Refraction traveltime tomography using damped monochromatic wavefield

Sukjoon Pyun,Changsoo Shin 한국암반공학회 2003 한국암반공학회 학술대회 및 세미나 자료집 Vol.- No.-

South Korea’s Middle-Power Diplomacy and the Future of India-South Korea Strategic Cooperation

( Sukjoon Yoon ) 경남대학교 극동문제연구소 2014 국제관계연구 시리즈 Vol.32 No.0

CSSP2: An improved method for predicting contact-dependent secondary structure propensity

Sukjoon Yoon,William J. Welsh,Heeyoung Jung,Young Do Yoo Sookmyung Women's University Research Institute of 2007 여성과 건강 Vol.3 No.1

From Confrontation to Conflict between China and Taiwan: Major Challenges for Taiwan’s Counter Strategy

( Sukjoon Yoon ),( Junho Yun ) 한국국방연구원 2020 The Korean Journal of Defense Analysis Vol.32 No.3

This article explores the issue of Taiwan’s security, increasingly threatened by China’s overwhelming military power. Taiwan has long been protected by a security commitment from the United States, but recent geopolitical shifts and technological developments have raised questions about the effectiveness of Taiwan’s strategy. Operational concepts and tactics, such as Taiwan’s A2/AD defense against the PLA are severely challenged by China’s enhanced amphibious capabilities. Taiwan now looks vulnerable to a full-scale amphibious assault by the PLA, and the U.S. commitment has been undermined by the transactional emphasis of the current administration, with Taiwan seen primarily as a tool to contain Chinese expansionism rather than an end in and of itself. Clearly, the Taiwanese military needs to up its game, and this article makes four recommendations: First, Taiwan should significantly increase its independent military capabilities, forcing Chinese military planners to reconsider whether the military options against Taiwan are worthwhile. Second, Taiwan should deploy its substantial technological prowess to strengthen its cyber warfare defenses. Third, Taiwan should rapidly acquire advanced foreign-made weapons and systems, abandoning its costly and timeconsuming indigenous development policies. Fourth, Taiwan’s leaders should give serious consideration to developing nuclear weapons, as only this can deter the Chinese military threat in the long term.

GEOLOGICALLY CONSTRAINED FULL WAVEFORM INVERSION

Sukjoon PYUN,Yunhui PARK 한국산업응용수학회 2013 한국산업응용수학회 학술대회 논문집 Vol.8 No.1

It is apparent that full waveform inversion with regularization shows a better result than with no regularization. However, it may fail to delineate sharp geological structures such as faults and salt boundaries. Hence, the geological information should be considered to recover accurate subsurface structures. In this paper, an adaptive smoothing regularization is implemented based on local slope. The adaptive regularization incorporates geological information into inversion process. Local slopes are calculated using the Hilbert transform and stabilized through isotropic and edge-enhancing smoothing before and after calculating local slopes, respectively. The adaptive smoothing regularization is applied to the full waveform inversion for a synthetic subsurface model. The inversion result shows that the layer interfaces are faithfully preserved and sharpened.

SIMULTANEOUS-SOURCE FULL WAVEFORM INVERSION AND ITS COMPUTATIONAL EFFICIENCY

Sukjoon PYUN 한국산업응용수학회 2013 한국산업응용수학회 학술대회 논문집 Vol.8 No.1

Diagnostic Criteria of T1-Weighted Imaging for Detecting Intraplaque Hemorrhage of Vertebrobasilar Artery Based on Simultaneous Non-Contrast Angiography and Intraplaque Hemorrhage Imaging

Sukjoon Lim,Nam Hyeok Kim,곽효성,Seung Bae Hwang,Gyung Ho Chung 대한자기공명의과학회 2021 Investigative Magnetic Resonance Imaging Vol.25 No.4

Purpose: To investigate the diagnostic criteria of T1-weighted imaging (T1W) and time-of-flight (TOF) imaging for detecting intraplaque hemorrhage (IPH) of a vertebrobasilar artery (VBA) compared with simultaneous non-contrast angiography and intraplaque hemorrhage (SNAP) imaging. Materials and Methods: Eighty-seven patients with VBA atherosclerosis who underwent high resolution MR imaging for evaluation of VBA plaque were reviewed. The presence and location of VBA plaque and IPH on SNAP were determined. The signal intensity (SI) of the VBA plaque on T1W and TOF imaging was manually measured and the SI ratio against adjacent muscles was calculated. The receiveroperating characteristic (ROC) curve was used to compare the diagnostic accuracy for detecting VBA IPH. Results: Of 87 patients, 67 had IPH and 20 had no IPH on SNAP. The SI ratio between VBA IPH and temporalis muscle on T1W was significantly higher than that in the noIPH group (235.9 ± 16.8 vs. 120.0 ± 5.1, P < 0.001). The SI ratio between IPH and temporalis muscle on TOF was also significantly higher than that in the no-IPH group (236.8 ± 13.3 vs. 112.8 ± 7.4, P < 0.001). Diagnostic efficacies of SI ratios on TOF and TIW were excellent (AUC: 0.976 on TOF and 0.964 on T1W; cutoff value: 136.7% for TOF imaging and 135.1% for T1W imaging). Conclusion: Compared with SNAP, cutoff levels of the SI ratio between VBA plaque and temporalis muscle on T1W and TOF imaging for detecting IPH were approximately 1.35 times.

Digital selective laser methods for nanomaterials: From synthesis to processing

Hong, Sukjoon,Lee, Habeom,Yeo, Junyeob,Ko, Seung Hwan Elsevier 2016 Nano Today Vol.11 No.5

<P><B>Abstract</B></P> <P>Laser has long been used for material processing, and its applications to nanomaterials for their direct synthesis, positioning and processing are currently active fields of study. The main mechanism of typical laser processes is photothermal reaction by a focused laser that remotely generates confined temperature field at a desired position with high controllability. The laser-induced elevated temperature enables direct synthesis of nanomaterials in both gas and liquid environment as well as photophysical processing of nanomaterials through melting or vaporization, represented by laser sintering and ablation processes, in spatially selective manners. On the other hand, recent advances in laser process further incorporates not only different optical responses such as optical forces and photochemical reactions for more advanced manipulation of nanomaterials, but also the interaction between electromagnetic waves, nanostructures and underlying substrates to facilitate novel processing those cannot be achieved by any other means including laser nanowelding for percolation network and laser thinning for two dimensional nanomaterials. At the same time, the shortcomings of laser process in nanomaterial processing such as limited resolution and low throughput are tackled through introducing different optical schemes together with the integration with other systems. In this review, we summarize the development and current status of digital selective laser methods for nanomaterials in broad aspects that cover from nanomaterial synthesis to its processing.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Digital selective laser processes for nanomaterials are summarized in this review. </LI> <LI> Nanomaterials are selectively synthesized, positioned, controlled and manipulated. </LI> <LI> These processes rely on photothermal, photochemical or photothermochemical reaction. </LI> <LI> More emphasis is placed on the processes for nanoparticles, nanowires and nanosheets. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

총수익스왑(TRS1))에 관한 연구 - 상법상 상호주식 규제여부에 대한 서울남부지법 2015. 6. 11. 2014가합4256 판결을 중심으로

이석준 ( Sukjoon Lee ) 한국상사판례학회 2016 상사판례연구 Vol.29 No.3

총수익스왑은 주식 등의 준거자산을 스왑 매도인이 자신의 이름으로 매입하도록 하면서 준거자산의 가치 등락에 따른 손익은 스왑 매수인에게 귀속시키는 장외파생상품이다. 따라서 총수익스왑에서는 주식에 부착된 의결권은 매도인이, 경제적 지분은 매수인이 각 취득하게 된다. 통상적으로 매도인은 금융기관이고 매수인은 투자자이므로, 매도인은 매수인으로부터 고정적인 이자로써 수수료를 지급받는데 관심이 있을 뿐의결권 행사에 관심이 없다. 결국 관행상 고객인 매수인의 의향에 따라 의결권을 행사하게 되므로 매수인은 이를 이용하여 주식의 의결권 수를 기반으로 한 각종 규제를 회피하려고 하는 현상이 나타나게 된다. 이에 대하여 매수인은 은닉의결권 또는 은닉소유권을 가지고 있다고 볼 수 있다. 대상판결은 총수익스왑에서 나타나는 은닉의결권과 관련한 사안으로, 다른 회사 발행주식총수의 10% 이상을 취득한 회사가 총수익스왑의 방식으로 일부를 처분함으로써 다른 회사가 보유하고 있는 회사의 주식이여전히 상법 제269조 제3항에 따라 의결권이 제한되는 상호주식에 해당하는지 문제되었다. 이에 대하여 서울남부지방법원은 2015. 6. 11. 회사가 총수익스왑의 방식으로 제3자에게 처분한 주식은 회사가 자기의 계산으로 주식을 취득한 경우에 해당한다고 볼 수 없다고 하여 위 규정의 적용을 받지 않는다고 판시하면서, 그 기준으로 ① 의결권 또는 우선매수청구권의 귀속, ②주식에 대한 매도인의 임의 처분가능성, ③ 주식매매대금의 부담자 및 손익의 귀속 등을 들었다. 그러나 위 기준들은 총수익스왑과 같은 의결권이 은닉된 사안에서는 합리적 기준으로 볼 수 없거나 그 기준을 사안에 대하여 구체적으로 적용하는 과정에 있어 타당하다고 보기는 어렵다고 생각한다. 따라서 이러한 한계를 고려하여 상법 제369조 제3항과 관련하여 총수익스왑의 경우에 이를 규제할 것인지, 규제한다면 그 규제방안으로 어떠한 것들이 있는지 생각해 볼 수 있을 것이다. 이 글에서는 의결권을 제한하는 방식으로 규제를 하되, 그 구체적인 규제방안으로 해석론과 입법론으로 나누어살펴보았다. Total return swap(TRS) is an OTC derivative in which one party(Total return payer) purchaces an underlying asset like a share while the other party(Total return receiver) acquires the return of an underlying asset, which includes both the income it generates and any capital gains. In TRS, therefore a payer acquires a voting right from a share and a receiver gains an economic ownership. Usually while a payer is a financial institution a receiver is a investor, so a payer tends to be only interested in commissions paid by a receiver, not his voting right. In eventually a payer usually exercises the vote following his client(a receiver)``s intention, and using this, a receiver wants to evade various legal regulations based on the number of voting rights. In this behalf, we call a receiver acquiring a “hidden ownership”. This case concerning a hidden ownership shown in TRS, deals with whether one company``s shares which other company holds are "Mutual owned stocks" limited voting rights under Article §369. 3. of the Korean commercial law, when a company who acquires over 10% of other company``s total number of issued stocks, sells a part of that stocks by means of TRS to deplete below 10% of total number of issued stocks. In this case, June 11th 2015, judges of Seoul southern district court decided in favor of the defendant by reason that the shares are not "Mutual owned stocks“ acquired on "it``s own account" and applied standards as follows. ① Whether a receiver gains a right to order a payer to exercise the votes or a right to claim for the shares preferentially, ② Whether a payer can sell the shares at any time at his discretion without a receiver``s intention. ③ Whether a receiver raised funds to purchase the shares and whether a receiver gains all of profits and losses from the shares. However theses standards are hardly rational or appropriate in the process of applying them concretely in this TRS case. Therefore we have to consider whether regulating TRS in reference to applying Article §369 (3) and how regulate it. In this study, I think we have to regulate TRS in the case of "Mutual owned stocks" by means of limiting voting rights and consider various solution plans like a theory of interpretation or a theory of legislation.

CSSP2 : An improved method for predicting contact-dependent secondary structure propensity

Yoon, Sukjoon,Welsh, Willian J,Jung, Heeyoung,Yoo, Young Do Research Institute of Women's Health Sookmyung Wom 2007 WOMEN And HEALTH Vol.3 No.1

The calculation of contact-dependent secondary structure propensity (CSSP) has been reported to sensitively detect non-native β-strand propensities in the core sequences of amyloidogenic proteins. Here we describe a noble energy-based CSSP method implemented on dual artificial neural networks that rapidly and accurately estimate the potential for the non-native secondary structure formation in local regions of protein sequences. In this method, we attempted to quantify long-range interaction patterns in diverse secondary structures by potential energy calculations and decomposition on a pairwise per-residue basis. The calculated energy parameters and seven-residue sequence information were used as inputs for artificial neural networks (ANNs) to predict sequence potential for secondary structure conversion. The trained single ANN using the >(i, i ± 4) interaction energy Parameter exhibited 74% accuracy in predicting the secondary structure of test sequences in their native energy state, while the dual ANN-based predictor using (i, i ± 4) and >(i, i ± 4) interaction energies showed 83% prediction accuracy. The present method provides a simple and accurate tool for predicting sequence potential for secondary structure conversions without using 3D structural information.