• Journal of the Korean Society of Radiology
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• v.15 no.7
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• pp.935-942
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• 2021

Involuntary movement of internal organs by respiration is a factor that greatly affects the results of radiotherapy and diagnosis. In this study, a moving phantom was fabricated to simulate the movement of an organ or a tumor according to respiration, and ¹⁸F-FDG PET/CT scan images were acquired under various respiratory simulating conditions to analyze the movement range of the tumor movement by respiration, the level of artifacts according to the size of the tumor and the maximum standardized uptake value (SUVmax). Based on Windows CE 6.0 as the operating system, using electric actuator, electric actuator positioning driver, and programmable logic controller (PLC), the position and speed control module was operated normally at a moving distance of 0-5 cm and 10, 15, and 20 reciprocations. For sphere diameters of 10, 13, 17, 22, 28, and 37 mm at a delay time of 100 minutes, 80.4%, 99.5%, 107.9%, 113.1%, 128.0%, and 124.8%, respectively were measured. When the moving distance was the same, the difference according to the respiratory rate was insignificant. When the number of breaths is 20 and the moving distance is 1 cm, 2 cm, 3 cm, and 5 cm, as the moving distance increased at the sphere diameters of 10, 13, 17, 22, 28, and 37 mm, the ability to distinguish images from smaller spheres deteriorated. When the moving distance is 5 cm compared to the still image, the maximum values of the standard intake coefficient were 18.0%, 23.7%, 29.3%, 38.4%, 49.0%, and 67.4% for sphere diameters of 10, 13, 17, 22, 28, and 37 mm, respectively.

• Journal of IKEEE
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• v.20 no.2
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• pp.184-187
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• 2016

In this paper, we propose the sensor and the signal duplicator for the automatic building control. Developed duplicator realizes the sensor data collection apparatus and mimics the measured data and, thus, reduces the construction cost by using logical communication layer. Furthermore, the system supports the open protocols and can be associated with HMI(Human Machine Interface) used on the market. Developed duplicator is proved to be functional within the real environment. Measurement error rate, operating temperature, and operating humidity show very good results by the certified testing apparatus and organization.

• Proceedings of the KIPE Conference
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• 2013.11a
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• pp.83-84
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• 2013

최근 국내에서 진행중인 스마트 그리드(Smart Grid) 사업 분야에 속해 있는 스마트 운송(Smart Transportation) 사업의 하나로 전기차 운영이 핵심이 되어 진행이 되고 있다. 그러나 실제적으로 전기차를 원활히 운영하기 위해서는 극복해야 할 여러 문제가 있으며 대표적으로 주행 거리를 좌우하는 배터리 용량 문제와 고객이 어디서든 전기차를 사용하고 충전하는데 불편이 없을 만큼 충분한 충전 인프라 구축 문제가 있다. 충전 인프라는 현재, 완속 충전기와 급속 충전기로 구성되어 있으나 본 논문에서는 완속 충전기에 한정하여 서술하였고 인프라 구축에 있어 표준화 일환으로 미국자동차기술학회에서 제시하는 SAE-J1772 규격에 맞추어 개발한 자사의 완속 충전기에 2012년 독일과 미국의 자동차 업체 주도로 발표된 국제표준(ISO/IEC 15118, Vehicle-to-Grid Communication Interface) 기술 규격이며 향후 충전 인프라에 적용 예상이 되는 PLC 통신 방식을 적용한 완속 충전기 개발에 관하여 소개하도록 하였다.

• IMMUNE NETWORK
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• v.5 no.2
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• pp.99-104
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• 2005

Background: Malignant gliomas are the most common primary tumors in the central nervous system. Methods: We investigated the combined effect of PG490 and LPS on the induction of the apoptotic pathway in human astroglioma cells. Results: Treatment of U87 cells with combination of 50nM of PG490 and $50{\mu}g/ml$ of LPS resulted in increased internucleosomal DNA fragmentation, cleavage of PLC-${\gamma}1$, and downregulation of cIAP1 and XIAP. The combination of LPS and PG490 treatment-induced apoptosis is mediated through the activation of caspase, which is inhibited by the caspase inhibitor, z-VAD-fmk. Also, release of cytochrome c was found in PG490 and LPS-cotreated U87 cell. Conclusion: Taken together, combination of PG490 and LPS appears to be a potent inducer of apoptosis in astrogliaoma cells, and might have some benefit in the treatment of glioma patients.

• BMB Reports
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• v.28 no.4
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• pp.316-322
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• 1995

The GTPase activating protein (GAP) can function both as a negative regulator and an effector of $p21^{ras}$. Overexpression of GAP in NIH-3T3 cells has been shown to inhibit transformation by ms or src. To investigate the function of GAP in a differentiative system, we overexpressed this protein in the nerve growth factor (NGF)-responsive PC12 cell line. Two-fold overexpression of GAP caused a delay of several days in the onset of NGF- but not FGF-induced neuronal differentiation of PC12 cells. However, the NGF-induced activation or tyrosine phosphorylation of upstream (Trk, PLC-${\gamma}1$, SHC) and downstream (B-Raf and $p44^{mapk/erk1}$) components of $p21^{ras}$, signalling cascade was not altered by GAP overexpression. Therefore, the change of phenotype induced by GAP was probably not due to GAP functioning as a negative regulator of $p21^{ras}$. Rather, we found that NGF-induced tyrosine phosphorylation of SNT, a specific target of neurotrophin-induced tyrosine kinase activity, was inhibited by GAP overexpression. SNT is thought to function upstream or independent of $p21^{ras}$. Thus in PC12 cells, overexpressed GAP may control the rate of neuronal differentiation through a pathway involving SNT rather than the $p21^{ras}$ signalling pathway.

• Wind and Structures
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• v.18 no.5
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• pp.473-495
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• 2014

Localized wind events, in the form of tornadoes and downbursts, are the main cause of the large number of failure incidents of electrical transmission line structures worldwide. In this study, a numerical model has been developed to study the behaviour of self-supported transmission lines under various tornado events. The tornado wind fields used were based on a full three-dimensional computational fluid dynamics analysis that was developed in an earlier study. A three-dimensional finite element model of an existing self-supported transmission line was developed. The tornado velocity wind fields were then used to predict the forces applied to the modelled transmission line system. A comprehensive parametric study was performed in order to assess the effects of the location of the tornado relative to the transmission line under F2 and F4 tornado wind fields. The study was used to identify critical tornado configurations which can be used when designing transmission line systems. The results were used to assess the sensitivity of the members' axial forces to changes in the location of the tornado relative to the transmission line. The results were then used to explain the behaviour of the transmission line when subjected to the identified critical tornado configurations.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.72-74
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• 2005

전력선통신은 현재 홈 네트워크 및 검침기술과 같은 다양한 분야에서 활발하게 응용이 되고 있는 기술이다. 이러한 전력선 통신을 위한 전송선로는 통신을 위한 정보데이터를 전송하는 기능과 더불어 선로상의 전력 부하들을 위한 전력 공급용으로서의 용도도 가지고 있다. 그러므로 선로상의 부하변동은 다양한 형태의 임 펄스 잡음을 야기 시키고 이러한 임펄스성 잡음은 전송 데이터에 군집에러를 발생시킴으로써 통신성능을 크게 열화 시키는 요인이 되고 있다. 따라서 효율적인 전력선 통신시스템을 위해서는 전력 선로상의 임펄스 잡음의 특성을 명확히 분석하고, 그에 따른 에러제거기법을 적용하는 것이 필수적이라고 할 수 있다. 이러한 관점에서 본 논문에서는 새롭게 가정의 전력 선로에 연결되는 부하들의 동작 및 변동에 따른 임펄스 잡음 특성을 다양한 부하의 유형별로 디지털 하드웨어를 이용하여 실측 및 분류한 후, 새롭게 도출한 임펄스 잡음 모델을 기반으로 순방향 오류정정방식(FEC;Forward Error Correction)인 컨벌루션 부호화(Convolution Coding) 및 인터리빙(Interleaving) 방식을 가미하여 시스템의 비트오율 개선효과를 확인하였다. 본 논문에서 수행된 새로운 실측기반의 임펄스 잡음이 반영된 채널부호화 방식에 의한 성능평가 결과는 향후 홈네트워크기반의 전력선 통신시스템의 실질적인 참고데이터로서 유용하게 활용되리라 기대된다.

• Proceedings of the Korean Information Science Society Conference
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• 2007.10d
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• pp.323-326
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• 2007

홈 네트워크의 산업이 급속도로 성장하고 있지만, 홈 네트워크를 구성하고 있는 가정용 기기들이 다양한 서로 다른 통신 방식과 네트워크, 적용분야 등으로 홈 네트워크 서비스를 제공하는데 문제시되고 있다. 새로군 네트워크 기술과 홈 네트워크 서비스가 등장을 하더라도 일관된 홈 네트워크 서비스의 제공과 수용을 할 수 있도록 위해서는 홈 네트워크를 구성하고 있는 기술의 표준화가 필요하다. OSGi는 게이트웨이상의 서로 다른 기술 또는 타사의 서비스간에도 통신이 가능하게 하는 표준 기술을 제공하고 있다. 본 논문에서는 OSGi가 탑재한 홈 게이트웨이에서의 홈 네트워크 서비스의 요구사항들을 살펴보고, PLC통신 기반에 가정용 제어 기기들과 OSGi의 프레임워크가 탑재한 홈 게이트웨이와의 네트워크를 구현하고, 음성인식과 PDA로 홈 기기들을 제어하는 서비스 제공을 위한 설계와 구현을 하였다.

• Nuclear Engineering and Technology
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• v.46 no.3
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• pp.381-386
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• 2014

A highly reliable safety class controller for NPPs (Nuclear Power Plants) is mandatory as even a minor malfunction can lead to disastrous consequences for people, the environment or the facility. In order to enhance the reliability of a safety class digital controller for NPPs, we employed a diversity approach, in which a PLC-type controller and a PLD-type controller are to be operated in parallel. We built and used structured testbenches based on the classes supported by UVM for functional verification of the PLD-type controller designed for NPPs. We incorporated a UVM register model into the testbenches in order to increase the controllability and the observability of the DUT(Device Under Test). With the increased testability, we could easily verify the datapaths between I/O ports and the register sets of the DUT, otherwise we had to perform black box tests for the datapaths, which is very cumbersome and time consuming. We were also able to perform constrained random verification very easily and systematically. From the study, we confirmed the various advantages of using the UVM register model in verification such as scalability, reusability and interoperability, and set some design guidelines for verification of the NPP controllers.

• Journal of Technologic Dentistry
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• v.36 no.1
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• pp.17-23
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• 2014

Purpose: The purpose of this study was to analyze and compare the relative accuracy of digitized stone models of lower full arch, using two different scanning system. Methods: Replica stone models(N=20) were produced from lower arch acrylic model. Twenty digital models were made with the white light and blue LED($Medit^{(R)}$, Korea) scanner. Two-dimensional distance between the landmarks were measured on the Delcam $CopyCAD^{(R)}$(Delcam plc, UK). Independent samples t-test was applied for comparison of the groups. All statistical analyses were performed using the SPSS software package(Statistical Package for Social Sciences for Windows, version 12.0). Results: The absolute disagreement between measurements made directly on the two different scanner-based dental digital models was 0.02~0.04mm, and was not statistically significant(P>0.05). Conclusion: The precision of the blue LED optical scanner was comparable with the digitization device, and relative accuracy was similar. However, there still is room for improvement and further standardization of dental CAD technologies.