• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.2
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• pp.87-93
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• 2010

This paper presents a low-power, wide tuning range VCO with automatic two-step negative-Gm calibration loop to compensate for the process, voltage and temperature variation. To cover the wide tuning range, digital automatic negative-Gm tuning loop and analog automatic amplitude calibration loop are used. Adaptive body biasing (ABB) technique is also adopted to minimize the power consumption by lowering the threshold voltage of transistors in the negative-Gm core. The power consumption is 2 mA to 6mA from a 1.2 V supply. The VCO tuning range is 2.65 GHz, from 2.35 GHz to 5 GHz. And the phase noise is -117 dBc/Hz at the 1 MHz offset when the center frequency is 3.2 GHz.

• The Journal of the Korea Contents Association
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• v.13 no.4
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• pp.290-299
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• 2013

This study included 198 patients who underwent prospectively electrocardiogram-triggered high-pitch spiral mode(FLASH mode) in cardiac CT for health check: 123 patients who underwent manual exposure control(Group A) and 75 patients who underwent automatic exposure control(Group B). Patients were classified according to BMI grades: Grade 1, Grade 2, Grade 3, Grade 4. Radiation dose, objective and subjective image quality between two groups were compared. In Group B, tube voltage were significantly decreased in all BMI grades. Both $CTDI_{vol}$ and effective dose were significantly reduced in the BMI Grade 1, 3, and 4 whereas they were slightly reduced in the Grade 2(p>0.05), SNR was significantly decreased in the Grade 1 and increased in the Grade 3(p<0.05), but there was no significant difference in the Grade 2, 4 between the two groups(p>0.05). CNR was significantly decreased in the Grade 1(p<0.05), and there was no significant difference in the Grade 2, 3, 4 between the two groups(p>0.05). The subjective image quality showed no significant difference in all BMI Grades between the two groups(p>0.05). Automatic exposure control can lead to a significant reduction of radiation exposure dose without degradation of subjective image quality.

• ICROS
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• v.2 no.1
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• pp.72-84
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• 1996

• Proceedings of the Acoustical Society of Korea Conference
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• autumn
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• pp.245-248
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• 2004

본 논문에서는 텔레비전 수신기에서 채널 변경에 따른 음량 자동 보정 방법에 대해서 기술하고자 한다. 지금까지 텔레비전 수상기에서는 사용자가 방송 채널을 전환하는 경우 각 방송 채널마다 음량 레벨이 조금씩 다르다는 것을 느끼게 된다. 그러므로 이러한 채널 변경에 따른 음량 변화를 조정하기 위해 청취자가 리모컨으로 볼률을 조절하는 불편함을 줄이기 위해 자동으로 음량 변화를 보정하는 것이 요구된다. 본 논문은 채널 변경에 따른 음량 변화와 Dynamic Range 가 너무 큰 오디오 신호에 대해 자동으로 음량을 보정함으로써 청취자가 볼륨을 조절하는 불편함을 줄이는 자동 음량 보정 알고리즘을 제안하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2019.10a
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• pp.295-298
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• 2019

본 논문은 기존의 수동으로 높이 조절만 가능한 단순 의자를 탈피하여 자라나는 아이의 신장과 체형에 맞게 의자 높이를 자동으로 조절해주는 스마트 의자를 제안한다. 본 논문의 주요 특징은 다음과 같다. 첫째, 초음파센서와 무게센서를 사용하여 아이의 신장과 체중을 측정함으로써 신체에 맞게 자동으로 의자의 각도와 높낮이를 조절해준다. 둘째, 센서를 통해 실시간으로 데이터를 수집하여 App 화면에 건강 상태를 보여주고 아이 등급표와 비교하여 아이의 성장률을 가시적으로 보여준다. 셋째, 압력 센서를 이용하여 아이의 자세 상태를 보여주고 App 알림과 데이터 분석으로 아이의 자세 교정에 도움을 준다. 넷째, 신호를 전달하면 지정된 자리로 의자가 자동으로 이동하는 기능을 제공한다. 제안된 시스템은 IoT 기술을 접목함으로써 성장이 빠른 영유아를 키우는 가정을 대상으로 의자 교체에 필요한 비용 절감 효과와 바쁜 현대인들을 위해 아이의 건강관리를 보다 효율적으로 돕는 것을 목표로 한다.

• Journal of the Korea Computer Industry Society
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• v.9 no.2
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• pp.69-76
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• 2008

This paper implement an Camcorder NTSC camera autofocus control system on the DSP Board. The information of camera lens control obtain the only brightness simple image processing from the NTSC camcoder camera image. The exact focus makes the exact boundaries. The camera lens control that the increase sum of the useful ingredient values. Useful value obtained experiment value. Also noise is except because a big value of the ingredients so that obtained focus more accurate value.

• Journal of Bio-Environment Control
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• v.5 no.2
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• pp.145-151
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• 1996

The effectiveness of physiological or chemical acid - alkali solution was investigated as the method to control pH value of nutrient solution in hydroponics dynamically. Lettuces were cultivated using NH$_4$H$_2$PO$_4$ as physiological acid and NaNO$_3$ as physiological alkali or H$_2$SO$_4$ as chemical acid in dynamic control system. The pH of nutrient solution was controlled satisfactorily in the range of pH 5.5-6.5, regardless of treatments. Chemical acid changed pH of solution faster than chemical acid when supplied to the nutrient solution. Any of them did not show any harmful symptom. It is recommended that chemical acid is preferred during the growing stage and physiological acid like as NH$_4$H$_2$PO$_4$ is preferred from several days before harvest stage.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.48 no.4
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• pp.80-85
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• 2011

A time-pickoff circuit used for time measurement suffers from a timing error due to the dependence of the generation time of a timing pulse on the size of the input signal, i.e., time walk. In this study, a time-pickoff method, which employs an automatic gain control (AGC) circuit, is proposed for reducing the timing error. The AGC circuit is added to the input of the comparator, and it renders the sizes of input signals of the comparator relatively uniform. The performance of the proposed time-pickoff method is analyzed using the SPICE simulation, and experiments are performed to confirm the analytical results. The measured time walk is reduced to 2.000 ns by 65% for input signals with a dynamic range of 20 dB as compared to a typical leading-edge discriminator.

• Proceedings of the Korea Information Processing Society Conference
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• 2023.11a
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• pp.128-129
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• 2023

해당 논문은 라즈베리파이를 이용한 온실의 온습도 자동제어 시스템에 관한 연구를 다룬다. 이 시스템은 특정 작물에 대한 최적의 생육환경 제공을 위해 자동으로 온도 및 습도를 측정하고 조절한다. 관리자는 수동으로도 각 기능을 제어할 수 있다. 온습도를 제어하기 위한 방법으로 자연환기, 인공환기, 온실내부 물분사, 열선작동의 방법을 사용한다. 자동화된 온습도 제어 시스템으로 농산물의 생산량 및 품질을 늘림과 동시에 온실 관리에 투자되는 자원을 줄일 수 있어 농업인들의 농업경쟁력을 향상시킬 수 있다.

• Horticultural Science & Technology
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• v.17 no.3
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• pp.325-328
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• 1999

This experiment was conducted to investigate the effect of the automatic control of night temperature and day length on the flower bud initiation growth responses and yield of strawberries. Flower bud initiation was observed only 14 days after treatment in plants forced with automatic system but not in plants forced with traditional methods, and flower bud development was further progressed by an automatic system. In genernal, the crown diameter of runner plants derived from strawberries grown with the automatic system was smaller than those from the plants grown under hand-operated system and this tendency was clear in plants placed at middle and low position during forcing. The rate of transpiration was higher in plants treated with hand operated method but the content of chlorophyll was lower than those treated with the automatic system. Results indicated that automatic system has an advantage in stimulation of flower bud initiation and improving the quility of runner plants.