• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2012.10a
• /
• pp.501-504
• /
• 2012

Personal Information Protection Law and Information Communication Network Law is administered from March, 2012 and August, 2012. It is very important to protect and manage the key well so that the third party doesn't know the key. Thus, at present, there increases an importance of Key Management Server. Key Management Server is an appliance type of hardware equipment which can securely store and manage encryption and decryption key. In this paper, we will survey on foreign key management server products and discuss about the necessities of legislation of related law and establishment of policy.

• Tunnel and Underground Space
• /
• v.13 no.1
• /
• pp.33-43
• /
• 2003

Field investigations of the orientations of discontinuity planes inside the borehole for designing the underground rock structures have been depend solely on the borehole image-taking techniques. But, borehole image-taking has to be processed after the completion of drilling operation and also requires the handling of highly expensive apparatus so that practical application is very restricted. In this study Discontinuity Orientation Measurement (DOM) drilling system and discontinuity analysis model RoSA-DOM are developed to acquire the reliable information of rock structure by analyzing the characteristics of joint distribution. DOM drilling system retrieves the rock core on which the reference line of pre-fixed drilling orientation is engraved. Coordinates of three arbitrary points on the joint surface relative to the position of reference line are assessed to determine the orientation of joint plane. The position of joint plane is also allocated by calculating the location of core axis at which joint plane is intersected. Then, the formation of joint set is analyzed by utilizing the clustering algorithm. Total and set spacings are calculated by considering the borehole axis as the scanline. Engineering applicability of in-situ rock mass around the borehole is also estimated by calculating the total and regional RQDs along the borehole axis.

• Particle and aerosol research
• /
• v.9 no.2
• /
• pp.39-50
• /
• 2013

Real-time aerosol measuring instruments have been widely used for the measurement of atmospheric aerosol, diesel particulate matter, or material synthesis. A scanning mobility particle sizer (SMPS) measures the number size distribution of particles using electrical mobility detection technique. An aerodynamic particle sizer (APS) is used to determine the number concentration and the mean aerodynamic diameter of test particles. An electrical low-pressure impactor (ELPI) is a multi-stage impaction device to separate airborne particles into aerodynamic size classes using particle charging and electrical detection techniques. In this study, the performance of these instruments were evaluated to assess their ability to obtain mass concentrations from particle number concentration measurements made as a function of particle size. The effect of determination of particle density on the measurement of mass concentration was investigated for the three instruments.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.50 no.11
• /
• pp.801-807
• /
• 2022

In this paper, we propose an ultra compact S-Band PCM/FM telemetry transmitter. The equipment is compact, so it can be applied to a limited space and capable of stable data transmission was designed and manufactured even with specifications set differently for each operating environment and system. RF direct conversion structure is used for the miniaturization of equipment, an RF transmission board, Power distribution board, and a signal processing board were implemented on a single PCB, so that the function of the transmitter could be performed with a minimum device. According to the target specification, variable output of 1~10W and variable data rate of 390kbps~12.5Mbps is possible in S-Band(2,200~2,400MHz) without degradation of performance. To verify the performance of the equipment, the RF performance test and BER measurement test were performed after the equipment was manufactured. It was confirmed that the OBW, null-to-null bandwidth, 1st IMD, Spurious emission, Phase noise specification of the PCM/FM modulated signal which is presented by the IRIG standard were satisfied, and we can confirm the data received using the transmitter inspection equipment were transmitted normally without distortion.

• 한국신재생에너지학회:학술대회논문집
• /
• 2005.06a
• /
• pp.172-176
• /
• 2005

Phase Lacked Loop(PLL)은 분산전원을 계통연계시 동기설정을 위해 중요한 장비이다. 이러한 동기설정은 Point of Common Coupling(PCC)에서 계통 전압을 검출하여 크기와 위상을 동일하게 설정하여 전력변환장치에서 전력을 출력한다. 일반적으로 PCC에서 계통전압을 검출하였을 때 고조파, 상간불평형은 전력변환장치 출력 왜곡을 야기 시킨다. 본 논문에서는 이러한 출력왜곡을 감소시키기 위한 3상 PLL을 모델링하여, 그 제어 성능을 시뮬레이션을 통해 확인하였다.

• Proceedings of the Korean Nuclear Society Conference
• /
• 1995.05a
• /
• pp.1054-1059
• /
• 1995

국제원자력기구에서는 현재 적용되고 있는 보장조치(Safeguards) 방법을 보다 효과적이고 효율적으로 적용하기 위하여 1993년부터 'Program 93+2'라는 사업을 수행하고 있다. 이중 하나의 과제로 수행되고 있는 구역 보장조치는 기존의 보장조치 개념이 하나의 시설을 대상(Facility-Oriented Safeguards)으로 개발된 것과는 달리 동일한 범주의 핵물질을 취급하는 여러 개의 시설을 하나의 가상적인 구역(Fuel Cycle-Oriented Safeguards)으로 설정하여 보장조치를 적용하는 개념으로, 보다 강화된 사찰 활동에 의하여 보장조치 신뢰도를 향상시키면서 사찰 횟수 및 사찰량은 절감되고 있다. 우리나라는 한국원자력연구소의 중수로핵연료 가공시설과 월성 1호기를 천연우라늄 구역(Natural Uranium Zone)으로, 한국원전연료(주)의 경수로핵연료 가공시설과 국내의 모든 경수로를 저농축우라늄 구역(Low Enriched Uranium Zone)으로 설정하여 성공적으로 구역 보장조치를 적용하고 있다. 그러나 이러한 구역 보장조치의 적용에는 원자력산업 체제의 단순화와 같은 제약조건이 따른다. 앞으로 우리나라에서는 현재 적용되고 있는 구역 보장조치 방법이 보다 효율적으로 운영되고 시설 운영에 대한 방해를 최소화시키는 방안을 고려하여야 하며 이에 는 가공시설에서의 생산 및 수송 일정을 발전소 운영 및 사찰 일정과 적절히 조화시키는 방법, 가공시설에서 검증된 핵연료에 대하여 적절한 감시 및 봉인 장비를 적용하는 방법, 현재의 구역 이외의 시설 또는 핵물질에 새로운 구역을 설정, 적용하는 방안 등을 고려할 수 있다.

• Convergence Security Journal
• /
• v.6 no.4
• /
• pp.67-73
• /
• 2006

The method which research a standardization from real time cyber threat is finding the suspicious indication above the attack against cyber space include internet worm, virus and hacking using analysis the event of each security system through correlation with the critical point, and draft a general standardization plan through statistical analysis of this evaluation result. It means that becomes the basis which constructs the effective cyber attack response system. Especially at the time of security accident occurrence, It overcomes the problem of existing security system through a definition of the event of security system and traffic volume and a concretize of database input method, and propose the standardization plan which is the cornerstone real time response and early warning system. a general standardization plan of this paper summarizes that put out of threat index, threat rating through adding this index and the package of early warning process, output a basis of cyber threat index calculation.

• Economic and Environmental Geology
• /
• v.39 no.4 s.179
• /
• pp.417-426
• /
• 2006

Data acquisition is as important as data processing and interpretation in the field of marine geophysical exploration. Marine geophysicist, however, may not have enough information in this field because data acquisition method has been mainly developed by the commercial companies manufacturing the equipment. Therefore, the purpose of this paper is to introduce the general data acquisition method and information to help to construct the systematic and effective survey plan. When a survey plan is set up, the most important thing is to select the seismic equipment based on required penetration depth and resolution, and then construct the survey line intervals. Although a line interval varies from the research purposes, it should be narrower than the expected subsurface structures. Also, if 100% coverage of multibeam data is required, line intervals need to be adjusted based on the equipment characteristics. In case of merging with the preexisting dataset like bathymetry, gravity and magnetic, cross-over errors occurred at the each cross point should be removed to avoid any kinds of misinterpretation.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.16 no.1
• /
• pp.3-7
• /
• 2012

Purpose : In myocardial perfusion SPECT, the type of orbit (circular vs. body contouring) that affect the image quality is still on the debate. Presently in the nuclear medicine field, the body contouring orbit acquisition is widely used to improve the image quality on the myocardial perfusion SPECT. But in case of body contouring acquisition using the vertical method with dual detect machine, there is a tendency of increasing the radius. In this research, we compared body contouring orbit acquisition with circular orbit acquisition, so we suggest ideal method that reduces the radius for improving image quality. Materials and Methods : Phantom and clinical studies were performed. The anthropomorphic torso phantom was made on equally with counts from patient's body. The study was performed under six different conditions. To compare image quality according to the radius, we increased radius sequentially per step during circular orbit acquisition. On the other hand, sensors that protect a collision and reduce the radius automatically were used to acquire image during body contouring orbit acquisition. So we compared FWHM value of apex. In clinical studies, we analyzed the 40 patients who were examined by Tl-201 gated myocardial perfusion SPECT in department of nuclear medicine at Asan Medical Center in August 2011. To acknowledge the differences according to the radius, we acquired the results two times using circular orbit acquisition and body contouring orbit acquisition. Results : In phantom study, we analyzed that increase of radius resulted in changes of FWHM value. It was 5.41, 6.24, 6.33, 6.42, 6.93 mm. On the other hand, using the body contouring orbit acquisition, FWHM value was 6.23 mm. In clinical study, difference of average radius between two methods was 2.5 cm (circular orbit acquisition was more close to patients). Conclusion : Through the experiments using Anthropomorphic torso phantom and patients data, we found that FWHM value of circular orbit acquisition was lower than body contouring orbit acquisition. As a result, if the difference of average radius exists approximately 3 cm, circular orbit type acquisition is better than body contouring type acquisition. But clinical investigation is only aimed to average radius, so it needs more investigation in comparison of patient's image.

• Journal of Practical Engineering Education
• /
• v.16 no.2
• /
• pp.179-184
• /
• 2024

Printed circuit boards (PCBs) are a key component widely used in the production of electronic products, and not only quantitative growth but also qualitative developments such as integration cannot be ignored. Wave soldering equipment is commonly used equipment at manufacturing sites, but it is impossible to configure a dedicated equipment environment suitable for each PCB specification during the preliminary research and prototype development stage. It is neither suitable for development within limited time line nor manufacturing various product groups because only equipment setting conditions can be changed within a given time. In this study, we introduce a case of introducing a PCB pallet to enable selection of optimal process conditions within the limited environment described above. In addition, by presenting a discriminant that can determine in advance whether production is possible with current general-purpose equipment, it is expected that problems that may arise due to limitations in the general-purpose wave soldering equipment environment can be identified and resolved in advance. Ultimately, this palette makes it possible to shorten the development period and improve productivity.