• Nuclear Engineering and Technology
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• 제55권9호
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• pp.3213-3228
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• 2023

As an important part of the digital reactor, the pin-by-pin wise fine coupling calculation is a research hotspot in the field of nuclear engineering in recent years. It provides more precise and realistic simulation results for reactor design, operation and safety evaluation. CORCA-K a nodal code is redeveloped as a robust pin-by-pin wise neutronics and thermal-hydraulic coupled calculation code for pressurized water reactor (PWR) core. The nodal green's function method (NGFM) is used to solve the three-dimensional space-time neutron dynamics equation, and the single-phase single channel model and one-dimensional heat conduction model are used to solve the fluid field and fuel temperature field. The mesh scale of reactor core simulation is raised from the nodal-wise to the pin-wise. It is verified by two benchmarks: NEACRP 3D PWR and PWR MOX/UO₂. The results show that: 1) the pin-by-pin wise coupling calculation system has good accuracy and can accurately simulate the key parameters in steady-state and transient coupling conditions, which is in good agreement with the reference results; 2) Compared with the nodal-wise coupling calculation, the pin-by-pin wise coupling calculation improves the fuel peak temperature, the range of power distribution is expanded, and the lower limit is reduced more.

• 디지털산업정보학회논문지
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• 제12권1호
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• pp.51-61
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• 2016

Because the Apple Pay which created by U.S's Apple Inc. and launch of Samsung pay in last August in domestic, people have high interest in Pin-Tech industries and new method of easy payment. In this paper, it will study newly introduced Pin-Tech industries and marketability of Pin-Tech industries. Also it will propose safe use of Pin-Tech services based on cases in domestic and overseas. This paper is organized as follows. In Chapter 2, it will study concept of Pin-Tech services and status of Pin-Tech services in domestic and overseas. In Chapter 3, it will look technical trends of Pin-Tech services. In Chapter 4, it will propose direction based on analysis of cases of Pin-Tech services. This paper will finish with conclusion in Chapter 5. Given the global trends, Korea is now just took the first steps in new Pin-Tech era. The Pin-Tech services are in situations that it is not yet activated in domestic due to the various financial regulations and procedures. In this paper, it will shows cases of concerns of Pin-Tech services and domestic authentication which relates to easy payment certification. If Pin-Tech services are develop with easy payment certification and adapt to domestic environment and develop based on stability and security as mentioned in this paper, domestic Pin-Tech services and security technology will grow to the world level. Also it requires unceasing research and efforts from relevant government officials, security companies and Pin-Tech ICT companies.

• 한국IT서비스학회지
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• 제16권2호
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• pp.97-110
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• 2017

Due to development of IT, various Internet services via the non-face-to-face are increasing rapidly. In the past, the resident registration numbers (RRN) was used a mean of personal identification, but the use of RRN is prohibited by the relevant laws, and the personal identification services using alternative means are activated. According to the prohibition policy of RRN, i-PIN service appeared as an alternative means to identify a person. However, the user's knowledge-based i-PIN service continues to cause fraudulent issuance, account hijacking, and fraud attempts due to hacking accidents. Due to these problems, the usage rate of i-PIN service which performs a nationwide free personal identification service, is rapidly decreasing. Therefore, this paper proposes a technical safety enhancement method for security enhancement in the i-PIN-based personal identification service. In order to strengthen the security of i-PIN, this paper analyzes the encryption key exposure, key exchange and i-PIN authentication model problems of i-PIN and suggests countermeasures. Through the proposed paper, the i-PIN can be expected to be used more effectively as a substitution of RRN by suggesting measures to enhance the safety of personal identification information. Secured personal identification services will enable safer online non-face-to-face transactions. By securing the technical, institutional, and administrative safety of the i-PIN service, the usage rate will gradually increase.

• 실천공학교육논문지
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• 제16권3_spc호
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• pp.327-332
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• 2024

스마트 폰의 보급이 사용자에게 다양한 서비스를 제공하여 삶의 편리함을 주고 있다. 특히, 스마트 폰으로 사용자 인증 후에 손쉽게 온라인 금융거래가 이루어지고 있다. 사용자는 PIN을 이용한 인증으로 쉽게 서비스에 접근하지만 그로 인해 훔쳐보기나 레코딩과 같은 사회공학적 공격에 취약하다. 도어락에서 비밀번호 입력 시 허수를 포함하여 인증하는 방법을 스마트 폰에도 적용함으로써 사회공학적 공격에 대한 보안성을 높이고자 한다. 도어락은 PIN을 단말기 내에서 인증을 수행하지만 스마트 폰에서는 PIN 인증이 서버에서 처리하기 때문에 PIN 정보를 안전하게 전달해야 하는 문제가 있다. 제안기법을 통해 허수가 포함된 PIN을 여러 개 생성하여 해시값과 같은 가공값으로 전송하기 때문에 전송의 안정성을 보장하면서, 노출없이 PIN을 입력할 수 있는 기법으로 안전한 사용자 인증이 가능하다.

• 융복합기술연구소 논문집
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• 제5권1호
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• pp.27-31
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• 2015

A Pin-fin array is widely used to enhance the heat transfer in the internal cooling passage. The heat transfer distribution around the pin-fin is varied by the horseshoe vortex and flow separation. The difference of heat transfer coefficient induces the large thermal stress, which is one of the major reasons to break of hot components. So, it is required to enhance the heat transfer on the back side of pin-fin to solve the thermal stress problem. This study suggests the pin-fin with inclined jet hole and complex pin-fin/dimple array to enhance the heat transfer on the back side of pin-fin. The heat transfer coefficient is predicted by the numerical analysis, which is performed by CFX 14.0. The numerical results are obtained at Reynolds number, 10,000. The results show that the heat transfer on the back side of pin-fin is increased in both cases. Beside, the wake, which comes from dimple and jet, helps to develop the horseshoe vortex and increase the heat transfer on the next row pin-fin.

• Journal of Information Technology Applications and Management
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• 제22권4호
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• pp.159-179
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• 2015

In 2005, Korean government created the Internet Personal Identification Number (i-PIN) for a new online personal identification system to protect citizens' personal information against criminal abuse. However, i-PINs have not been widely in use over a decade. Although many people joined the i-PIN service, its actual use rate has been low. This study intends to identify the factors necessary to boost the continuous use of i-PINs. It was shown that government support and perceived security had a positive effect on the perceived ease of use and perceived usefulness of the i-PIN, respectively. Perceived security also directly affected the continuous use intention of the i-PIN. The perceived ease of use significantly affected the perceived usefulness, but it did not affect the intention to continuously use the i-PIN. The factor that had the most significant influence on the continuous use intention of the i-PIN was perceived usefulness. To increase the i-PIN use rate, Korean government must reduce users' anxiety through strict security functions, and must attempt to help people use the i-PIN easily.

• 한국전자파학회논문지
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• 제16권2호
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• pp.167-173
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• 2005

직렬 PIN 다이오드 스위치의 격리도는 PIN 다이오드의 병렬 커패시턴스에 의해 제한을 받으며, 스위치 구동회로는 PIN 다이오드 스위치의 스위칭 속도를 제한한다. 이런 문제를 극복하기 위해, 병렬 공진 인턱턴스와 TTL 호환의 스위치 구동회로가 적용된 높은 격리도와 고속 스위칭의 PIN 다이오드 스위치를 제안하였다. 3 GHz PIN 다이오드 스위치의 측정 결과, 1 GHz의 주파수 대역폭, 1.5 dB 이내의 삽입 손실, 65 dB의 격리도, 15 dB 이상의 반사 손실 그리고 30 ns 이내의 스위칭 속도를 나타내었다. 특히, 병렬 공진 인덕턴스를 사용한 3 GHz스위치는 15 dB의 격리도 향상을 나타내었다.

• Nuclear Engineering and Technology
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• 제52권11호
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• pp.2431-2441
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• 2020

Currently, the pin-by-pin homogenized solvers are a very active research field as they can, unlike the nodal codes, directly predict the local power, while requiring significantly less computational resources than the heterogeneous transport codes. This paper presents a recently developed pin-by-pin diffusion/SP3 solver Tortin, its spatial discretization method and the reflector treatment. Regarding the spatial discretization, it was observed that the finite difference method applied on pin-cell size mesh does not properly capture the big flux change between MOX and uranium fuel, while the nodal expansion method is more accurate but too slow. If the finite difference method is used with a finer mesh in the outer two pin rows of the fuel assembly, it increases the required computation time by only 50%, but decreases the pin power errors below 1% with respect to lattice code reference solutions. The paper further describes the coupling of Tortin with a microscopic depletion solver. Several verification tests show that the SP3 pin-by-pin solver can reproduce the heterogeneous transport solvers results with very good accuracy, even for fuel cycle depletion of very heterogeneous core employing MOX fuel or inserted control rods, while being two orders of magnitude faster.

• Molecules and Cells
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• 제38권9호
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• pp.814-820
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• 2015

PinX1, a nucleolar protein of 328 amino acids, inhibits telomerase activity, which leads to the shortening of telomeres. The C-terminal region of PinX1 is responsible for its nucleolar localization and binding with TERT, a catalytic component of telomerase. A fraction of TERT localizes to the nucleolus, but the role of TERT in the nucleolus is largely unknown. Here, we report a functional connection between PinX1 and TERT regarding PinX1 stability. The C-terminal of $PinX1^{205-328}$, a nucleolar fragment, was much more stable than the N-terminal of $PinX1^{1-204}$, a nuclear fragment. Interestingly, PinX1 was less stable in TERT-depleted cells and more stable in TERT-myc expressing cells. Stability assays for PinX1 truncation forms showed that both $PinX1^{1-328}$ and $PinX1^{205-328}$, nucleolar forms, were more rapidly degraded in TERT-depleted cells, while they were more stably maintained in TERT-overexpressing cells, compared to each of the controls. However, $PinX1^{1-204}$ was degraded regardless of the TERT status. These results reveal that the stability of PinX1 is maintained in nucleolus in the presence of TERT and suggest a role of TERT in the regulation of PinX1 steady-state levels.

• 한국전자파학회논문지
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• 제13권5호
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• pp.484-491
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• 2002

본 연구에서는 Ku-대역 위성통신 중계기에 사용되는 전압제어형 PIN 다이오드 감쇄기를 설계, 제작, 측정하고 이 감쇄기의 온도 특성 변화를 보상하기 위한 온도보상회로를 제안하였다. PIN 다이오드 감쇄기는 박막 하이브리드 기술을 이용하여 설계되었으며 PIN 다이오드 감쇄기를 전압제어형으로 사용할 경우 최대 선형 특성을 얻을 수 있는 부하 저항(R$_{L}$)의 값을 Simulation 및 실험에 의해 결정되었다. 최적의 부하 저항값은 사용한 PIN 다이오드의 특성에 의해 달라지며, 본 논문에서 사용한 APD-0805의 경우 150$\Omega$의 부하저항으로 PIN 다이오드 한 개에 10 dB 까지 선형 감쇄범위를 얻을 수 있었다. 또한 부하 저항을 포함한 PM 다이오드 감쇄기의 온도 특성을 측정하였고, 측정결과 관찰된 PIN 다이오드 감쇄기가 전압제어형으로 사용되어질 경우의 가장 큰 단점인 온도 특성의 심각한 변화를 보상할 수 있는 온도보상회로를 제안하였다. 제안된 온도보상회로를 갖는 PIN 다이오드 감쇄기는 동작온도에 대해 선형적인 특성을 보이며 동작온도 범위에 걸쳐 0.6 dB 이하의 오차만을 가짐을 확인하였다.