Impact of Diltiazem Alone versus Diltiazem with Nitrate on Five-Year Clinical Outcomes in Patients with Significant Coronary Artery Spasm

Park, Taeshik,Park, Ji Young,Rha, Seung-Woon,Seo, Hong Seog,Choi, Byoung Geol,Choi, Se Yeon,Byun, Jae Kyeong,Park, Sang-Ho,Park, Eun Jin,Choi, Jah Yeon,Park, Sung Hun,Lee, Jae Joong,Lee, Sunki,Na, Jin Yonsei University, College of Medicine 2017 Yonsei medical journal Vol.58 No.1

<P><B>Purpose</B></P><P>Calcium channel blockers diltiazem and nitrate have been used as selective coronary vasodilators for patients with significant coronary artery spasm (CAS). However, no study has compared the efficacy of diltiazem alone versus diltiazem with nitrate for long-term clinical outcomes in patients with CAS.</P><P><B>Materials and Methods</B></P><P>A total of 2741 consecutive patients without significant coronary artery disease with positive CAS by acetylcholine (Ach) provocation test between November 2004 and May 2014 were enrolled. Significant CAS was defined as a narrowing of >70% by incremental intracoronary injection of 20, 50, and 100 µg of Ach into the left coronary artery. Patients were assigned to either the diltiazem group (n=842) or the dual group (diltiazem with nitrate, n=1899) at physician discretion. To adjust for potential confounders, a propensity score matching (PSM) analysis was performed using the logistic regression model. After PSM analysis, two well-balanced groups (811 pairs, n=1622, C-statistic=0.708) were generated.</P><P><B>Results</B></P><P>At 5 years, there were similar incidences in primary endpoints, including mortality, myocardial infarction, revascularization, and recurrent angina requiring repeat coronary angiography between the two groups. Diltiazem alone was not an independent predictor for major adverse cardiovascular events or recurrent angina requiring repeat coronary angiography.</P><P><B>Conclusion</B></P><P>Despite the expected improvement of endothelial function and the relief of CAS, the combination of diltiazem and nitrate treatment was not superior to diltiazem alone in reducing mortality and cardiovascular events up to 5 years in patients with significant CAS.</P>

Multi-hop-based opportunistic concurrent directional transmission in 60 GHz WPANs

Park, Hyunhee,Park, Seunghyun,Shon, Taeshik,Kim, Eui-Jik Springer-Verlag 2015 MULTIMEDIA TOOLS AND APPLICATIONS Vol.74 No.5

Impact of Cigarette Smoking: a 3-Year Clinical Outcome of Vasospastic Angina Patients

Byoung Geol Choi,Seung-Woon Rha,Taeshik Park,Se Yeon Choi,Jae Kyeong Byun,Min Suk Shim,Shaopeng Xu,Hu Li,Sang-Ho Park,Ji Young Park,Woong Gil Choi,Yun-Hyeong Cho,이선기,Jin Oh Na,Cheol Ung Choi,Hong Euy 대한심장학회 2016 Korean Circulation Journal Vol.46 No.5

However, it is largely unknown whether smoking adds to any long-term clinical risk in VSA patients. Subjects and Methods: A total of 2797 patients without significant CAD underwent acetylcholine (Ach) provocation test between November 2004 and October 2010. Patients were divided into three groups, based on the presence of coronary artery spasm (CAS) and smoking habits (non-CAS group: n=1188, non-smoking CAS group: n=1214, smoking CAS group: n=395). All CAS patients were prescribed with anti-anginal medications for at least 6 months. The incidence of major clinical outcomes and recurrent angina of these groups were compared up to 3 years. Results: There were considerable differences in the baseline clinical and angiographic characteristics among the three groups, but there was no difference in the endpoints among the three groups (including individual and composite hard endpoints) such as death, myocardial infarction, de novo percutaneous coronary intervention, cerebrovascular accident, and major adverse cardiac events. However, there was a higher incidence of recurrent angina in both the non-smoking CAS group and smoking CAS group, as compared to the nonCAS group. In multivariable adjusted Cox-proportional hazards regression analysis, smoking CAS group exhibited a higher incidence of recurrent angina compared with the non-CAS group (hazard ratio [HR]; 2.46, 95% confidence interval [CI]; 1.46-4.14, p=0.001) and nonsmoking CAS group (HR; 1.76, 95% CI; 1.08-2.87, p=0.021). Conclusion: Cigarette smoking CAS group exhibited higher incidence of recurrent angina during the 3-year clinical follow-up compared with both the non-CAS group and non-smoking CAS group. Quitting of smoking, paired with intensive medical therapy and close clinical follow-up, can help to prevent recurrent angina.

A Hybrid Adaptive Security Framework for IEEE 802.15.4-based Wireless Sensor Networks

( Taeshik Shon ),( Yongsuk Park ) 한국인터넷정보학회 2009 KSII Transactions on Internet and Information Syst Vol.3 No.6

With the advent of ubiquitous computing society, many advanced technologies have enabled wireless sensor networks which consist of small sensor nodes. However, the sensor nodes have limited computing resources such as small size memory, low battery life, short transmission range, and low computational capabilities. Thus, decreasing energy consumption is one of the most significant issues in wireless sensor networks. In addition, numerous applications for wireless sensor networks are recently spreading to various fields (health-care, surveillance, location tracking, unmanned monitoring, nuclear reactor control, crop harvesting control, u-city, building automation etc.). For many of them, supporting security functionalities is an indispensable feature. Especially in case wireless sensor networks should provide a sufficient variety of security functions, sensor nodes are required to have more powerful performance and more energy demanding features. In other words, simultaneously providing security features and saving energy faces a trade-off problem. This paper presents a novel energy-efficient security architecture in an IEEE 802.15.4-based wireless sensor network called the Hybrid Adaptive Security (HAS) framework in order to resolve the trade off issue between security and energy. Moreover, we present a performance analysis based on the experimental results and a real implementation model in order to verify the proposed approach.

A Secure and Robust Connectivity Architecture for Smart Devices and Applications

Shon, Taeshik,Han, Kyusuk,Park, James J. (Jong hyuk),Jeong, Young-Sik,Lee, Yang Sun Hindawi Publishing Corporation 2011 EURASIP journal on wireless communications and net Vol.2011 No.-

<P>Convergence environments and technologies are urgently coming close to our life with various wireless communications and smart devices in order to provide many benefits such as connectivity, usability, mobility, portability, and flexibility as well as lower installation and maintenance costs. Convergence has brought important change not only in the way we live but also in the way we think. It is the progress towards the attempt to create and to evolve new valuable services through the device convergence and fusion of in-home, office, and various environments around the personal mobile apparatus. Based on the dynamic trends of convergence, it is widely argued that the increased requirements on secure and robust connectivity between a variety of mobile devices and their applications provide us the era of real pervasive computing environment. Thus, in this paper, we present a novel connectivity architecture using RF4CE-(Radio Frequency for Consumer Electronics-) based wireless zero-configuration and enhanced key agreement approach. We analyze the security and performance of our proposed approach by the development of the prototype H/W and the construction of a testbed with CE and mobile devices.</P>

[1]Benzothieno[3,2-b][1]benzothiophene-based liquid crystalline organic semiconductor for solution-processed organic thin film transistors

Woobyung Park,Chaeyoung Yun,Seungjae Yun,이재진,배상욱,호동일,Taeshik Earmme,김충익,SungYong Seo 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.114 No.-

Liquid crystalline organic semiconductors have drawn tremendous interest due to potentials of applicationsin organic thin-film transistors (OTFTs) with their high electrical performance and solutionprocessability. However, alkylated liquid crystals often encounter poor thermal durability and mobilitydrop at smectic E (SmE) phase. Here, we introduce new solution-processable [1]benzothieno[3,2-b][1]benzothiophene-based small molecules with different types of alkyl side chains for OTFTs. All BTBT derivativesshowed smectic phase; dialkylated 2-octyl-7-(50-octyl-[2,20-bithiophen]-5-yl)benzo[b]benzo[4,5]thieno[2,3-d]thiophene (O-2Th-BTBT) and 2-(50-(2-ethylhexyl)-[2,20-bithiophen]-5-yl)-7-octylbenzo[b]benzo[4,5]thieno[2,3-d]thiophene (E-2Th-BTBT) suffered mobility degradation at SmE phase. However,monoalkylated 2-([2,20-bithiophen]-5-yl)-7-octylbenzo[b]benzo[4,5]thieno[2,3-d]thiophene (2Th-BTBT)did not exhibit SmE phase over temperature range, resulting in high carrier mobility up to 0.31 cm2/Vsthrough molecular bilayer transition by thermal annealing. Physicochemical and liquid crystal propertieswere analyzed, and thin film characterization by atomic force microscopy and X-ray diffraction wasdiscussed.

Novel Approaches to Enhance Mobile WiMAX Security

Shon, Taeshik,Koo, Bonhyun,Park, Jong Hyuk,Chang, Hangbae Hindawi Publishing Corporation 2010 Eurasip Journal on Wireless Communications and Net Vol.2010 No.-

<P>The IEEE 802.16 Working Group on Broadband Wireless Access Standards released IEEE 802.16-2004 which is a standardized technology for supporting broadband and wireless communication with fixed and nomadic access. After the IEEE 802.16-2004 standard, a new advanced and revised standard was released as the IEEE 802.16e-2005 amendment which is foundation of Mobile WiMAX network supporting handover and roaming capabilities. In the area of security aspects, compared to IEEE 802.16-2004, IEEE 802.16e, called Mobile WiMAX, adopts improved security architecture—PKMv2 which includes EAP authentication, AES-based authenticated encryption, and CMAC or HMAC message protection. However, there is no guarantee that PKMv2-based Mobile WiMAX network will not have security flaws. In this paper, we investigate the current Mobile WiMAX security architecture focusing mainly on pointing out new security vulnerabilities such as a disclosure of security context in network entry, a lack of secure communication in network domain, and a necessity of efficient handover supporting mutual authentication. Based on the investigation results, we propose a novel Mobile WiMAX security architecture, called RObust and Secure MobilE WiMAX (ROSMEX), to prevent the new security vulnerabilities.</P>

인터넷 트래픽의 정보은닉 기법 분석

손태식(TaeShik Shon),박종성(JongSeong Park),문종섭(JongSub Moon) 한국정보보호학회 2004 情報保護學會誌 Vol.14 No.2

은닉채널에 관한 연구는 1980년대 이전부터 진행되어 왔으며, 최근에는 멀티미디어 데이터에 대한 스테가노그래피에 대한 관심이 집중되고 있다. 하지만, 본 논문에서는 현재 스테가노그래피나 정보은닉에서 다루는 동영상 데이터에 대한 은닉채널이 아닌, 인터넷 환경의 근간을 이루는 TCP/IP 네트워크 트래픽에 존재하는 은닉채널에 대한 연구를 수행하였다. 먼저 은닉채널 개념 및 기존 연구동향을 분석하였으며, 그 후 TCP/IP를 구성하는 각 프로토콜에 생성 가능한 은닉채널을 분석하여 향후 연구 방향을 제시하였다.

Healing Graphene Defects Using Selective Electrochemical Deposition: Toward Flexible and Stretchable Devices

Yoon, Taeshik,Kim, Jae-Han,Choi, Jun Hyung,Jung, Dae Yool,Park, Ick-Joon,Choi, Sung-Yool,Cho, Nam Sung,Lee, Jeong-Ik,Kwon, Young-Duck,Cho, Seungmin,Kim, Taek-Soo American Chemical Society 2016 ACS NANO Vol.10 No.1

<P>Graphene produced by chemical-vapor-deposition inevitably has defects such as grain boundaries, pinholes, wrinkles, and cracks, which are the most significant obstacles for the realization of superior properties of pristine graphene. Despite efforts to reduce these defects during synthesis, significant damages are further induced during integration and operation of flexible and stretchable applications. Therefore, defect healing is required in order to recover the ideal properties of graphene. Here, the electrical and mechanical properties of graphene are healed on the basis of selective electrochemical deposition on graphene defects. By exploiting the high current density on the defects during the electrodeposition, metal ions such as silver and gold can be selectively reduced. The process is universally applicable to conductive and insulating substrates because graphene can serve as a conducting channel of electrons. The physically filled metal on the defects improves the electrical conductivity and mechanical stretchability by means of reducing contact resistance and crack density. The healing of graphene defects is enabled by the solution-based room temperature electrodeposition process, which 'broadens the use of graphene as an engineering material.</P>

자동화된 침해사고대응시스템에서의 네트웍 포렌식 정보에 대한 정의

박종성(JongSeong Park),최운호(UnHo Choi),문종섭(Jongsub Moon),손태식(Taeshik Shon) 한국정보보호학회 2004 정보보호학회논문지 Vol.14 No.4

포렌식에 관한 연구는 현재까지 피해 컴퓨터에 남은 흔적을 수집하고 가공, 보관하는 시스템 포렌식에 치우쳐 있었다. 최근들어 단순히 피해 컴퓨터에 남은 흔적만을 분석하는 것이 아닌 컴퓨터 시스템이 속한 전체 네트웍에서 침입 관련 정보를 얻고 분석하려는 네트웍 포렌식에 대한 연구가 활발하다. 특히나 자동화된 침해사고대응시스템에서는 전체 네트웍에 대한 침입 흔적을 다루어야 하기 때문에 네트웍 포렌식의 중요성이 크다고 할 수 있다. 본 논문에서는 자동화된 침해사고대응시스템에서 네트웍 포렌식 정보로서 수집되어야 할 정보들을 정의하고 정의된 정보들을 가상의 침해사고 시나리오를 통해 확인한다. Until now the study of computer forensics has been focused only system forensics which carried on keeping, processing and collecting the remained evidence on computer. Recently the trend of forensic study is proceeding about the network forensics which analyze the collected information in entire networks instead of analyzing the evidence on a victim computer. In particular network forensics is more important in Automated Computer Emergency Response System because the system deals with the intrusion evidence of entire networks. In this paper we defined the information of network forensics that have to be collected in Automated Computer Emergency Response System and verified the defined information by comparing with the collected information in experimental environments.