• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.43 no.2 s.308
• /
• pp.1-11
• /
• 2006

In this paper, we propose a new register file architecture called the Register File Extension for Multi-words or Long-word Operation (RFEMLO) to accelerate both symmetric and asymmetric cryptographic algorithms. Based on the idea that most of cryptographic algorithms heavily use multi-words or long-word operations, RFEMLO allows multiple contiguous registers to be specified as a single operand. Thus, a single instruction can specify a SIMD-style multi-word operation or a long-word operation. RFEMLO can be applied to general purpose processors by adding instruction set for multi-words or long-word operands and functional units for additional instruction set. To evaluate the performance of RFEMLO, we use Simplescalar/ARM 3.0 (with gcc 2.95.2) and run detailed simulations on various symmetric and asymmetric cryptographic algorithms. By applying RFEMLO, we could get maximum 62% and 70% reductions in the total instruction count of symmetric and asymmetric cryptographic algorithms respectively. Also, performance results show that a speedup of 1.4 to 2.6 can be obtained in symmetric cryptographic algorithms and a speedup of 2.5 to 3.3 can be obtained for asymmetric cryptographic algorithms when we apply RFEMLO to a processor with an in-order pipeline. We also found that RFEMLO can effectively improve the performance of these cryptographic algorithms with much less cost compared to issue-width increase available in Superscalar implementations. Moreover, the RFEMLO can also be applied to Superscalar processor, leading to additional 83% and 138% performance gain in symmetric and asymmetric cryptographic algorithms.

• Journal of the Korea Society of Computer and Information
• /
• v.17 no.12
• /
• pp.31-39
• /
• 2012

In this paper, we propose a microprocessor-based automatic voltage regulator(AVR) to reduce consumers' electric energy consumption and to help controlling peak demanding power. Hybrid Switching Automatic Voltage Regulator (HS-AVR) consist of a toroidal core, several tap control switches, display and command control parts. The coil forms an autotransformer which has a serial main winding and four parallel auxiliary windings. It controls the output voltage by changing the combination of the coils and the switches. Relays are adopted as the link switches of the coils to minimize the loss. To make connecting and disconnecting time accurate, relays of the circuit have parallel TRIACs. A software phase locked loop(PLL) has been used to synchronize the timings of the switches to the voltage waveform. The software PLL informs the input voltage zero-crossing and positive/negative peak timing. The traditional voltage transformers and AVRs have a disadvantage of having a large mandatory capacity to accommodate maximum inrush current to avoid the switch contact damage. But we propose a suitable AVR for every purpose in smart grid with reduced size and increased efficiency.

• Journal of Korean Society of Disaster and Security
• /
• v.16 no.2
• /
• pp.15-32
• /
• 2023

There are some difficulties such as safety problem and need of manpower in measuring discharge by submerging the instruments because of many floating debris and very fast flow in the river during the flood season. As an alternative, microwave water surface current meters have been increasingly used these days, which are easy to measure the discharge in the field without contacting the water surface directly. But it is also hard to apply the method in the sudden and rapidly changing field conditions. Therefore, the estimation of the discharge using the surface velocity in flood conditions requires a theoretical and economical approach. In this study, the measurements from microwave water surface current meter and rating curve were collected and then analyzed by the discharge estimation method using the surface velocity. Generally, the measured and converted discharge are analyzed to be similar in all methods at a hydraulic radius of 3 m or over or a mean velocity of 2 ㎧ or more. Besides, the study computed the discharge by the index velocity method and the velocity profile method with the maximum surface velocity in the section where the maximum velocity occurs at the high water level range of the rating curve among the target locations. As a result, the mean relative error with the converted discharge was within 10%. That is, in flood season, the discharge estimation method using one maximum surface velocity measurement, index velocity method, and velocity profile method can be applied to develop high-level extrapolation, therefore, it is judged that the reliability for the range of extrapolation estimation could be improved. Therefore, the discharge estimation method using the surface velocity is expected to become a fast and efficient discharge measurement method during the flood season.

• KDI Journal of Economic Policy
• /
• v.27 no.1
• /
• pp.81-122
• /
• 2005

The paper aims to establish the characteristics of the Korean firms' R&D investment and to estimate the private rate of return to R&D investment. For the empirical analysis, a balanced panel data is constructed with 695 firms on 8 year observations. The panel data enables to characterize R&D investment of the Korean firms, which is mostly conformed to the 'stylized facts' of R&D investment that found in the previous studies on foreign firms. Klette model was used to estimate the private rate of return on R&D investment and depreciation rate of R&D capital. The paper estimates that the rate of return on R&D investment is 10.5% on average or 16.4% on median for the whole industry whereas manufacturing firms show 10.4% on average or 16.4% on median. The depreciation rate was estimated about 32.9% for whole industry, where it ranges from the minimum 11.6% for metal industry and 49.5% for services. The median estimate of the rate of return for R&D investment of Korean firms is roughly two times higher than real interest rates for the same period, which implies that R&D investment allows sizable rent in addition to the opportunity cost of capital investment.

• 한국신재생에너지학회:학술대회논문집
• /
• 2011.05a
• /
• pp.155-155
• /
• 2011

용융탄산염 연료전지(MCFC)는 $650^{\circ}C$에서 작동하는 고온형 연료전지 시스템이다. 이 시스템은 천연가스 등을 개질하여 생산된 수소를 바로 전기로 생산할 수 있는 시스템으로 열효율이 높으며, 현재 대체 발전시스템으로 각광을 받고 있다. MCFC는 개질방식에 따라 내부개질 방식과 외부개질 방식이 있다. 내부개질 방식은 수소를 생산하는 개질기가 스택내부에 장착된 형식으로 천연가스를 스택내부에서 개질하여 바로 전기를 생산하는 방식이다. 이 내부개질반응에 사용되는 촉매로는 알루미나에 고함량 (약 50 wt.%)으로 담지된 니켈(Ni) 계열촉매이 주로 쓰이고 있다. 이 고함량으로 담지된 촉매는 대부분 높은 활성을 보인다. 비교적 낮은 온도 운전조건 (약 $580{\sim}620^{\circ}C$)을 가지는 MCFC 내부개질에 적용하기 위해서는 활성점인 니켈을 최대한 담지체에 고르게 분산 시켜야한다. 이를 위해서 MgO를 이용하여 촉매의 활성점을 높게 분산시키는 연구를 진행 하였다. 촉매를 제조하는 방법으로 요소(urea)를 이용한 균일용액침전법을 이용하였다. 니켈함량은 50 wt.%로 고정을 한 다음, MgO 양과 $Al_2O_3$ 양을 각각 0 ~ 45 wt.%와 5 ~ 50 wt.%로 조절하면서 촉매를 제조하여 그 특성들을 분석하였다. 물성을 비교하기 위해서, X-선 회절분석 (XRD) 및 TPR, 물리화학흡착 실험을 하였다. 촉매의 활성을 살펴보기 위해서, fresh 상태 및 피독 상태에서 메탄수증기 개질활성 실험을 실시하였다. MgO 함량이 없거나 적은 촉매에서는 높은 BET surface area와 작은 NiO, metallic Ni 결정 크기가 나타났다. 반면 MgO 함량이 높은 촉매에서 낮은 BET surface area와 비교적 큰 NiO, metallic Ni 결정 크기가 나타났다. 또한 XRD 분석에서 MgO 함량이 증가할 수 록 MgO 결정 피크가 명확히 나타났으며, $MgAl_2O_4$ 피크는 나타나지 않았다. TPR 분석에서 촉매들의 환원 피크를 측정한 결과, 저함량의 MgO를 포함한 촉매는 $700^{\circ}C$ 부근에 환원 피크가 관찰되었고 MgO가 고함량인 촉매는 환원 피크가 $400^{\circ}C$ 부근에서 관찰되었다. 촉매의 초기 fresh 상태에서의 활성은 고함량 MgO를 포함한 Ni-90M10A 샘플을 제외하고 모든 촉매가 거의 비슷하게 나타났다. 그러나 $K_2CO_3$ 피독 상태에서는 MgO 함량이 증가할 수 록 활성이 좋지 않았음을 알 수 있었다. 따라서 MgO가 소량 포함된 촉매의 경우 fresh 상태에서는 우수한 물성과 활성을 보이지만, 피독상태에서는 MgO가 포함되지 않은 Ni-$Al_2O_3$ 촉매가 우수한 활성을 보였다.

• Proceedings of the Korean Society of Organic Agriculture Conference
• /
• 2001.10a
• /
• pp.207-218
• /
• 2001

미국의 콘벨트와 같이 곡물을 집약적으로 재배하는 지역에서 관행생산으로부터 유기적 생산으로 전환할 때 문제가 되는 것은 어떻게 하면 작물윤작을 더 많은 이익이 나올 수 있도록 선택하고 관리하는가 하는 점이다. 곡물생산을 중단하고 사료와 녹비작물을 재배하는데 드는 기회비용은 상당하다. 많은 유기농업 연구자, 학자들은 가축사육을 농장에 도입하여 다양화와 노동력 활용도를 높일 필요가 있음을 강조하고 있다. 가축 역시 곡물생산량이 줄어드는 것을 보완해줄 정도로 곡물 및 사료작물의 가치를 늘려 추며, 곡물생산에 쓰여진 양분을 퇴비를 통해 재활용할 수 있게 해 준다. 곡물 집약재배 지역에서 유기농가는 양돈이 경종체계에 자연스럽게 들어맞는 것으로 생각해 볼 필요가 있다. 돼지는 곡물과 사료작물 모두에 가치를 증대시켜 줄 수 있는 아주 효율적이고 적용이 쉬운 가축이다. 그다지 많지는 않지만 유기적, 지속가능한 양돈 생산에 관해서는 문헌이 좀 있다. 그러나 유기농가로 하여금 유기양돈 생산을 하도록, 그리고 유통의 방법을 어떻게 할 것인가 결정을 내리는데 도움을 줄 수 있는 그런 비교적 구체적인 정보는 그리 많지 않다. 이 글의 주요 초점은 미국 중부지방에서의 유기축산 생산(주로 돼지)에 관한 배경과, 시장의 추세, 인구적 특성, 미국의 기준들에 비추어 생산과 유통에 관한 결정 및 고려사항들에 대한 개관을 제시해 보는 일이다. 농장 수준에서 의사결정은 토지, 노동, 금융과 사회적 자본과 같은 자원을 각종 기회와 더불어 고려하여 이루어져야 한다. 이러한 결정은 모두 농장 차원을 넘어 각종 기준과 시장에서의 세력들의 맥락을 보고 이루어져야 한다. 각 개인의 수준에서는 농업인 역시 유기 흑은 환경친화적 농업에 관한 확신, 바꾸어 보겠다는 결심, 생활양식과 가족에 대한 영향, 그리고 농업인과 가족 경영에 대한 계획의 지평이라고 하는 범위 내에서의 유기적 방식으로의 전환에 관하여 결정을 내려야 한다.aotic motion)의 해석도 가능하다. 이 글에서는 비선형 진동해석을 위한 정규모드 동역학에 대한 연구동향 및 기본 이론을 살펴 보았고, 그 적용 예를 통하여 실험결과와 비교 고찰 함으로써 정규모드 동역학의 적용성을 서술하여 보았다. 선형이론으로 이해하기 어려운 현상들에 대하여는 비선형의 관점에서 새롭게 접근하 려는 노력이 필요하며 비선형 이론에 대한 연구가 지속적으로 진행되어야 한다. 진행되어야 한다.VA코드를 사용하여 흡기포트와 연소실 그리고 밸브의 움직임을 동시에 고려한 수치해석을 도입하였다. 하지만 이들이 밸브의 운동을 고려하기 위해 사용한 이동격자는 격자점은 시간에 따라 변화하지만 그 격자의 수가 일정하게 유지되어 있어서 밸브의 완전개폐를 해석할 수가 없다. 강희정[6]은 단일 실린더와 단일 배기밸브를 갖는 문제로 단순화하여 피스톤과 밸브의 움직임을 고려하므로써 배기행정 후 소음이 어떻게 전파해 나가는가를 연구하였다. 본 연구에서도 최소밸브간격과 최대밸브간격 사이에서만 계산이 가능하나 흡기의 경우는 밸브가 닫힐 때 생기는 압력파가 중요하므로 실린더와 밸브사이에 벽면조건을 주어 밸브의 개폐를 모사하였다.술을 보유하고자 한다. 이용한 해마의 부피측정은 해마경화증 환자의 진단에 있어 육안적인 MR 진단이 어려운 제한된 경우에만 실제적 도움을 줄 수 있는 보조적인 방법으로 생각된다.ofile whereas relaxivity at high field is not affected by τS. On the other hand, the change in τV does not affect low field profile but strongly in fluences on both inflection fie이 and the maximum relaxivity value. The results shows a fluences on both inflection field and the maximu

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.21 no.7
• /
• pp.496-503
• /
• 2020

The regeneration of Incheon Inner Port is a recent, representative case of conflict related to urban policies. This study aimed to analyze the conflicts that have arisen during the urban regeneration process. This study was a qualitative study, and the conflict management strategy was derived by analyzing the conflict process, subject, and content. The results of the analysis are as follows. First, central governmental agencies have proposed a clear plan that is mainly focused on the port redevelopment project through the participation of private sector businesses. Second, Incheon is pursuing a new vision called "Creative City" with specific urban regeneration. Third, the Incheon Port Authority is required to maximize the efficiency of the regeneration projects. Fourth, organizations such as port logistics companies and port trade unions are demanding the use of port space. Fifth, local residents and civic groups insist that the entire Inner Harbor should be returned to the citizens. Therefore, the establishment of city planning and administrative guidelines is necessary to manage Incheon Inner Harbor and surrounding areas in a desirable manner in order to develop a regeneration philosophy for Incheon Inner Harbor. Furthermore, the establishment of cooperative governance is required for the participation of various stakeholders.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.45 no.2
• /
• pp.10-20
• /
• 2008

Generally, to acquire an HDR image, many images that cover the entire dynamic range of the scene with different exposure times are required, then these images are fused into one HDR image. This paper proposes an efficient method for the HDR image acquisition with small number of images. First, we estimated scenic dynamic range using two images with different exposure times. These two images contain the upper and lower limit of the scenic dynamic range. Independently of the scene, according to varied exposure times, similar characteristics for both the maximum gray levels in images that include the upper limit and the minimum gray levels in images that include the lower limit are identified. After modeling these characteristics, the scenic dynamic range is estimated using the modeling results. This estimated scenic dynamic range is then used to select the proper exposure times for the acquisition of an HDR image. We selected only three proper exposure times because entire dynamic range of the cameras could be covered by three dynamic range of the cameras with different exposure times. To evaluate the error of the HDR image, experiments using virtual digital camera images were carried out. For several test images, the error of the HDR image using proposed method was comparable to that of the HDR image which utilize more than ten images for the HDR image acquisition.

• KIPS Transactions on Software and Data Engineering
• /
• v.12 no.10
• /
• pp.461-470
• /
• 2023

While speech animation generation employing deep learning has been actively researched for English, there has been no prior work for Korean. Given the fact, this paper for the very first time employs supervised deep learning to generate Korean speech animation. By doing so, we find out the significant effect of deep learning being able to make speech animation research come down to speech recognition research which is the predominating technique. Also, we study the way to make best use of the effect for Korean speech animation generation. The effect can contribute to efficiently and efficaciously revitalizing the recently inactive Korean speech animation research, by clarifying the top priority research target. This paper performs this process: (i) it chooses blendshape animation technique, (ii) implements the deep-learning model in the master-servant pipeline of the automatic speech recognition (ASR) module and the facial action coding (FAC) module, (iii) makes Korean speech facial motion capture dataset, (iv) prepares two comparison deep learning models (one model adopts the English ASR module, the other model adopts the Korean ASR module, however both models adopt the same basic structure for their FAC modules), and (v) train the FAC modules of both models dependently on their ASR modules. The user study demonstrates that the model which adopts the Korean ASR module and dependently trains its FAC module (getting 4.2/5.0 points) generates decisively much more natural Korean speech animations than the model which adopts the English ASR module and dependently trains its FAC module (getting 2.7/5.0 points). The result confirms the aforementioned effect showing that the quality of the Korean speech animation comes down to the accuracy of Korean ASR.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.47 no.4
• /
• pp.63-72
• /
• 2010

This paper proposes a new authentication protocol for the LR-WPAN. In order to guarantee the reliability and safety of a protocol, this protocol uses the hierarchical authentication approach. In addition, in order to reduce the impact of the denial of service attack, the proposed protocol performs the authentication between a parent router and a joiner device prior to the authentication between a trust center and the joiner device. Moreover, this protocol reduces the authentication delay by decreasing the number of message exchanges during authentication procedure. This paper evaluates the safety of the proposed protocol by the security analysis and reliability of the proposed protocol by the GNY analysis. This paper also compares the number of message exchanges of the ZigBee authentication protocol and the proposed protocol when denial of service attack occurs to evaluate the resistance of the proposed protocol against the denial of service attack. We also analyze the delay for authentication of the joiner device through the implementation of both protocols. Those results show that the proposed protocol effectively protects networks from the denial of service attack and reduces the time for authenticating the joiner device up to maximum 30% as the number of hops increases.