An Optimal Design Procedure based on the Safety Integrity Level for Safety-related Systems

( Sung Kyu Kim ),( Yong Soo Kim ) 한국인터넷정보학회 2018 KSII Transactions on Internet and Information Syst Vol.12 No.12

Safety-related systems (SRSs) has widely used in shipbuilding and power generation to prevent fatal accidents and to protect life and property. Thus, SRS performance is a high priority. The safety integrity level (SIL) is the relative performance level of an SRS with regard to its ability to operate reliably in a safe manner. In this article, we proposed an optimal design procedure to achieve the targeted SIL of SRSs. In addition, a more efficient failure mode and effects diagnostic analysis (FMEDA) process and optimization model were developed to improve cost efficiency. Based on previous IEC 61508 diagnostic analyses that revealed unnecessary costs associated with excessive reliability, the new approach consists of two phases: (i) SIL evaluation by FMEDA, and (ii) solution optimization for achieving the target SIL with minimal cost using integer-programming models. The proposed procedure meets the required safety level and minimizes system costs. A case study involving a gas-detection SRS was conducted to demonstrate the effectiveness of the new procedure.

[Colorectal] Recurrent Rectal Prolapse Surgical Management: A Single Center Retrospective Study

Sung Kyu Kim,Jae Kyun Ju,Jun Seong Chung,Han Deok Kwak 대한외과학회 2022 대한외과학회 학술대회 초록집 Vol.2022 No.11

Si 도핑이 InAs 자기조립 양자점 적외선 소자 특성에 미치는 효과

서동범,황제환,오보람,김준오,이상준,김의태,Seo, Dong-Bum,Hwang, Je-hwan,Oh, Boram,Kim, Jun Oh,Lee, Sang Jun,Kim, Eui-Tae 한국재료학회 2019 한국재료학회지 Vol.29 No.9

We investigate the characteristics of self-assembled quantum dot infrared photodetectors(QDIPs) based on doping level. Two kinds of QDIP samples are prepared using molecular beam epitaxy : $n^+-i(QD)-n^+$ QDIP with undoped quantum dot(QD) active region and $n^+-n^-(QD)-n^+$ QDIP containing Si direct doped QDs. InAs QDIPs were grown on semi-insulating GaAs (100) wafers by molecular-beam epitaxy. Both top and bottom contact GaAs layer are Si doped at $2{\times}10^{18}/cm^3$. The QD layers are grown by two-monolayer of InAs deposition and capped by InGaAs layer. For the $n^+-n^-(QD)-n^+$ structure, Si dopant is directly doped in InAs QD at $2{\times}10^{17}/cm^3$. Undoped and doped QDIPs show a photoresponse peak at about $8.3{\mu}m$, ranging from $6{\sim}10{\mu}m$ at 10 K. The intensity of the doped QDIP photoresponse is higher than that of the undoped QDIP on same temperature. Undoped QDIP yields a photoresponse of up to 50 K, whereas doped QDIP has a response of up to 30 K only. This result suggests that the doping level of QDs should be appropriately determined by compromising between photoresponsivity and operating temperature.

Development and Performance Analysis of a 22.9 kV/50 MVA Tri-axial HTS Power Cable Core

Sung-Kyu Kim,Sun-Kyoung Ha,Jin-Geun Kim,Bo-Geun Jang,Minwon Park,In-Keun Yu,Sangjin Lee,Kideok Sim,A-Rong Kim IEEE 2013 IEEE transactions on applied superconductivity Vol.23 No.3

<P>Tri-axial high-temperature superconducting (HTS) power cables are being developed to maximize their advantages such as reduced amount of HTS wires, a low-leakage magnetic field, and compactness compared with the different types of HTS power cables. The authors designed a 22.9 kV/50 MVA-class tri-axial HTS power cable core to apply to the distribution system in Korea. The inherent imbalance in the three-phase currents of the tri-axial HTS power cable core was calculated using the impedance matching program. A tri-axial HTS power cable core was fabricated using second-generation YBCO wires and the cable core was tested under 77 K liquid nitrogen to verify the performance of the cable core through obtaining its electrical characteristics data. This paper describes the results of the design, fabrication, and evaluation of the 22.9 kV/50 MVA-class tri-axial HTS power cable core. They will be used to develop a tri-axial HTS power cable for the distribution system.</P>

Anti-oxidative and Inhibitory Activities on Nitric Oxide (NO) and Prostaglandin E2 (COX-2) Production of Flavonoids from Seeds of Prunus tomentosa Thunberg

Sung Kyu Kim,Hyun Jung Kim,Sun Eun Choi,박관희,최형균,이민원 대한약학회 2008 Archives of Pharmacal Research Vol.31 No.4

Chemical investigation of the 80% Me2CO extract from the seeds of Prunus tomentosa led to the isolation and identification of six flavonoids: kaempferol (1), kaempferol 3-O-α-L-rhamnopyranoside (2; afzelin), kaempferol 3-O-β-D-(6-acetyl)-glucopyranosyl(1→4)-α-L-rhamnopyranoside (3; multiflorin A), kaempferol 3-O-β-D-glucopyranosyl(1→4)-α-L-rhamnopyranoside (4; multiflorin B), quercetin 3-O-α-L-rhamnopyranoside (5; quercitrin), and quercetin 3-O-β-D-glucopyranosyl (1→4)-α-L-rhamnopyranoside (6; multinoside A). Anti-oxidative and inhibitory activities on nitric oxide (NO) and prostaglandin E2 production in interferon-γ (INF-γ) and lipopolysaccharide (LPS)-activated RAW 264.7 cells in vitro (COX-2) of the isolated compounds were evaluated. Compounds 1, 5, and 6 exhibited potent anti-oxidative activity in the DPPH radical scavenging assay with IC50 values of 57.2, 59.4, and 54.3 μg/mL respectively. The positive control, ascorbic acid, had an IC50 of 55.5 μg/mL. Compounds 1, 5, and 6 also reduced COX-2 levels in a dose dependent manner with IC50 values of 10.2, 8.7, and 9.6 μg/ mL respectively, with the positive control, indomethacin, having an IC50 of 5.1 μg/mL. All six compounds inhibited NO production in a dose dependent manner with IC50 values of 35.1, 42.8, 40.0, 44.8, 43.7, and 43.9 μg/mL respectively, while the positive control, L-NMMA, had an IC50 of 42.1 μg/mL.

『금사(金史)』「신정하사의주(新定夏使儀注)」의 의의와 특징

( Sung Kyu Kim ) 성균관대학교 대동문화연구원 2013 大東文化硏究 Vol.87 No.-

금은 1225년 경에 신하국이던 서하와 형제관계를 맺고 그에 맞는 사절 의례를 제정하였다. 동아시아에서 점차 패자로서의 지위를 상실하게 된 금은 어쩔 수 없이 대외정책을 수정해야 했고, 서하와도 그 관계를 ``從``(君臣관계)에서 ``橫``(형제관계)으로 선회시켜야 했는데, 이것은 동시에 금조가 세계의 중심으로 자처하던 화이관의 파탄을 의미하였다. 이에 맞추어 서하에 대한 새로운 외교 의례가 마련되었고, 그 결과 「新定夏使儀注」(이하 「儀注」)가 제정되어 『金史』(권38 禮11)에 그 내용이 傳存한다. 다만 「儀注」제정으로부터 서하는 불과 2년 뒤에 멸망하기 때문에 양국이 형제관계를 유지한 것은 3년을 넘지 않으며, 따라서 「의주」가 金의 宮中에서 실제로 연출된 기회도 많지 않았다. 그럼에도 불구하고 「의주」의 연구 가치와 의의가 매우 큰 점은 강조되어야 할 것이다. 10~13세기 동아시아 각국에서 연출된 외교 의례(賓禮)는 宮中 의례를 중심으로 하며, 사료에도 외국사의 동향은 거의가 이 부분을 통해 나타난다. 하지만 외국사는 상대국에 체류하는 동안 客館을 숙소로 삼아 궁전에 출입할 뿐 아니라, 자신을 찾아오는 상대국 관원들과도 교류하는 등 客館에서 보내는 시간이 가장 길었고, 또 거기서도 다양한 의례가 연출되었다. 객관이야 말로 외국사가 現地에서 어떠한 활동을 했는지 들여다볼 수 있는 중요한 매개이지만, 당은 물론 송이나 요 측의 사료에는 그 정보가 제한적인 것에 반해, 유독 「의주」는 그 정황을 전하는 설명이 많으며, 이 점에서 사료로서의 가치가 크다. 여기서는 특히 숙소에 入館한 西夏使의 일정이 제1일차부터 귀국에 오르는 제9일차까지 일자별로 소개되어 있어 그 활동의 大槪를 파악하는데 매우 유익하다. 「의주」는 금 말기 아주 짧은 기간 동안 유지된 서하와의 새로운 관계 속에서 만들어졌지만, 내용의 대부분은 그 이전부터 서하사에게 적용되어 오던 것을 다시 편집한 것이 많았다고 생각된다. 비록 ``군신``에서 ``형제``로 관계의 格이 바뀌었다 해도 금의 西夏使에 대한 응대 방식에 근본적인 변화가 생겨난 것은 아니다. 또한 「의주」에는 금이 서하는 물론 기타 고려와 송 등의 외국사에게도 적용했을 일반적인 내용이 다수 포함되었을 것이며, 나아가 「의주」를 통해서는 송이나 요, 고려 등 기타 동아시아 왕조에서도 베일에 싸인 객관의 정황을 추정하는 단서를 제공한다고 보인다. 본문에서는 이상과 같은 의의를 갖는 「의주」를 분석해 金에 입국한 서하사가 어떠한 일정을 보냈는지를 확인하고, 또 체류 중에 그들이 통과한 여러 의례와 활동에 어떠한 원칙과 특징이 있는지를 발견해 정리할 것이다. In 1225 year, Jin(金) Dynasty had established diplomatic ties with Xi-xia (西夏) as ``brotherly relationship``. This was a result of Jin``s losing of a global hegemony in East Asia which it had been occupied by Jin for long time. And according to these changes, Jin could not help preparing a new type of diplomatic protocol for Xi-xia based on it``s status and as a result ``Xindingxiashiyizhu``(新定夏使儀注, this will be called as ``Yizhu`` below) have become appeared in Jinshi(金史). The ``Yizhu``, however, had not many chances to be performed at Jin``s palace because Jin dynasty itself was destroyed 2 years after. In spite of it``s short duration, we cannot stress enough that ``Yizhu`` have enough reason to be analyzed because it contains many kind of activities of Xi-xia envoys while their staying in Huitongguan(會同館) where was known as accommodation for foreign envoys. While the inside informations of the accommodation of Song or Liao dynasties were not enough clear to see how it was, we can access more important inside informations on Jin``s Huitongguan by a method of analyzing ``Yizhu``. In addition, ``Yizhu`` can be estimated that it contain general rules applied to foreign envoys including Goryo(高麗) as well as Xi-xia. In this essay, I could make sure the daily schedule of Xi-xia envoys and analyzied some court rituals Xi-xia envoys participated during their staying in Jin.

Internal Iliac Artery Ligation with Pad Packing for Hemodynamic Unstable Open Comminuted Sacral Fracture

( Sung Kyu Kim ),( Yun Chul Park ),( Young Goun Jo ),( Wu Seong Kang ),( Jung Chul Kim ) 대한외상학회 2017 大韓外傷學會誌 Vol.30 No.4

A 52-year-old man experienced blunt trauma upon falling from a height of 40 m while trying to repair the elevator. The patient’s systolic blood pressure and hemoglobin levels were 60 mmHg and 7.0 g/dL, respectively, upon admission. A large volume of bloody discharge was observed in the open wound of the perianal area and sacrum. A computed tomography scan revealed an open comminuted sacral fracture with multiple contrast blushes. He underwent emergency laparotomy. Both internal iliac artery ligations were performed to control bleeding from the pelvis. Protective sigmoid loop colostomy was performed because of massive injury to the anal sphincters and pelvis. Pad packing was performed for a sacral open wound and perineal wound at the prone position. After resuscitation of massive transfusion, he underwent the second operation 2 days after the first operation. The pad was removed and the perineal and sacral open wounds were closed. After the damage-control surgery, he recovered safely. In this case, the hemodynamically unstable, open comminuted sacral fracture was treated safely by internal iliac artery ligation with pad packing.

Tri-axial Core Design of a Distribution System Class HTS Power Cable

Sung-Kyu Kim,Sun-Kyoung Ha,Minwon Park,In-Keun Yu,Sangjin Lee,Kideok Sim 보안공학연구지원센터 2012 International Journal of Control and Automation Vol.5 No.3

Effect of Taurine and Orotic Acid on Liver and Serum Lipid Contents of Mouse

Sung-Kyu Kim,Jae-Young Cha,Young-Su Cho 한국토양비료학회 2000 한국토양비료학회 학술발표회 초록집 Vol.2000 No.5

Harmonic Current Based Loss Characteristics Analysis of HTS DC Model Cable Using Calorimetric Method

Sung-Kyu Kim,Seokho Kim,Jin-Geun Kim,Minwon Park,In-Keun Yu,Yoon Hyuck Choi,Haigun Lee IEEE 2012 IEEE transactions on applied superconductivity Vol.22 No.3

<P>Because the HVDC converter connected to an HTS DC power cable generates harmonics that cause an additional power loss in the DC cable, loss characteristics of the HTS DC power cable need to be analysed for practical applications to the HVDC system. A miniaturized HVDC thyristor converter and 2 m length HTS DC cable made of YBCO HTS wire were used to measure the power loss in the HTS DC power cable. The loss characteristics of the HTS DC model cable were analysed using the finite elements method (FEM). The power loss of the DC current which contains harmonics was measured using the calorimetric method. The experiment and FEM analysis results were compared to confirm that the harmonic current induced by the HVDC converter influence the power loss in the HTS DC cable.</P>