• Land and Housing Review
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• v.6 no.4
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• pp.215-220
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• 2015

The purpose of this study was to comparative analyses of energy performance in apartment houses adopted window frame-type natural ventilation, under-floor air distribution ventilation and heat recovery ventilation. As the object of energy simulation, the three type ventilation system with area of $84m^2$ was selected in apartment house. As a result, when the ECO2 simulation was performed, the 1st requirement quantity per annual were $159.9kWh/m^2yr$(CASE1, Natural Ventilation), $179.7kWh/m^2yr$(CASE2, Under-floor Air Distribution Ventilation) and $161.0kWh/m^2yr$(CASE3, Heat Recovery Ventilation).

• Journal of the Korea Institute of Information and Communication Engineering
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• v.6 no.3
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• pp.405-409
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• 2002

Recently, the FCC commissioners approved limited uses of UWB, and have promised to review the standards to explore the potential of more flexible standards and to address the operation of additional types of UWB operations and technology. In this paper we study performances of UWB communication system according to M-ary schemes with BCH code. And under the AWGN channel, we analysis and compare error probability, the number of M-ary schemes to the two methods that pulse position modulation and pulse amplitude modulation.

• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1929-1931
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• 2003

본 연구에서 제안하는 마이크로 밸브는 열공압 방식으로 구동되고 제작비용이 저렴한 indium tin oxide (ITO) 및 polydimethylsiloxane (PDMS)로 제작되었다. 제안된 마이크로 밸브의 구조는 ITO 히터, SU-8 층, PDMS membrane, 그리고 PDMS 채널로 구성되어 있다. 제작된 열공압 구동기의 PDMS membrane의 변위는 현미경의 초점 거리의 변화로 측정하였으며 히터에 160mW 전력 인가 시 변위는 대략 $132{\mu}m$이다. 마이크로 밸브의 히터에 인가 전력에 따른 유량측정은 DI water를 사용하여 측정하였고 inlet 압력은 1.2kpa를 인가하여 측정하였다. 히터 인가 전력이 영일 경우 채널 폭이 $200{\mu}m$와 $400{\mu}m$인 마이크로 밸브의 유량은 각각 대략 $36{\mu}{\el}$/min과 $110{\mu}{\el}$/min 이었다. 채널 폭이 $200{\mu}m$와 $400{\mu}m$인 마이크로 밸브의 유량은 히터 인가 전력이 각각 70mW와 160mW에서 영이 되었다.

• The Korean Journal of Nuclear Medicine Technology
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• v.26 no.2
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• pp.15-19
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• 2022

Purpose [⁶⁸Ga]PSMA-11 is needed the high reproducibility, excellent radiochemical yield and purity. In term of radiation safety, the radiation exposure of operator for its production also should be considered. In this work, we performed a comparative study for the fully automated synthesis of [⁶⁸Ga]PSMA-11 between non-cassette type and cassette type. Materials and Methods Two different type of modules (TRACERlab FX N pro for non-cassette type and BIKBox for cassette type) were used for the automated production of [⁶⁸Ga]PSMA-11. According to the previously identified elution profile, Only 2.5 ml with high radioactivity was used for the reaction. After adjusting the pH of the reaction solution with HEPES buffer solution, the precursor was added and reacted with at 95 ℃ for 15 minutes. The reaction mixture was separated and purified using a C18 light cartridge. The product was eluted with 50% EtOH/saline solution and diluted with saline. It was completed by sterilizing filter. In the non-cassette type, the aforementioned process must be prepared directly. However, in the cassette method, synthesis was possible simply by installing a kit that was already completed. Results Both total [⁶⁸Ga]PSMA-11 production time were 25±3(non-cassette type) and 23±3 minutes(cassette type). The radiochemical yield of the non-cassette type(65.5±5.7%) was higher than that of the cassette type(61.6±4.8%) after sterilization filter. The non-cassette type took about 120 minutes of preparation time before synthesis due to washing of synthesizer and reagent preparation. However, since the cassette type does not require washing and reagent preparation, it took about 20 minutes to prepare before synthesis. Both type of synthesizer had a radiochemical high purity(>99%). Conclusion The non-cassette type production of [⁶⁸Ga]PSMA-11 showed higher radiochemical yield and lower cost than the cassette type. However, The cassette type has an advantage in terms of preparation time, convenience, and equipment maintenance.

• The KIPS Transactions:PartC
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• v.19C no.4
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• pp.239-246
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• 2012

The function of location estimation in WPAN has been studied and specified on the ultra wide band optionally. But the devices based on CSS(Chirp Spread Spectrum) specification has been used widely in the market because of its functionality, cheapness and support of development. As the CSS device uses 2.4GHz for a carrier frequency and the sampling frequency is lower than that of the UWB, the resolution of a timestamp is very coarse. Then actually the error of a measured distance is very large about 30cm~1m at 10 m depart. And the location error in ($10m{\times}10m$) environment is known as about 1m~2m. So for some applications which require more accurate location information, it is very natural and important to develop a sophisticated post processing algorithm after distance measurements. In this paper, we have studied extended Kalman filter with the frequency offsets of anchor nodes, and proposed a novel algorithm frequency offset compensated extended Kalman filter. The frequency offsets are composed with a variable as a common frequency offset and constants as individual frequency offsets. The proposed algorithm shows that the accurate location estimation, less than 10cm distance error, with CSS WPAN nodes is possible practically.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.595-597
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• 2015

In recent years, global Internet of Things is being fostered by strategic industry in major countries (IoT: Internet of Things) technology is the future Internet -based context-aware infrastructure capable of communication between objects and things. Existing technology was only a single device control via P2M (Puman to Machine) method and simple sensor data to someone directly control the devices down command. However, a kind of IoT Machine Socialization of devices, each device uses an internal feature information, and M2M (Machine to Machine) devices in ways that expand the overall scenario collaboration system through the Device Manager. In this paper, an algorithm of the whole system of the Machine Socialization for changing the system of the conventional system of P2M by M2M, and analysis.

• Journal of dental hygiene science
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• v.15 no.1
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• pp.12-17
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• 2015

The purpose of this study was to evaluate the marginal and internal gap of metal coping fabricated using additive manufacturing (AM) group and subtractive manufacturing (SM) group by dental computer-aided design (CAD)/computer-aided manufacturing (CAM) systems. Twenty same cases of stone models of abutment teeth 16 by the universal numbering system were manufactured and scanned. Ten metal copings of control group were fabricated using SM and ten metal coping of experimental group were fabricated using AM. Marginal and internal gap of copings were measured using the silicone replica technique and digital microscope (${\times}140$). The data were analyzed using IBM SPSS 21.0 Statistical Software for independent samples t-test (${\alpha}=0.05$). Mean${\pm}$ standard deviation (SD) of marginal and internal gap total size of SM group was $101.00{\pm}40.33{\mu}m$ of AM group was $83.61{\pm}40.37{\mu}m$. Mean${\pm}$SD of marginal and internal gap total size of SM group was significantly greater than that of AM group (p<0.05). This study showed that AM metal copings had a better marginal and internal gap than SM metal copings.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.210.2-210.2
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• 2013

현재 국내의 상용화된 디지털 방식 X-선 영상장치에서 간접변환방식은 대부분 CsI를 사용하고 있으며, X-선 흡수에 의해 전기적 신호를 발생시키는 직접변환방식은 Amorphous Selenium(a-Se)을 사용한다. a-Se은 진공 중에 녹는점이 낮아 증착시 substrate의 온도에 따라 민감한 변화를 보인다. 본 연구에서는 간접변환방식에 비해 높은 영상의 질을 획득할 수 있는 직접변환방식의 a-Se기반 X-선 검출기 제작 시 substrate에 인가된 온도에 따른 특성을 연구하여 최적화 된 substrate의 온도를 알고자 한다. 본 실험에서는 glass에 투명한 전극물질인 Indium Tin Oxide (ITO)가 electrode로 형성된 substrate를 사용하였으며 그 상단에 a-Se을 Physical Vapor Deposition (PVD)방식을 거쳐 X-선 검출기 샘플을 제작하였다. PVD 공정 시 네 개의 보트에 a-Se 시료를 각각 100g씩 총 400g을 넣고, $5{\times}10-5Torr$까지 진공도를 낮추었다. 보트의 온도는 $270^{\circ}C$에서 40분 $290^{\circ}C$에서 90분으로 온도를 인가하여 a-Se을 기화시켜 증착하였다. 증착 시 substrate 온도를 각각 $20^{\circ}C$, $40^{\circ}C$, $60^{\circ}C$, $70^{\circ}C$ 네 종류로 나누어 실험을 진행하였다. 끝으로 증착된 a-Se 상단에 Au를 PVD방식으로 electrode를 형성시켜 a-Se기반의 X-선 검출기 샘플 제작을 완료하였다. 제작된 a-Se기반의 X-선 검출기 샘플의 두께는 80에서 $85{\mu}m$로 온도에 따른 차이가 없었다. 이후에 전기적 특성을 평가하기위해 electrometer와 oscilloscope를 이용하여 Dark current와 Sensitivity를 측정하여 Signal to Noise Ratio(SNR)로 도출하였으며 Scanning Electron Microscope(SEM) 표면 uniformity를 관찰하였다. 또한 제작된 a-Se기반 X-선 검출기 샘플의 hole collection 성능을 확인하고자 mobility를 측정하였다. 측정결과 a-Se의 work function을 고려한 $10V/{\mu}m$기준에서 70kV, 100mA, 0.03sec의 조건의 X-선을 조사 하였을 때 Sensitivity는 세 종류의 검출기 샘플이 15nC/mR-cm2에서 18nC/mR-cm2으로 비슷한 양상을 나타내었지만, substrate온도가 $70^{\circ}C$때의 샘플은 10nC/mR-cm2이하로 저감됨을 알 수 있었다. 그리고 substrate온도 $60^{\circ}C$에서 제작된 검출기 샘플의 전기적 특성이 SNR로 환산 시, 15.812로 가장 우수한 전기적 특성을 나타내어 최적화 된 온도임을 알 수 있었다. SEM촬영 시 온도상승에 따라 표면 uniformity가 우수하였으며, Mobility lifetime에서는 $60^{\circ}C$에서 제작된 검출기 샘플이 deep trap 수치가 높아 hole이 $0.04584cm2/V{\cdot}sec$로 $0.00174cm2/V{\cdot}sec$의 electron보다 26.34배가량 빠른 것을 확인하였다. 본 연구를 통해 a-Se증착 시, substrate에 인가된 온도는 균일한 박막의 형성 및 표면구조에 영향을 미치며 온도가 증가할수록 안정적인 전기적 특성을 나타내지만 $70^{\circ}C$이상일 시, a-Se층의 결정화가 생겨 deep trap을 발생시켜 전기적 특성이 저하됨을 확인 할 수 있었다. 따라서 증착 시의 substrate의 온도 최적화는 a-Se기반 X-선 검출기의 안전성 및 성능향상을 위해 불가피한 요소가 된다고 사료된다.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.5 no.4
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• pp.43-51
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• 1991

본 논문에서는 전력선 반송통신을 이용한 가정내 전기기기의 감시제어 시스템인 "전동선 HMCS"를 개발했다. 통신방식은 양방향으로서 반송파 주파수 125[kHz]의 FSK디지탈 신호를 전등선에 중첩시키는 방식이며, 제어방식은 Polling 방식을 채용했다. 그리고 시스템의 송신출력은 4Vp-p이고, 수신감도는 CISPR 잡음 규제등을 고려하여 10[mV] 이상으로 설계하였다. 개발 시스템의 성능은 58[dB] 시스템 여유도와 1.78$\times$10-7의 에러확률을 갖는다.에러확률을 갖는다.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 1996.11a
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• pp.151-159
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• 1996

본 논문에서는 right-to-left 형태의 멱승 연산에 적합한 고속 모듈라 감소 알고리듬을 제안하고 이를 여러 멱승 방식에 적용했을 경우의 계산 속도 및 메모리 사용효율을 기존의 방식들과 비교하였다. 분석 결과, 기존의 방식보다 고속으로 멱승을 수행할 수 있고 m-ary 방식이나 window 방식에서는 사용 메모리를 줄일 수 있다.