• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 추계종합학술대회 논문집(1)
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• pp.149-152
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• 2000

In this paper, the reverse link performance of an imperfect power controlled DS/CDMA cellular system that uses a base station array antenna which can effectively remove the multiple access interference is analyzed considering both beam forming algorithm and power control error in shadowing. The blocking probability of the DS/CDMA cellular system based on array parameters, Eb/No and statistics of interference is derived, and then the system capacity corresponding to a certain blocking probability is calculated. On the assumption that the blocking probability is set 1 ％, the system capacity using MCGM algorithm with 12 antenna arrays is increased about 59 % than that using 8 antenna arrays when power control error is 2.5 ㏈.

• 응용통계연구
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• 제22권1호
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• pp.59-73
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• 2009

A floating-strike lookback call option gives the holder the right to buy at the lowest price of the underlying asset. Similarly, a floating-strike lookback put option gives the holder the right to sell at the highest price. This paper will propose an outside floating-strike lookback call (or put) option that gives the holder the right to buy (or sell) one underlying asset at some percentage of the lowest (or highest) price of the other underlying asset. In addition, this paper will derive explicit pricing formulas for these outside floating-strike lookback options. Sections 3 and 4 assume that the underlying assets pay no dividends. In contrast, Section 5 will derive explicit pricing formulas for these options when their underlying assets pay dividends continuously at a rate proportional to their prices. Some numerical examples will be discussed.

• Journal of Trauma and Injury
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• 제30권2호
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• pp.47-50
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• 2017

A 21-year-old male visited our emergency room. He could not remember the mechanism of injury. He was found beside a motorcycle. Initial vital sign was stable. Observation and conservative treatment were planned at the intensive care unit (ICU). On the third day at ICU, he complained sudden flank pain. It was colicky and hard to control. Without the pain, he had no specific symptom, sign, or laboratory findings. On computed tomography, renal pelvis was filled with hematoma which induced hydronephrosis. Double-J catheter and percutaneous nephrostomy was implemented by an intervention radiologist. Hematome in the renal pelvis was aspirated during the procedure. Symptom of the patient was subsided after the procedure. He was discharged without specific complications.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2009년도 춘계학술발표회
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• pp.145-147
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• 2009

Nutrients in wastewater should be removed prior to release in the receiving waters to prevent the occurrence of eutrophication. In this study, seawater is used to remove ammonia and phosphate by the formation of struvite ($MgNH_{4}PO_{4}{\cdot}6H_{2}O$). It aims to know the optimum conditions for the removal of nutrients using seawater as source of magnesium ions. Experiments were performed using jar tester and pH of ammonium-phosphate solutions were adjusted Samples were drawn at different mixing times. It was shown that simultaneous removal of ammonia and phosphate is rapid, with no significant reduction beyond 10 min of mixing Another important parameter is pH, where range 10-11 showed the optimum nutrient removal. Increase in the volume of seawater, which meant an increase in magnesium ions also lead to better removal.

• 한국동물위생학회지
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• 제36권1호
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• pp.53-56
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• 2013

This study was carried out to investigate the seroprevalence of Neospora caninum infection in dairy cattle of northern Gyeonggi province in Korea. A total of 716 dairy cattle from 14 dairy farms were tested for the presence of antibodies against N. caninum using a commercial ELISA test kit. Herd and individual seroprevalences of N. caninum were 92.8% (13/14) and 23.1% (166/716), respectively. The seroprevalence of dairy cattle according to age was the highest at 49~72 months (27.4%), but the difference was not statistically significant (P>0.05). No significant relationship between N. caninum seropositivity with the herd size of the dairy farms was found (P>0.05). The results indicate that N. caninum infection spreads widely in dairy farms of northern Gyeonggi province in Korea.

• KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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• 제12B권1호
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• pp.37-43
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• 2002

This paper proposes a new zero-current switching (ZCS) pulse-width modulation (PWM) switch cell that has no additional conduction loss of the main switch. In this cell, the main switch and the auxiliary switch turn on and turn off under zero current condition. The diodes commutate softly and the reverse recovery problems are alleviated. The conduction loss and the current stress of the main switch are minimized, since the resonating current for the soft switching does not flow through the main switch. Based on the proposed ZCS PWM switch cell, a new family of dc to dc PWM converters is derived. The new family of ZCS PWM converters is suitable for the high power applications employing IGBTs. Among the new family of dc to dc PWM converters, a boost converter was taken as an example and has been analyzed. Design guidelines with a design example are described and verified by experimental results from the 2.5㎾ prototype boost converter operating at 40KHz.

• 응용통계연구
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• 제21권3호
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• pp.485-495
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• 2008

A floating-strike lookback call option gives the holder the right to buy at the lowest price of the underlying asset. Similarly, a floating-strike lookback put option gives the holder the right to sell at the highest price. This paper will present explicit pricing formulas for these floating-strike lookback options with flexible monitoring periods. The monitoring periods of these options start at an arbitrary date and end at another arbitrary date before maturity. Sections 3 and 4 assume that the underlying assets pay no dividends. In contrast, Section 5 will derive explicit pricing formulas for these options when their underlying asset pays dividends continuously at a rate proportional to its price.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.402-405
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• 2006

The diffuser noise of HVAC(heating ventilating and air-conditioning) uses dB(A) or NC as a indoor noise criteria that ASHRAE represents, and there is no specific guide line for application. According to the previous study, there are some problems like that even though the sound level of sound source is same, the NC shows different values, which makes the noise rating confused. This problem is caused by the frequency characteristics of sound source and its sound level. Therefore, appropriate evaluation method should be considered based on the subjective responses. This study aims to analyze the physical parameters appropriate for the evaluation of HVAC diffuser noise. To achieve this, recording of sound sources, calculation of physical parameters and psycho-acoustic experiment were carried out and the results were derived from the correlation analysis between physical parameters and subjective evaluatio

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2006년도 춘계학술대회논문집
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• pp.1317-1320
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• 2006

This study compared the floor impact sound level of rectangular receiving room type to differed receiving room types to analyze effect of room mode. The floor impact sound level of master room were higher than the level of living room which resulted from room mode. The result showed that the level of low frequency bandwidth in the location varied with receiving room types were lower than general measuring point of rectangular receiving room.

• 자원환경지질
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• 제16권4호
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• pp.253-256
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• 1983

Recently, excavation of ancient pottery kiln of Koryo celadon of the Koryo dynasty have been continued since 1979 in Hang-dong, Daegu-myun, Gangjin-gun, Jeonnam Province, south-western part of Korea. The authers carried out an archeomagnetic study using the baked earth of the floors of the kiln, togimi and fabrics of rocks which were placed firmly on the floors of the kiln. These specimens were measured using the astatic magnetometer. The results of measurements are: declination, $0.3^{\circ}W$; inclination, $52.9^{\circ}C$. Referring to the secular change curves drawn from the studies of the south-western Japan, the last period when the pottery kiln was fired finally is estimated to be around A.D. 1170. Many potsherds of Koryo celadon were excavated around the kiln. According to the shape of these potsherds, the age of the pottery kiln is estimated to be 10-12 C, which is consisted with this study.