• 한국항해항만학회지
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• 제42권5호
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• pp.323-330
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• 2018

The Korean e-Navigation system is a Korean approach to correspond with implementation of IMO e-Navigation. It provides five services, among them SV20 service, a ship remote monitoring system that collects and processes sensor information related to fire, navigation, and seakeeping performance safety. The system also detects abnormal conditions such as fires, capsizing, sinking, navigation equipment failure during navigation, and calculates the safety index and determines the emergency level. According to emergency level, it provides appropriate emergency response guidance for the onboard operator. The fire safety module is composed of three sub-modules; each module is the safety index sub-module, the emergency level determination sub-module and emergency response guidance sub-module. In this study, operational concept of the fire safety module in SV20 service is explained, and fire safety assessment factors are estimated, to calculate the fire safety index. Fire assessment factors included 'Fire detector position factor,' 'Smoke diffusion rate factor,' and 'Fire-fighting facilities factor.'

• Korean Journal of Mathematics
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• 제29권2호
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• pp.267-269
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• 2021

A finitely generated torsion module M for ℤ_p[[T, T₂, ⋯ , T_d]] is pseudo-null if M/TM is pseudo-null over ℤ_p[[T₂, ⋯ , T_d]]. This result is used as a tool to prove the generalized Greenberg's conjecture in certain cases. The converse may not be true. In this paper, we give examples of pseudo-null Iwasawa modules whose reduction are not pseudo-null.

• Current Photovoltaic Research
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• 제8권3호
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• pp.102-106
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• 2020

In this paper, the effect of MoSe₂ on the contact resistance (R_C) of the transparent conducting oxide (TCO) and Mo junction in the scribed P2 region of the Cu(In,Ga)Se₂ (CIGS) solar module was analyzed. The CIGS/Mo junction becomes ohmic-contact by MoSe₂, so the formation of the MoSe₂ layer is essential. However, the CIGS solar module has a TCO/MoSe₂/Mo junction in the P2 region due to structural differences from the cell. The contact resistance (R_C) of the P2 region was calculated using the transmission line method, and MoSe₂ was confirmed to increase R_C of the TCO/Mo junction. B doped ZnO (BZO) was used as TCO, and when BZO/MoSe₂ junction was formed, conduction band offset (CBO) of 0.6 eV was generated due to the difference in their electron affinities. It is expected that this CBO acts as a carrier transport barrier that disturbs the flow of current, resulting in increased R_C. In order to reduce the R_C caused by CBO, MoSe₂ must be made thin in a CIGS solar module.

• 대한수학회보
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• 제59권1호
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• pp.141-154
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• 2022

Let R be a commutative ring with identity. Denote by w𝒫_w the class of weak w-projective R-modules and by w𝒫_w^⊥ the right orthogonal complement of w𝒫_w. It is shown that (w𝒫_w, w𝒫_w^⊥) is a hereditary and complete cotorsion theory, and so every R-module has a special weak w-projective precover. We also give some necessary and sufficient conditions for weak w-projective modules to be w-projective. Finally it is shown that when we discuss the existence of a weak w-projective cover of a module, it is enough to consider the w-envelope of the module.

• 전기전자학회논문지
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• 제23권4호
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• pp.1208-1217
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• 2019

풀-브리지 서브모듈은 MMC의 단위 시스템으로서 서브모듈에 대한 수명예측은 HVDC 시스템의 유지 보수와 경제성 확보 관점에서 매우 중요하다. 그러나 일반적으로 부품의 종류, 개수, 결합 상태만을 고려하는 수명 예측은 대상 시스템의 구동상태를 고려하지 않는 일반화 된 결과로 실제 시스템의 수명과 크게 차이가 발생할 수 있다. 따라서 본 논문에서는 풀-브리지 서브모듈의 동작 특성을 반영하기 위한 목적으로 고장나무를 설계하고 기본 사상의 고장률에 MIL-HDBK-217F를 적용하여 풀-브리지 서브모듈의 수명을 예측한다. 기존의 부품고장률 분석과 제안된 고장나무 분석에 의한 기대 수명을 비교하고, 풀-브리지 서브모듈의 여유율 적용 여부에 따른 수명을 비교한다.

• 대한수학회보
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• 제59권4호
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• pp.917-928
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• 2022

Let R be a commutative Noetherian ring and I an ideal of R. In this paper, we study colocalization of generalized local homology modules. We intend to establish a dual case of local-global principle for the finiteness of generalized local cohomology modules. Let M be a finitely generated R-module and N a representable R-module. We introduce the notions of the representation dimension r^I(M, N) and artinianness dimension a^I(M, N) of M, N with respect to I by r^I(M, N) = inf{i ∈ ℕ₀ : H^I_i(M, N) is not representable} and a^I(M, N) = inf{i ∈ ℕ₀ : H^I_i(M, N) is not artinian} and we show that a^I(M, N) = r^I(M, N) = inf{r^IR_𝔭 (M_𝔭,𝔭N) : 𝔭 ∈ Spec(R)} ≥ inf{a^IR_𝔭 (M_𝔭,𝔭N) : 𝔭 ∈ Spec(R)}. Also, in the case where R is semi-local and N a semi discrete linearly compact R-module such that N/∩_t>0I^tN is artinian we prove that inf{i : H^I_i(M, N) is not minimax}=inf{r^IR_𝔭 (M_𝔭,𝔭N) : 𝔭 ∈ Spec(R)＼Max(R)}.

• 전기학회논문지
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• 제66권2호
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• pp.357-362
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• 2017

Among the lithium metal oxides for asymmetric hybrid supercapacitor, $Li_4Ti_5O_{12}(LTO)$ is an emerging electrode material as zero-stain material in volume change during the with the charging and discharging processes. The pulverized LTO powder was observed to show the enhanced capacity from 120 mAh/g to 156 mAh/g at C-rate (10, 100 C). Hybrid supercapacitor module(48V, 416F) was fabricated using an asymmetric hybrid capacitor with a capacitance of 7500F. As a result of the measurement of C-rate characteristics, the module shows that the discharge time is drastically reduced at more than 50C, and the ESR and voltage drop characteristics are increased. The energy density and power density were reduced under high C-rate conditions. When designing asymmetric hybrid supercapacitor module, the C-rate and ESR should be considered As a result of measuring the 5 kw UPS, it was discharged at the current of 116A~170A during the discharge in the voltage range of 48V~30V, and the compensation time at discharge was measured to be about 33.2s. Experimental results show that it can be applied to applications related to stabilization of power quality by applying hybrid supercapacitor module.

• Nuclear Engineering and Technology
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• 제53권6호
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• pp.1893-1908
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• 2021

In light of the importance of helium production in influencing the behaviour of fast reactor fuels, in this work we present a burn-up module with the objective to calculate the production of helium in both in-pile and out-of-pile conditions tracking the evolution of 23 alpha-decaying actinides. This burn-up module relies on average microscopic cross-section look-up tables generated via SERPENT high-fidelity calculations and involves the solution of the system of Bateman equations for the selected set of actinide nuclides. The results of the burn-up module are verified in terms of evolution of actinide and helium concentrations by comparing them with the high-fidelity ones from SERPENT, considering two representative test cases of (U,Pu)O₂ fuel in fast reactor conditions. In addition, a code-to-code comparison is made with the independent state-of-the-art module TUBRNP (implemented in the TRANSURANUS fuel performance code) for the same test cases. The herein presented burn-up module is available in the SCIANTIX code, designed for coupling with fuel performance codes.

• 마이크로전자및패키징학회지
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• 제26권4호
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• pp.119-126
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• 2019

18쌍의 Bi₂Te₃계 p-n 가압소결체 열전레그들로 구성되어 있으며 상하부 기판이 없고 내부는 polydimethylsiloxane (PDMS)로 충진되어 있는 유연열전모듈을 형성하고, 이의 발전특성과 굽힘특성을 분석하였다. 유연열전모듈을 팔목에 부착하였을 때 서있는 정적인 상태에서는 2.23 mV의 open circuit 전압과 1.69 ㎼의 최대출력전력이 얻어졌으며, 걸어가는 동적인 상태에서는 3.32 mV의 open circuit 전압과 3.41 ㎼의 최대출력전력이 얻어졌다. 유연열전모듈에 굽힘곡률반경 25 mm로 30,000회까지 반복굽힘 싸이클을 인가하여도 저항변화율이 1% 미만으로 유지되었다.

• 대한수학회보
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• 제58권3호
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• pp.689-698
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• 2021

In this paper, we show some results on the artinianness of local cohomology modules with respect to a system of ideals. If M is a 𝚽-minimax ZD-module, then H^{dim M}_𝚽(M)/𝖆H^{dim M}_𝚽(M) is artinian for all 𝖆 ∈ 𝚽. Moreover, if M is a 𝚽-minimax ZD-module, t is a non-negative integer and Hⁱ_𝚽(M) is minimax for all i > t, then Hⁱ_𝚽(M) is artinian for all i > t.