal-BMI patients in the Lap group compared to those in the Open group (p=0.03), but there was no difference in operative time between the Open and Lap groups among the high-BMI patients. Multivariate logistic regression analysis of the data for all the cohorts revealed that the open procedure was a significant risk factor for high EBL (p<0.0001, hazard ratio 8.02). Normal BMI was an independent predictor for low EBL (p=0.01, hazard ratio 0.25). There was no significant risk factor for operative time in multivariate analysis. There were no differences in blood transfusion rates or adverse event rates between the two surgical groups. Conclusions: Laparoscopic radical nephroureterectomy via a retroperitoneal approach can be safely performed with significantly reduced EBL even in obese patients with upper urinary tract cancer.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.6
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• pp.1010-1017
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• 2013

Two-axial electrodynamic forces generated on a conductive plate by a partially shielded magnet wheel are strongly coupled through the rotational speed of the wheel. To control the spatial position of the plate using magnet wheels, the forces should be handled independently. Thus, three methods are proposed in this paper. First, considering that a relative ratio between two forces is independent of the length of the air-gap from the top of the wheel, it is possible to indirectly control the in-plane position of the plate using only the normal forces. In doing so, the control inputs for in-plane motion are converted into the target positions for out-of-plane motion. Second, the tangential direction of the open area of the shield plate and the rotational speed of the wheel become the new control variables. Third, the absolute magnitude of the open area is varied, instead of rotating the open area. The forces are determined simply by using a linear controller, and the relative ratio between the forces creates a unique wheel speed. The above methods were verified experimentally.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.431-434
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• 2009

Conceptual study of an open-circuit type low-speed wind tunnel for test of wind turbine blade is conducted. The tunnel is constituted of a settling chamber, a contraction, closed and open test sections, a diffuser, two corners, a cross leg and a fan and motor. For the performance test, the closed test section width of 1.8 m, height of 1.8 m and length of 5.25 m is selected. The open test section with dimension width of 1.8 m, height of 1.8 m and length of 4.14 m is adopted for aeroacoustic test. The contraction ratio is 9 to 1 and maximum speed in the closed test section is 67 m/sec. Input power in the tunnel is about 238 kW and its energy ratio is 3.6. The wind tunnel designed in present study will be an effective tool in research and development of wind turbine.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.2
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• pp.245-251
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• 2011

In this paper, dual-band bandpass filter by using Pseudo-Interdigital Stepped-Impedance Resonator(PI-SIR) and Open-Loop Ring Resonator(OLRR) is proposed. The first passband and second passband are formed by PI-SIR and the second passband is reinforced by an OLRR. In a PI-SIR the first band and second band are easily and exactly adjusted by characteristic impedance ratio and electrical length ratio. The proposed design method may be confirmed to be useful from fabricated and measured results for dual-band bandpass filter operated at 2.45 GHz and 5.8 GHz.

• Biomolecules & Therapeutics
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• v.9 no.2
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• pp.125-130
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• 2001

Shin-Ki-Hwan (Shen-Qi-Wan, SKH), Bo-Jung-Ik-Ki-Tang (Bu-Zhong-Yi-Qi-Tang, BJIKT), and Sa-Mul-Tang (Si-Wu-Tang, SMT) have been used for various kinds of deficiency syndromes, such as 'yang', 'qi', and 'blood', respectively. The objects of this study were to determine the effects of water extracts of three different kinds of traditional Chinese medicine (TCM), SKH, BJIKT, and SMT, on the anxiolytic activities in the elevated plus-maze test and to clarify the differences among 'yang', 'qi', and 'blood'. The water extracts of SKH, BJIKT, and SMT were orally administered to male SD rats, at 1.0 g/kg for 10 days. All rats were subjected to behavioral tests for the anxiolytic activity at 10 days. SKH, for the benefiting 'yang'agents, significantly increased the ratio of open arms entry to the total arms entry and time spent in the open arms (p<0.05), suggesting anxiolytic effect. However, both BJIKT and SMT decreased the ratio of open arms entry to the total arms entry and increased times spent in the closed arms (p<0.05). From these findings, it can be speculated that SKH only exhibits anxiolytic effect and that the different anxiolytic effects in the elevated plus-maze test may be come from the meanings of 'yang', 'qi', and 'blood'in oriental diagnostics though the cases are restricted.

• Structural Engineering and Mechanics
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• v.76 no.3
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• pp.421-433
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• 2020

Masonry infills are normally considered as non-structural elements in design practice, therefore, the interaction between the bounding frame and the strength contribution of masonry infills is commonly ignored in the seismic analysis work of the RC frames. However, a number of typical RC frames with irregular distributed masonry infills have suffered from undesirable weak-story failure in major earthquakes, which indicates that ignoring the influence of masonry infills may cause great seismic collapse risk of RC frames. This paper presented the investigation on the risk of seismic collapse of RC frames with irregularly distributed masonry infills through a large number of nonlinear time history analyses (NTHAs). Based on the results of NTHAs, seismic fragility curves were developed for RC frames with various distribution patterns of masonry infills. It was found that the existence of masonry infills generally reduces the collapse risk of the RC frames under both frequent happened and very strong earthquakes, however, the severe irregular distribution of masonry infills, such as open ground story scenario, results in great risk of forming a weak story failure. The strong-column weak-beam (SCWB) ratio has been widely adopted in major seismic design codes to control the potential of weak story failures, where a SCWB ratio value about 1.2 is generally accepted as the lower limit. In this study, the effect of SCWB ratio on inter-story drift distribution was also parametrically investigated. It showed that improving the SCWB ratio of the RC frames with irregularly distributed masonry infills can reduce inter-story drift concentration index under earthquakes, therefore, prevent weak story failures. To achieve the same drift concentration index limit of the bare RC frame with SCWB ratio of about 1.2, which is specified in ACI318-14, the SCWB ratio of masonry-infilled RC frames should be no less than 1.5. For the open ground story scenario, this value can be as high as 1.8.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1987.10a
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• pp.35-35
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• 1987

Consider a job shop that is modelled as an open queueing network of the Jackson(l957) type. All work stations in the shop have the same number of parallel servers. Two problems are studied : the loading of stations and the assignment of servers, which are represented by loading and assingment vectors, respectively. Ma jorization and arrangement orderings are established to order, respectively, the loading and the assignment vectors. It is shown that reducing the loading vector under ma jorizat ion or increasing the assignment vector under arrangement ordering will reduce the congestion in the shop in terms of reducing the total number of jobs(in the sense of likelihood ratio ordering), the maximum queue length(in the sense of stochastic ordering), and the queue-length vector( in the sense of stochastic majorization). The results can be used to supprot production planning in certain job shops, and to aid the desing of storage capacity. (OPEN QUEUEING NETWORK; WJORIZATION; ARRANGEMENT ORDERINC; LIKELIHOOD RATIO ORDERINC; STOCHASTIC ORDERING)

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1513-1516
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• 2003

A crank throw, which is one of the crankshaft part for a large diesel engine is manufactured by closed die forging or open die forging. For the purpose of improvement of productivity the open die forging is usually adopted these days. However it has disadvantage of low yield ratio compare to closed die forging. To overcome this problem, the material properties for hot top and bottom zones of ingot are investigated to utilize them to the product and a modified forging process to reduce the material loss of ingot body through forging analysis according to forging factors(a , R, Ø$\sub$B/, Ø$\sub$D/) is suggested.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.5
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• pp.39-51
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• 2014

This paper deals with design of a direct-coupled, small-scaled permanent magnet generator (PMG) for wind power application. First, this paper determines rated power and speed of the PMG from measured characteristics of wind turbines. Second, we derive analytical solutions for the open-circuit field in order to determine optimum magnet thickness and pole pitch/arc ratio. Third, on the basis of open circuit field solutions, stator magnetic circuit including slot opening, teeth width and yoke thickness is designed. And then, a diameter of stator coil which agree with a required current density is calculated, and its turns are determined from the area of slot considering winding packing factor. Finally, finite element (FE) method is employed in analyzing the details of the designed PMG and, test results such as back-emf measurements are given to confirm the design.

• Proceedings of the Optical Society of Korea Conference
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• 2004.02a
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• pp.296-297
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• 2004

A Signal processor for the open-loop fiber optic gyroscope(FOG) is equipped with a stabilizer to reduce the error due to drift of fiber phase modulator (FPM). The stabilizer is designed to be operated to maintain the ratio of amplitude and phase between harmonics in the FOG signal. When FPM stabilizer is used, the temperature drift of FOG is reduced to less than 0.5 deg/hr in change of 20$^{\circ}C$.