• Review of KIISC
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• v.31 no.1
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• pp.57-64
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• 2021

기존의 공개키 암호가 양자 알고리즘에 취약함이 밝혀지고 양자컴퓨터의 개발이 현실화됨에 따라 NIST는 미연방표준 양자 내성 암호 공모전을 실시하고 있다. FALCON은 공모전 Round 3까지 통과한 전자서명 알고리즘으로 서명 및 검증 속도가 빠르고 공개키 및 서명 길이가 짧다는 장점이 있다. 하지만 FALCON은 부동소수점 연산 등 특별한 구조로 설계되어 새로운 형태의 부채널 공격이 존재할 수 있다. 본 논문에서는 FALCON에 대한 세 가지 전력 분석 공격의 가능성을 제시한다. 또한 주어진 공격을 활용하여 개인키를 복원하는 방안에 대해서 제시한다.

• The KIPS Transactions:PartB
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• v.13B no.4 s.107
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• pp.429-438
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• 2006

Neural Networks(NNs) are applied for solving a wide variety of nonlinear problems in several areas, such as image processing, pattern recognition etc. Although NN can be simulated by using software, many potential NN applications required real-time processing. Thus they need to be implemented as hardware. The hardware implementation of multi-layer perceptrons(MLPs) in several kind of NNs usually uses a fixed-point arithmetic due to a simple logic operation and a shorter processing time compared to the floating-point arithmetic. However, the fixed-point arithmetic-based MLP has a drawback which is not able to apply the MLP software that use floating-point arithmetic. We propose a design method for MLPs which has the floating-point arithmetic-based fully-pipelining architecture. It has a processing speed that is proportional to the number of the hidden nodes. The number of input and output nodes of MLPs are generally constrained by given problems, but the number of hidden nodes can be optimized by user experiences. Thus our design method is using optimized number of hidden nodes in order to improve the processing speed, especially in field of a repeated processing such as image processing, pattern recognition, etc.

• Venture DIGEST
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• s.24
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• pp.4-5
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• 2003

월드컵 4강의 꿈(★)을 이뤄냈던 대한민국 축구. 그 중심에는 자랑스런 24인의 태극전사가 있었다. 그리고 한마음으로 목이 터져라 응원전을 펼친 4000만 국민이 있었다. 하지만 우리의 기억 속에 우뚝 자리한 사람은 누가 뭐라고 해도 거스 히딩크 감독일 것이다.그는 선수 개개인의 능력을 철저히 분석하고 조련하여 여러 포지션을 소화낼 수 있는 멀티플레이어를 만들어냄으로써 월드컵 4강의 신화를 창조해 낼 수 있었다. 하지만 멀티플레이어는 푸른 그라운드뿐 아니라 벤처업계도 존재한다. 1994년 국내 최초로 컴퓨터와 전화를 통합시킨 CTI(Computer Telephony Integration)를 도입하여 국내 정보통신 부가서비스 분야에서 폭발적인 성장을 이끌면서 부동의 업계 1위를 고수하고 있는 콜센터 전문기업 로커스의 김형순 대표, 그가 바로 멀티플레이형 벤처기업인이다. 무역업을 시작으로 사업에 뛰어든 김 대표는 팩스 뉴스 자동검색 서비스, 통신솔루션 그리고 엔트테인먼트에 이르기까지 그야말로 다재다능한 능력을 보여준 멀티플레이어 벤처인이다.

• Journal of the Korean Chemical Society
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• v.60 no.6
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• pp.402-409
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• 2016

Thin films of lead sulfide colloidal quantum dots (CQDs) of 2.8 nm in diameter are fabricated and their surfaces are passivated by 3-mercaptopropionic acid (MPA) ligand or hybrid type ($MPA+CdCl_2$) ligand, respectively. The changes in valence band electronic structure and atomic composition of each PbS CQD film upon post-treatment such as air, N2 annealing or UV/Ozone have been studied by photoelectron spectroscopy. The air annealing makes the CQD fermi level to move toward the valence band leading to "p-type doping" regardless of ligand type. The UV/Ozone post-treatment generates $Pb(OH)_2$, $PbSO_x$ and PbO on both CQD surfaces. But the amount of the PbO has been reduced in hybrid type ligand case, especially. That is probably because the extra Pb cations in (111) surface are additionally passivated by $Cl_2$ ligand, which limits the reaction between the Pb cation and ozone.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.4
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• pp.421-428
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• 2012

In this study, the effects of surface oxide film formation on the fatigue behavior of 7075-T6 aluminum alloy were analyzed in terms of the corrosion time of the alloy. The aluminum material used is known to have high corrosion resistance due to the passivation phenomenon that prevents corrosion. Aluminum alloys have been widely used in various industrial applications such as aircraft component manufacturing because of their lighter weight and higher strength than other materials. Therefore, studies on the fatigue behavior of materials and passivation properties that prevent corrosion are required. The fatigue behavior in terms of the corrosion time was analyzed by using a four-pointing bending machine, and the surface corrosion level of the aluminum material in terms of the corrosion time was estimated by measuring the surface roughness. In addition, fractographic analysis was performed and the oxide films formed on the material surface were studied by scanning electron microscopy (SEM). The results indicated that corrosion actively progressed for four weeks during the initial corrosion phase, the fatigue life significantly decreased, and the surface roughness increased. However, after four weeks, the corrosion reaction tended to slow down due to the passivation phenomenon of the material. Therefore, on the basis of SEM analysis results, it was concluded that the growth of the surface oxide film was reduced after four weeks and then the oxide film on the material surface served as a protection layer and prevented further corrosion.

• MISULJARYO - National Museum of Korea Art Journal
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• v.101
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• pp.48-65
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• 2022

Three Japanese Buddhist scuptures of Daehyusa temple in Gimcheon, Gyeongsangbuk-do province(慶尙北道) are enshrined in the main hall(本堂) of Henjoin temple in Daegu, an annex temple built by the Chisan School(智山派) of Shingi Shingon sect(新義眞言宗) in Daegu around 1910 when the Japanese colonial period began. The following statues are believed to have been made around this time: the Statue of Kobo daishi(弘法大師像), which is the figure of monk Kukai(空海, 774-835), the founder of the Shingon sect(眞言宗) of Japan, and the Statue of Dainichi nyorai(大日如來像) and the Statue of Fudo myo-o(不動明王像), which are notable sculptures representing the thought and belief of the Shingon sect. Most statues identified of Dainichi nyorai, Kobo daishi, and Fudo myo-o from the Japanese colonial period thus far are rock-carved statues or stone statues. The statues of Daehyusa temple are noteworthy in that they are the first discovered Japanese Buddhist sculptures made of wood, known to have been enshrined in Japanese temples. Furthermore, they are valuable sources that can provide clues to the religious atmosphere of the temples of Chisan School of Shingi Shingon sect at the time. Although these statues have formative features that partially reflect modern aesthetics, their iconographic origins date back to the Heian period(平安時代, 794-1185). In other words, the Statue of Dainichi nyorai inherits the religious tradition of the Statue of Dainichi nyorai, which was created by monk Kakuban(覺鑁, 1095-1143), the founder of the Shingi Shingon sect. The Statue of Kobo daishi follows the Shinnyo Shinno(眞如親王) style founded by Monk-Imperial Prince Shinnyo who was a disciple of monk Kukai. The Statue of Fudo myo-o manifests the Genjo(玄祖) style among the statues of Fudo myo-o. Although not much is known about how the statues were enshrined in the Henjoin temple in Daegu during the Japanese colonial period, it is very likely that these statues were created as Shingi Shingon sect's statue of three-wheeled body(三輪身). That is, it is estimated that the Statue of Dainichi nyorai, Statue of Kobo daishi, and Statue of Fudo myo-o have the characteristics of the body of self-nature chakra(自性輪身), the body of great dharma chakra(正法輪身), and the body of order chakra(敎令輪身), respectively. The fact that the statue of three-wheeled body was established in the Shingon sect in Japan by monk Kakuban also lends credence to this possibility. It is thought that people who came to the Henjoin temple in Daegu worshiped the statue of three-wheeled body to understand the teachings of the Dainichi nyorai. Although it is the case of Sildalsa Temple (悉達寺, the successor of Henjoin temple in Daegu) in the first half of the 1950s, the main hall includes features that reinforce the idea that the tradition of Kobo daisi faith(弘法大師信仰) is passed on. To illustrate, the human skeletal remains in the main hall of Sildalsa Temple reflect Koyasan(高野山)'s tradition in laying ashes to rest, which has been popular in conjunction with the Kobo daishi faith in Japan since the 11th century.

• Proceedings of the Korea Society for Industrial Systems Conference
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• 2008.10b
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• pp.269-277
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• 2008

지식기반경제에서는 기식을 창출하거나 활용하는 능력이 기업의 경쟁력을 결정하는 중요한 요소가 될 뿐만 아니라 국가적 경쟁우위의 기본이 된다. 산업경제에서 지식기반경제로의 이행이 가속화됨에 따라 부동 산 및 설비 등 유형자산 보다는 노하우, 특허권 등의 무형자산이 기업 경쟁력에 미치는 영향이 더욱 커지고 있다. 유형자산과 마찬가지로 기업이 소유하고 있는 무형자산인 특허권의 합리적 가치평가도 중요하다. 왜냐하면 특허 가치의 정확한 평가는 기술 거래 시장의 활성화를 가져올 수 있고 또한 기업의 특허전략 수립에 필수적이기 때문이다. 하지만 유형자산과는 달리 무형자사인 특허권의 정확한 가치평가는 매우 어려운 것으로 알려져 있다. 본 연구의 목적은 특허가치 평가에 영향을 미치는 요소들을 살펴보고자 함에 있으며, 그 중에서도 제품 특성에 초점을 맞추었다.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.05b
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• pp.98-103
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• 1997

원전 증기 발생기 재료로 사용되는 Alloy 600의 내부식성 향상을 위하여 레이저 범을 이용한 레이저 표면합금화(Laser Surface Alloying, LSA) 방법을 이용, 표면에 약 200$\mu\textrm{m}$ 두께의 합금층을 형성시켰다. 첨가한 원소는 크롬 또는 크롬과 니켈의 혼합체를 사용하였으며 첨가법으로는 도금과 용사를 이용하였다. 용사법으로 만든 LSA 시편의 특성과 문제점에 대해 고찰하고 이러한 문제점을 해결하는 방법으로 크롬 도금법을 택하였다. 이들 결과를 레이저 처리를 하지 않은 시편들과 비교하여 부식 거동을 분석하였다. 분석 결과 LSA 시편의 경우 As-received 시편, 레이저 표면 용융(LSM) 들과 비교해 아주 우수한 내부식성을 가졌으며 입계 내부식성도 크게 증가하였다. 이는 크롬 첨가로 인해 크롬의 농도가 많아져 부동태 피막의 형성이 쉬워졌기 때문으로 해석되었다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.2A
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• pp.188-194
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• 2007

In order to become ubiquitous world, the compatibility of wireless machines has become the significant characteristic of a communication terminal. Thus, SDR is the most necessary technology and standard. However, among the environment which has different communication protocol, it's difficult to make a terminal with only hardware using ASIC or SoC. This paper suggests the processor that can accelerate several communication protocol. It can be connected with main-processor, and it is specialized PHY layer of network The C-program that is modeled with the wireless protocol IEEE802.11a and IEEE802.11b which are based on widely used modulation way; OFDM and CDM is compiled with ARM cross compiler and done simulation and profiling with Simplescalar-Arm version. The result of profiling, most operations were Viterbi operations and complex floating point operations. According to this result we suggested a co-processor which can accelerate Viterbi operations and complex floating point operations and added instructions. These instructions are simulated with Simplescalar-Arm version. The result of this simulation, comparing with computing only one ARM core, the operations of Viterbi improved as fast as 4.5 times. And the operations of complex floating point improved as fast as twice. The operations of IEEE802.11a are 3 times faster, and the operations of IEEE802.11b are 1.5 times faster.

• Applied Chemistry for Engineering
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• v.32 no.6
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• pp.664-670
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• 2021

Stainless steel was applied as bipolar plate (BP) of polymer electrolyte membrane fuel cell (PEMFC) due to high mechanical strength, electrical conductivity, and good machinability. However, stainless steel was corroded and increased contact resistance resulting PEMFC performance decrease. Although the corrosion resistance could be improved by surface treatment such as noble metal coating, there is a disadvantage of cost increase. The stainless steel corrosion behavior and passive layer influence on PEMFC performance should be studied to improve durability and economics of metal bipolar plate. In this study, SUS316L bipolar plate of 25 cm² active area was manufactured, and experiments were conducted for corrosion behavior at an anode and cathode. The influence of SUS316L BP corrosion on fuel cell performance was measured using the polarization curve, impedance, and contact resistance. The metal ion concentration in drained water was analyzed during fuel cell operation with SUS316L BP. It was confirmed that the corrosion occurs more severely at the anode than at the cathode for SUS316L BP. The contact resistance was increased due to the passivation of SUS316L during fuel cell operation, and metal ions continuously dissolved even after the passive layer formation.