• 한국정보통신학회논문지
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• 제13권11호
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• pp.2251-2259
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• 2009

네트워크를 기반으로 하나의 클러스터가 4개의 카메라로 구성된 4개의 다중 클러스터로부터 2D 영상을 조합하여 3D 입체 영상을 생성하는 알고리즘 및 시스템을 제안한다. 제안하는 기법은 다중 클러스터 환경에서 동작하고 실시간 대용량의 데이터 처리로 인한 시스템의 부하를 분산시키기 위해 네트워크를 이용한 서버-클라이언트 구조를 가진다. 아울러 성능 향상을 고려해 JPEG 압축과 램 디스크 방식을 적용한다. 4채널 16개의 카메라로부터 입력되는 입력 영상에 대해서 이진화 영상을 구하고, Sobel 및 Prewitt 등의 에지 검출 알고리즘을 적용시킨 후 영상들 간의 시차를 구한 후에 3D 입체 영상을 생성한다. 성능 분석 결과, 클라이언트에서 서버로 전송하는 전송시간은 약 0.05초가 소요되며, 4채널 16개의 카메라로부터 2D 영상을 조합하여 3D 입체 영상을 생성하는 알고리즘에 소요되는 시간은 약 0.84초가 소요된다. 이를 통해 실시간으로 다시점 및 다중 클러스터 환경에서 3D 입체 영상을 생성하는 효율적인 시스템임을 확인할 수 있었다.

• 대한토목학회논문집
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• 제14권6호
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• pp.1453-1463
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• 1994

항만의 단기 관측자료에 의한 해수의 수송은 조석잔차류와 바람응벽 등으로 해수의 평형상태를 유지하기 어렵다. 이로 인해 순 용적수송량이 만외로 유출되어야 함에도 불구하고 짧은 주기동안 만내로 유입됨으로써 담수 교체시간을 계산할 수 없었다. 본 연구는 1 조석 주기의 단기관측과 유역의 강우량 자료로부터 SCS의 유효강수량을 계산함으로써 담수 교체시간의 추정가능성을 검토하였다. 완전혼합을 가정하여, 여름철 마산만에 적용된 담수 교체시간은 외해수의 염분변화에 따라 10.9~15.3일로 분포하였다. 이는 여름철 마산만에서 순 용적 수송량(NVT)에 의한 평균 체류시간 13.9일에 상당히 근접된 값이다. 강한 성층을 이룬 홍수기의 경우 2층모델에 적용하면, 만구에서 교체시간은 1.2일로 추정되어 완전혼합모델에서 얻은 2.1일보다 작은 값이다. 이것은 홍수기에 유입된 담수가 대부분 상층을 통하여 만외로 유출되기 때문이다. 또 마산만에서 얻은 담수 유입량 $Q_r$과 교체시간 t와의 상관관계식을 완전혼합과 2층 모델의 2가지 조건으로 나타내었고, 이들이 비선형적 관계를 가지고 있음을 알 수 있었다. 이런 관계는 보스톤 내만에서 직접 하천 유입량을 조사한 결과와 근접된 형태를 보였다. 따라서 이 식들은 만의 흐름구조와 농도의 성층정도에 따라 달리 적용할 수 있고, 담수유입량의 변동에 의한 담수 교체시간의 예측을 가능케 한다. 그러므로 순 용적 수송량의 계산으로 구할 수 없는 단기관측자료는 SCS 유출곡선지수법에 의해 담수 교체시간의 추정이 가능할 것이다.

• 농촌의학ㆍ지역보건
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• 제25권2호
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• pp.441-448
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• 2000

This study was performed to investigate the prevalence and its related factors on the Clonorchis sinensis(C.S.) of inhabitants at Goksung-gun, Chollanam-do. After the population was stratified by gender, age, resident area, 651 residents living in eight villages were sampled by cluster sampling method. We interviewed the subjects to survey the various characteristics using the questionnaire, and examined stools to confirm the infection of C.S. from November to December, 1998. The prevalence of C.S. was 19.0%. The factors related with the infection of C.S. were male(adjusted odds ratio, of female=1.71, 95% confidence interval=1.07-2.72), 45-64 year old group(aOR of under 45 year old group=2.16. 95% CI=1.21-3.85), above 65 year old group(aOR of under 45 year old group=2.34, 95% CI=1.31-4.15), basin villagers(aOR of inland villagers=2.34, 95% CI=1.31-4.15), current drinker(aOR of nondrinker=1.83, 95% CI=1.12-2.98), those who took raw fish(aOR of persons who didn't it or take cooked fish=2.09, 95% CI=1.21-3.88) and persons who know the infection status(aQR of the persons who didn't know it=0.57, 95% CI=0.37-0.89). In conclusion, these results suggest that several life styles such as ingestion of raw fish, drinking habit. So we think that it is necessary to set up the efficient management programs for the treatment and prevention of C.S. infection.

• 한국임상수의학회지
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• 제14권2호
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• pp.338-348
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• 1997

The electrocardiographic (ECG) parameters on unipolar precordial chest leads in the normal Korean native goat of 343 heads as to CV$_{6}$LU, CV$_{6}$LL CV$_{6}$RU, CV$_{6}$RL and V10 have been measured with a 3-channel Elertrocardiograph and computed, analysed. All wave types as positive, negatives biphasic and flatting in the P and T waves appeared in all leads but any special wave type was not shown more than 60%. Average amplitudes with the highest frequent rate in P wave were 81.4$\pm$32.0 $\mu $V (52.3%), 59.6$\pm $ 27.5 $\mu $V (50.5 %) of Positive type in leads CV$_{6}$LU and CV$_{6}$LL, and -5fl.5$\pm $22.6 $\mu $V (44.0%) of negative type in leads VIO, and 51.3% and 44% of flatting type in leads CV$_{6}$RU and CV$_{6}$RL, but flatting type of clinic form appeared frequent rate between 53% and 77% in all leads. In T wave, average amplitudes with the highest frequent rate were 265.0$\pm $97.1 $\mu $V (54.0%) and 212.2$\pm $90.7 $\mu $V (57.0%) of positive type in leads CV$_{6}$LL and CV$_{6}$RL, and -252.8$\pm $90.7 $\mu $V (56.6%) of negative in lead V10, but amplitudes of T waves that positive and negative type appeared similarity frequent ra蛇 ware 208.7$\pm $99.7 $\mu $V (42.1%), -159.0$\pm $81.6 (43.8%) in lead CV$_{6}$LU and 153.2$\pm $139.0 $\mu $V (47.3%), -130.0$\pm $81.4 (43.2%) in lead CV$_{6}$RU, Amplitudes of QRS complex wave forms showed the highest frequent rate were 218.2$\pm $96.4 $\mu $V (47.8%), 308.3$\pm $135.2 $\mu $V (46.8 %), 232.8$\pm $126.5 $\mu $V (58.5%) and 225.3$\pm $89.6 $\mu $V (54.9%) of R type in the leeds CV$_{6}$LU, CV$_{6}$LL, CV$_{6}$RU and CV$_{6}$RL, and were -92.5$\pm $79.1 $\mu $V,479.0 $\pm $116.6 $\mu $V (33.2%) and 212.1 $\pm $86.7 $\mu $V (32.8%) of QR and 05 type in the lead V10. These results in the V10, CV$_{6}$RU, CV$_{6}$RL, CV$_{6}$LU, CV$_{6}$LL. may be not starve to purpose of unipolar precordial chest leads.

• 한국구조물진단유지관리공학회 논문집
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• 제17권2호
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• pp.1-9
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• 2013

최근 초고층 및 초장대와 같은 대형 구조물들이 시공되고 있으며, 이에 대한 구조물 건전성 모니터링 기술들이 연구되고 있다. 하지만 기존의 기술들은 계측 센서의 관리와 센서로부터 계측된 데이터에 효율적으로 access하지 못하고 있다. 본 논문에서는 구조물 건전성 모니터링을 위한 증강현실 기반 센서 위치인식 및 데이터 시각화 기술을 소개한다. 모바일 디바이스에 내장된 GPS를 통하여 센서와 사용자 간의 거리를 파악하게 된다. 뿐만 아니라, 센서로부터 계측된 데이터는 위치정보시스템 서버에 저장되며, RSS방식을 통해 전송되어 사용자가 모바일 디바이스를 통해 쉽게 계측 데이터를 가시화 할 수 있게 된다. 이 기술을 이용하여 사용자는 센서의 위치인식을 통해 계측센서를 관리하고, 계측 데이터를 시각화하여 시간과 공간에 제약 없이 구조물의 건전성을 모니터링 할 수 있게 된다.

• Imaging Science in Dentistry
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• 제48권1호
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• pp.11-19
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• 2018

Purpose: This study compared the diagnostic accuracy of cone-beam computed tomography (CBCT) scans obtained with 2 CBCT systems with high- and low-resolution modes for the detection of root perforations in endodontically treated mandibular molars. Materials and Methods: The root canals of 72 mandibular molars were cleaned and shaped. Perforations measuring 0.2, 0.3, and 0.4 mm in diameter were created at the furcation area of 48 roots, simulating strip perforations, or on the external surfaces of 48 roots, simulating root perforations. Forty-eight roots remained intact(control group). The roots were filled using gutta-percha (Gapadent, Tianjin, China) and AH26 sealer (Dentsply Maillefer, Ballaigues, Switzerland). The CBCT scans were obtained using the NewTom 3G (QR srl, Verona, Italy) and Cranex 3D (Soredex, Helsinki, Finland) CBCT systems in high- and low-resolution modes, and were evaluated by 2 observers. The chi-square test was used to assess the nominal variables. Results: In strip perforations, the accuracies of low- and high-resolution modes were 75% and 83% for NewTom 3G and 67% and 69% for Cranex 3D. In root perforations, the accuracies of low- and high-resolution modes were 79% and 83% for NewTom 3G and was 56% and 73% for Cranex 3D. Conclusion: The accuracy of the 2 CBCT systems was different for the detection of strip and root perforations. The Cranex 3D had non-significantly higher accuracy than the NewTom 3G. In both scanners, the high-resolution mode yielded significantly higher accuracy than the low-resolution mode. The diagnostic accuracy of CBCT scans was not affected by the perforation diameter.

• KIEE International Transactions on Electrophysics and Applications
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• 제5C권3호
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• pp.102-110
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• 2005

Piezoelectric transformers(PT) are expected to be small, thin and highly efficient, and which are attractive as a transformer with high power density for step down voltage. For these reasons, we have attempted to develop a step-down PT for the miniaturized adaptor. We propose a PT, operating in thickness extensional vibration mode for step-down voltage. This PT consists of a multi-layered construction in the thickness direction. In order to develop the step-down PT of 10 W class and turn ratio of 0.1 with high efficiency and miniaturization, the piezoelectric ceramics and PT designs are estimated with a variety of characteristics. The basic composition of piezoelectric ceramics consists of ternary yPb(Zr$_{x}$Ti$_{1-x}$)O$_{3}$-(1-y)Pb(Mn$_{1/3}$Nb1$_{1/3}$Sb$_{1/3}$)O$_{3}$. In the piezoelectric characteristics evaluations, at y=0.95 and x=0.505, the electromechanical coupling factor(K$_{p}$) is 58$\%$, piezoelectric strain constant(d$_{33}$) is 270 pC/N, mechanical quality factor(Qr$_{m}$) is 1520, permittivity($\varepsilon$/ 0) is 1500, and Curie temperature is 350 $^{\circ}C$. At y = 0.90 and x = 0.500, kp is 56$\%$, d33 is 250 pC/N, Q$_{m}$ is 1820, $\varepsilon$$_{33}$$^{T}$/$\varepsilon$$_{0}$ is 1120, and Curie temperature is 290 $^{\circ}C$. It shows the excellent properties at morphotropic phase boundary regions. PZT-PMNS ceramic may be available for high power piezoelectric devices such as PTs. The design of step-down PTs for adaptor proposes a multi-layer structure to overcome some structural defects of conventional PTs. In order to design PTs and analyze their performances, the finite element analysis and equivalent circuit analysis method are applied. The maximum peak of gain G as a first mode for thickness extensional vibration occurs near 0.85 MHz at load resistance of 10 .The peak of second mode at 1.7 MHz is 0.12 and the efficiency is 92$\%$.

• 한국통신학회논문지
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• 제40권3호
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• pp.497-505
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• 2015

기존의 보안 Wi-Fi 네트워크는 사용자가 AP(Access Point)의 암호에 맞춰야 하므로 사용이 불편하며, 사용자들이 암호를 공유하므로 시간이 갈수록 보안성이 낮아지는 문제점을 갖고 있다. 이를 해결하기 위해 사용자마다 별도의 가상 Wi-Fi 네트워크를 할당하는 방안을 제안한다. 이 방법에서는 각 사용자가 자신만의 Wi-Fi 네트워크를 가지므로 사용자 중심의 네트워크 설정이 가능하다. 사용자는 자신의 기기에 나름대로의 SSID(Service Set IDentifier)와 암호를 미리 설정해 두며 AP는 자신의 공개키를 적절한 방법으로 공개한다. AP는 또한 사용자들이 언제나 접속할 수 있는 공개채널을 유지한다. 사용자 요청이 있을 때 사용자 기기는 연결 요청 메시지를 보내는데 이 메시지에는 AP의 공개키로 암호화된 사용자 기기의 SSID와 암호가 실려 있다. 연결 요청 메시지를 받은 AP는 해당 SSID 및 암호가 설정된 새로운 가상의 AP를 생성하는데 이 가상 AP는 해당 사용자만 사용할 수 있는 전용 AP라고 할 수 있다. 이렇게 만들어지는 가상 네트워크는 비밀번호를 여러 사용자가 공유하지 않으므로 보안성이 높다. 또 이 가상 네트워크는 네트워크가 사용자 기기에 맞춰 스스로를 설정하기 때문에 사용의 편의성이 높다. 새 방법이 제공하는 보안성과 편리성에도 불구하고 기존의 Wi-Fi 네트워크에 비해 별다른 전송 능력 저하는 나타나지 않음을 실험을 통해 확인하였다.

• 한국실내디자인학회논문집
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• 제26권1호
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• pp.33-42
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• 2017

Interior design especially the design developments for commercial spaces should ensure the economy of spaces. This is the marketing for space. It is necessary to understand the design elements of commercial space for the efficient using of digital media of space marketing. In this research decided to design application schemes for shopping mall by searching fashion shopping behaviors of users with persona-base scenario approach. Collected the information of users behavior base on case analysis of advance research to make personas. And develop scenario base personas for knowing the needs of users. And then made 4 schemes as the solution. Scheme 1. Customers can get the information and communication with the staff through with media screen in one room of shopping mall. The data of customers can be recorded for providing information or product recommendation personality. Forecast to preferred by group trip or customers that don't like walking around in shopping mall. Scheme 2. Install a media screen at entrance of a store in shopping mall and show special effect to raise customers' attention who walk through from the front of the store. Through with this customers will stay for long time and raise curiosity to get in the store. And the media screen also provide information of store and products. Scheme 3. Customers can get the information of products with using smart phone to scan QR cord in labels of products and record. Customers can finish whole shopping behaviors without the help of store staff. And can make buying decision even have left shopping mall as a online mode. Scheme 4. Store managers can record the products and the environment of store with 360 camera and update to website. Then customers can browse the virtual space with VR glasses. That make customers can have the real shopping experience without being in the store. In this study, have presented schemes of digital media in commercial space. But there are various of commercial space. In this study was presented schemes for shopping mall by searching fashion shopping behaviors of users. And look forward the researches about specific space setting and other type of commercial space for space development.

• Archives of Pharmacal Research
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• 제26권8호
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• pp.585-590
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• 2003

Activity-guided fractionation of the EtOAc-soluble extract of the whole plants of Sida acuta using a bioassay based on the induction of quinone reductase (OR) in cultured Hepa 1c1c7 mouse hepatoma cells, led to the isolation of ten active compounds of previously known structure, quindolinone (1), cryptolepinone (2), 11-methoxyquindoline (3), N-trans-feruloyltyramine (4), vomifoliol (5), loliolide (6), 4-ketopinoresinol (7), scopoletin (8), evofolin-A (9), and evofolin-B (10), along with five inactive compounds of known structure, ferulic acid, sinapic acid, syringic acid, ($\pm$)-syringaresinol, and vanillic acid. These isolates were identified by physical and spectral data measurement. A new derivative of quindolinone, 5,10-dimethylquindolin-11-one (1a) was synthesized and characterized spectroscopically. Of the active substances, compounds 1-3 and 1a exhibited the most potent QR activity, with observed CD (concentration required to double induction) values ranging from 0.01 to 0.12 $\mu$ g/mL. Six compounds were then evaluated in a mouse mammary organ culture assay, with cryptolepinone (2), N-trans-feruloyltyramine (4), and 5,10-dimethylquindolin-11-one (1a) found to exhibit 83.3, 75.0, and 66.7% inhibition of 7,12-dimethylbenz[a]anthracene-induced preneoplastic lesions, respectively, at a dose of 10 $\mu\textrm{g}$/mL.