• 수산경영론집
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• 제48권2호
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• pp.33-51
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• 2017

The purpose of this study is to estimate conservation value of fisheries resource protected area by the double-bounded dichotomous choice contingent valuation method. The data in this analysis come from a survey of respondents of resident in fisheries resource protected area using a proportional stratified sampling from the population. The questionnaires covered all the 5 fisheries resource protected area and the sample size of every protected area was 120 questionnaires. The survey period was from August to October in 2016. Above all, the average willingness to pay amount(WTP) per person of Namhae-Tongyoung I, Namhae-Tongyoung II, Jindong bay, Hansan bay, Cheonsu bay is estimated \6,215, \13,215, \6,405, \9,785, and \10,390 respectively. And, the total value of Namhae-Tongyoung I, Namhae-Tongyoung II, Jindong bay, Hansan bay, and Cheonsu bay is evaluated \108.8 billion, \357 billion, \118 billion, 210.2 billion, \ 245.8 billion respectively. Moreover, the yearly value of Namhae-Tongyoung I, Namhae-Tongyoung II, Jindong bay, Hansan bay, and Cheonsu bay is evaluated \6 billion, \19.6 billion, \6.5 billion, 11.6 billion, \ 13.5 billion. In conclusion, fisheries resource protected area has the higher conservational value. Consequently, it is essential for now or future generation's use of fisheries resources. In light of the fisheries resource protected area's value and importance, this should be promoted to the public including the local community who utilizes fisheries resource protected area wisely. Also, this suggests that the policy for fishery resource's creation and management is needed in fisheries resource protected area.

• 대한전자공학회논문지TC
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• 제42권11호
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• pp.61-66
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• 2005

본 논문은 WLAN에 이용되는 상위 6비트 온도계 코드의 전류원 셀 매트릭스와 중간 2비트 온도계 코드의 전류원, 그리고 하위 2비트 이진 가중치 코드의 서브 블록으로 구성된 10비트 210MHz의 CMOS 전류구동 디지털-아날로그 데이터 변환기(DAC)을 설계하였다. 제안된 새로운 글리치 억제회로는 입력된 신호의 교차되는 위치를 조절함으로써, 글리치 에너지를 최소화하도록 설계하였다. 또한 제안된 10비트 DAC는 CMOS $0.35{\mu}m$ 2-poly 4-metal 공정을 이용하여 설계하였으며, 유효 칩 면적은 5mm2이다. 제안된 10비트 DAC 칩의 측정결과, 변환속도는 210MHz, DNL/INL은 각각 ${\pm}0.7LSB/{\pm}1.1LSB$이며, 글리치 에너지는 $76pV{\cdot}sec$이고, SNR은 50dB, SFDR은 53dB((a)200MHz), 전력소비는 83mW((a)3.3V)로 측정되었다.

• 전자공학회논문지SC
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• 제44권1호
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• pp.1-11
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• 2007

본 논문에서는 UPS 인버터의 성능 개선을 위하여 출력측 LC 필터의 커패시터 전압과 전류의 2중 제어루프를 구성하고, 2중 제어루프에 디지털 제어시스템을 설계하였다. 또한, 디지털 제어기의 연산지연시간을 보상하기 위하여 이러한 연산지연시간을 인버터 플랜트의 고유한 파라미터로 가정하고, 플랜트 모델에 포함시켜 모델링 하였다. UPS 인버터 출력전압의 과도상태 응답특성을 개선하고, 파라미터 변동에 강인한 특성을 얻기 위하여 2중 제어루프에서 내부 전류 제어루프는 내부 모델 제어기를 제안하였다. UPS 인버터 출력전압의 0의 정상상태 오차를 얻기 위하여 외부 전압 제어루프는 비례 제어기와 공진 제어기를 병렬로 연결한 비례-공진 전압제어기를 제안하였다. 또한, 사용자에게 쉽게 UPS의 동작 상태를 표시하기 위하여 그래픽 사용자 인터페이스를 이용한 UPS의 모니터링 시스템을 구현하였다.

• Asian Journal of Atmospheric Environment
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• 제12권1호
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• pp.17-29
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• 2018

For the first time in the city of Riyadh, the formation of $O_3$ and its relationship with NO and $NO_2$ ($NO_x$) was investigated. Throughout the summer $O_3$, NO, and $NO_2$ were collected from three locations: residential, industrial, and rural areas. During the sampling period $O_3$ concentrations exceeded 1-hour local standards a few times yet remained consistent with the standards most of the time. The $O_3$ concentrations were observed highest in the rural location and lowest in the industrial area. The diurnal variation of NO followed a double peak: one in the morning and the other in the evening, representing the traffic pattern. Early morning NO peaks were observed in the rural location, which were attributed to the movement of NO from other locations. The $O_3$ concentrations depicted typical pattern, increasing after sunrise and reaching its maximum during midday. The highest $O_3$ concentrations were observed in the rural location followed by the residential and industrial. $NO_2$ photolysis rates were 3-4 times higher compared to other similar investigations, potentially due to intense solar radiation. A strong negative correlation was observed between $NO_x$ and $O_3$ values in the industrial location indicating photochemical activities around the industrial area were higher, likely due to additional $NO_x$ emissions from industries. Regression analysis of $NO_x$ and OX ($O_3+NO_2$) indicated that in residential and industrial locations at nighttime there were large $NO_x$ independent regional contributions which is attributed to VOCs. The Weekend Effect was observed in the city potentially due to the production of the OH radical and subsequent reactions with VOCs implying that the area is VOC-sensitive.

• Journal of Animal Science and Technology
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• 제47권2호
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• pp.253-260
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• 2005

This study was conducted to utilize the wastes produced from thinning the forest as a roughage source for ruminants. Four ruminally cannulated Korean steers were used to investigate the ruminal fermentation characteristics and blood concentrations of stress-related hormones. Treatments were composed of the rice straw only (Control) and the 30% pine silage plus 70% rice straw(Pine silage) as roughages. The experiment was conducted with four replicates by a double tum over design. For sampling of blood under high temperature steers were accommodated in respiratory chamber. Concentrations of ruminal pH, volatile fatty acids and ammonia were not affected by substitution of pine silage. Mean concentration of blood thyroxine was significantly(P < 0.01) lower in the pine silage than the control. However, blood cortisol concentration was not affected by substitution of pine silage, even though it was significantly(P < 0.05) decreased after exposure for 6 hrs in high temperature. It was concluded that the pine silage using the wastes produced from thinning the forest could be use as a substitute roughage for reduction of heat stress in ruminant.

• 한국운동역학회지
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• 제22권1호
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• pp.55-63
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• 2012

The purpose of this study was to investigate the balance differences between skilled players and less-skilled players during Hakdariseogi motion of Keumgang Poomsae in Taekwondo. To achieve the study goal, total of 10 Taekwondo athletes; 5 skilled players(S, body mass: $67.0{\pm}5.7$ kg, height: $174.0{\pm}4.8$ cm, age: $20.0{\pm}2.0$ yrs) and 5 less-skilled players(LS, body mass: $73.0{\pm}4.9$ kg, height: $176.4{\pm}6.1$ cm, age: $20.8{\pm}1.3$ yrs) participated in this study. A three-dimensional motion analysis with 8 infrared cameras and one force plate whose sampling frequency as 30 Hz and 300 Hz, respectively, were performed. Participants' motion were divided into three phases which were preparation phase(P1), performing phase(P2) and maintaining phase(P3). The range and velocities of COP, the range and RMS of ground reaction torque and displacement between COM and center of BOS of each phase were computed. In this study, at P1 and P3 which were double and single stance, respectively, the range and M-L velocities of COP revealed significantly higher in LS compared with those of S(p<.05). At P2 which was single stance, LS indicated significantly higher in range of COP and ground reaction torque, and M-L velocities of COP than those of S(p<.05). The significantly shorter displacement between COM and center of BOS, however, was found in LS compared with that of S(p<.05). The results from our study indicated that S revealed more stable performance and a better posture control ability during performing Hakdariseogi motion.

• 한국운동역학회지
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• 제17권4호
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• pp.1-8
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• 2007

The purpose of this study was to investigate the difference in the stride-to-stride variability between two treadmill conditions; traditional treadmill and special treadmill whose speed can be adjusted automatically by subject's walking speed. Eight male subjects (25.1 years, 172.7 cm, 66.6 kg) were participated in treadmill walking experiment. First, preferred walking speed (PWS) of each subject was determined. Second, each subject performed walking experiment with fixed PWS condition and with free PWS condition for 10 minutes. 3D motion capture system (Motion analysis Corp., USA) with 6 cameras was used to collect motion data with sampling frequency of 120Hz. Temporal and spatial variables for stride-to-stride variability were calculated. Coefficient of variance (CV) which quantifies the amount of variability and Detrended Fluctuation Analysis (DFA) which explains the structure (self-similarity) of the variability were used for analysis. Results showed that the amount of variability during free PWS condition was greater than that of fixed PWS condition. DFA results showed that there was a statistical difference between two treadmill conditions for the variables of step length, stance time, and double support time. From these results, it is possible that traditional treadmill study might give incorrect conclusion about gait variability study. Further study is necessary to clarify these matters by considering the number of subjects, experimental time, and gait variables for the study of stride-to-stride variability.

• Journal of Applied Biological Chemistry
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• 제54권3호
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• pp.214-217
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• 2011

바나나, 오렌지 및 파인애플을 대상으로 시안화수소 처리후 잔류 특성을 평가하여 과실류에 대한 메틸브로마이드 대체 훈증제 개발 가능성을 조사하였다. 메틸브로마이드 훈증소독시 3일차에서 잔류량이 오렌지와 바나나에서는 1 mg/kg 미만 수준으로 나타났고, 파인애플의 경우에도 1 mg/kg을 조금 상회하는 수준으로 잔류허용 기준치 50 mg/kg을 훨씬 하회하고 있어 메틸브로마이드 잔류로 인한 독성문제는 우려할 수준이 아닌 것으로 평가되었다. 시안화수소 훈증소독의 경우 3일차에서 오렌지 50-60%, 바나나 70-80% 그리고 파인애플 50% 정도 분해 소실된 것으로 나타나, 잔류허용 기준치 5 mg/kg을 하회하는 1 mg/kg 미만 수준으로 나타났다. 이는 향후 메틸브로마이드 대체 훈증제로서 시안화수소의 사용이 가능함을 뒷받침하는 유용한 결과로 판단된다.

• 센서학회지
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• 제14권4호
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• pp.272-277
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• 2005

A CMOS active pixel sensor has been designed and fabricated using standard 2-poly and 4-metal $0.35{\mu}m$ CMOS processing technology. The CMOS active pixel sensor has been made up of a unit pixel having a highly sensitive PMOSFET photo-detector and electronic shutters that can control the light exposure time to the PMOSFET photo-detector, correlated-double sampling (CDS) circuits, and an 8-bit two-step flash analog to digital converter (ADC) for digital output. This sensor can obtain a stable photo signal in a wide range of light intensity. It can be realized with a special function of an electronic shutter which controls the light exposure-time in the pixel. Moreover, this sensor had obtained the digital output using an embedded ADC for the system integration. The designed and fabricated image sensor has been implemented as a $128{\times}128$ pixel array. The area of the unit pixel is $7.60{\mu}m{\times}7.85{\mu}m$ and its fill factor is about 35 %.

• Journal of Positioning, Navigation, and Timing
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• 제5권1호
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• pp.11-20
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• 2016

In this paper, a system that can collect GPS L1 C/A, GLONASS G1, and BDS B1I signals with single front-end receiver was implemented using a universal software radio peripheral (USRP) and its performance was verified. To acquire the global navigation satellite system signals, hardware was configured using USRP, antenna, external low-noise amplifier, and external oscillator. In addition, a value of optimum local oscillator frequency was selected to sample signals from three systems with L1-band with a low sampling rate as much as possible. The comparison result of C/N0 between the signal collection system using the proposed method and commercial receiver using double front-end showed that the proposed system had 0.7 ~ 0.8dB higher than that of commercial receiver for GPS L1 C/A signals and 1 ~ 2 dB lower than that of commercial receiver for GLONASS G1 and BDS B1I. Through the above results, it was verified that signals collected using the three systems with a single USRP had no significant error with that of commercial receiver. In the future, it is expected that the proposed system will be combined with software-defined radio (SDR) and advanced to a receiver that has a re-configuration channel.