주파수 가변 고속 디지털 MRI 모뎀 RF부 설계와 구현

김용철,박현대,김대진 전남대학교 전자통신기술연구소 2001 전자통신기술논문지 Vol.4 No.1

In this paper, we designed and made RF block of variable frequency digital modem for high speed MIRI system that can support not only multi-nuclei system but also any magnetic intensity(1.0T~3.0T). We executed simulation of fixed frequency digital modem using fixed band pass filter(BPF), variable frequency digital modem using variable band pass filter(tunable filter). Based on these simulations, variable band pass filter(tunable filter) named Micropole is ordered and manufactured. We designed and made RF block of variable frequency digital modem for high speed MRI system using variable band pass filter(tunable filter). And then we tested this board using PC and function generator and observed the output spectrum using spectrum analyzer. These spectrums are very clear and wide bandwidth about 500KHz and the level of main spectrum is 60~70dB more than harmonics or spurious. This difference of level is available for MRI system.

야스쿠니(靖国) : 아시아태평양전쟁기 일본의 정신적 허브

김용철 한국일본학회 2018 日本學報 Vol.0 No.114

이 논문은 아시아태평양전쟁기 야스쿠니신사의 성격을 논한 것이다. 기존의 논의에서는 ‘군국주의의 상징’이나 ‘블랙홀’과 같은 간명한 규정은 있었지만, 당시 일본의 주요집단이나 존재 사이에서 야스쿠니신사가 어떤 기능을 수행했고 어떤 의미를 갖고 있었는지, 그리고 그와 같은 기능이나 의미를 고려했을 때 그것의 성격이 어떠했는지에 관한 논의는 미흡한 상태에 있다. 바로 그 이유 때문에 보다 새로운 시각에서 당시 야스쿠니신사의 성격을 조명할 필요가 있다. 야스쿠니신사는 메이지시대 초기 무진전쟁 전사자의 합사공간으로 출발하여 오락과 여가의 공간으로 대중들에게 친숙하여졌고, 청일전쟁 러일전쟁을 지나며 국가주의와의 결합을 강화해갔으며 아시아태평양전쟁기에는 이벤트공간으로서의 성격과 함께 상징적 토포스로서 정신적 허브의 기능을 수행하였다. 표면적으로는 별격관폐사라는 국가신도의 한 기관에 불과했지만, 천황과 국가를 위해 전사한 전사자의 합사공간이었고 상징적 토포스로서 군인과 천황, 후방의 국민을 연결하는 공간이었다. 천황이 임시대제나 예대제에 행차할 때에는 천황가와 야스쿠니신사가 연결됨으로써 이세신궁을 대신하는 토포스가 되었고, 군인이 야스쿠니를 참배할 때에는 천황, 국가와 연결되었으며 후방의 국민이 참배할 때 역시 천황, 국가, 그리고 전사자들과 연결되었다. This essay discusses the character of Yasukuni Shirine(靖国神社) during the Asia-Pacific War. Although previous research presented discourses such as “the symbol of militarism” or “blackhole” it is difficult to establish the function and meaning thereof among the main groups of Japan and the Emperor during the era of the Asia-Pacific war. Therefore, it is necessary to investigate Yasukuni from another point of view. Yasukuni Shirine was started as a space in which to collectively enshrine those who died during the Boshin War(戊辰戦争). The shrine became familiar as place of leisure and public entertainment. It consolidated the combined nationalism resulting from the First Sino-Japanese and Russo-Japanese War. Eventually, it became a spiritual herb, and functioned as symbolic tophus with the character of space for events during the Asia-Pacific War. On the surface, it was a kind of institute of the National Shinto, with the grade of Bekkaku Kanpei-sha(別格官幣社), it was a space to collectively enshrine those who died in the war for the Japanese Emperor and state, and connected individual soldiers, the Emperor, and people on the home front as a symbolic tophos. When the Emperor participated in the ceremony of Yasukuni, and it was connected with the Emperor's family, the place came to be the tophos that replaced the Ise Grand Shirine(伊勢神宮), the soldiers who worshipped Yasukuni, connected with the Emperor and state, and the nation on the home front who were also connected with the Emperor, state, and war dead.

경천호에서의 수중 음향 통신 채널 환경 분석

김용철,안종민,이호준,이상국,정재학 한국음향학회 2019 韓國音響學會誌 Vol.38 No.1

본 논문은 호수에서의 원활한 수중음향통신을 위해 호수의 수중 채널 환경에 따른 통신 변수들을 도출하였다. 본 논문에서는 실제 호수 환경에서의 두 번의 실험을 통하여 상관 시간과 상관 대역폭을 산출하였다. 두 번의 실험에서채널 추정과 비트오류율 산출을 위해 chirp 신호와 BPSK(Binary Phase Shift Keying) 신호를 전송하였고, 각각의 실험은 송신단과 수신단과의 거리가 300 m에서 400 m일 때와 500 m에서 600 m일 때 진행하였다. 첫 번째 실험과 두번째 실험에서 각각 산출한 상관 시간은 175 msec와 340 msec이고, 상관 대역폭은 10 Hz와 5.71 Hz이다. 동기 신호의길이와 프레임 내 파일럿 신호의 간격이 상관 시간보다 짧은 경우에만 동기화와 비트오류율 성능이 더 우수하여 산출한 실험 결과가 적절함을 확인하였다. This paper estimated communication parameters according to underwater channel environment of lake for underwater acoustic communication. This paper calculated coherence time and coherence bandwidth through two experiments in actual lake environments. In both experiments, the chirp signal for channel estimation and the BPSK (Binary Phase Shift Keying) signal for calculating the bit error rate were transmitted. In each experiment, the distance between transmitter and receiver was 300 m to 400 m, and 500 m to 600 m. The coherence times calculated in experiment 1 and experiment 2 are 175 msec and 340 msec, and the coherence bandwidths are 10 Hz and 5.71 Hz, respectively. It is confirmed that the experimental results are more appropriate because the synchronization and the bit error rate performance are better only when the length of the synchronization signal and the interval of the pilot signal in the frame are shorter than the coherence time.

Intravascular Ultrasound-Guided Percutaneous Coronary Intervention with Drug-eluting Stent for Unprotected Left Main Disease via Left Snuffbox Approach

김용철,정명호,김인나,김민철,심두선,홍영준,김주한,안영근 대한심장학회 2018 Korean Circulation Journal Vol.48 No.6

순천만국가정원의 역사인물 스토리텔링과 서사창작 - <순천만국가정원몽유록>

김용철 순천대학교 남도문화연구소 2017 南道文化硏究 Vol.0 No.32

이 논문은 순천만국가정원을 대상으로 어떤 서사문학작품을 창작할 수 있는가 하는 것을 보여주기 위한 하나의 예로 쓰여진 것이다. 필자는 이를 위해 한국 고전서사 장르 중 몽유록의 형식으로 순천만국가정원을 그려내는 방법을 택하였다. 즉 <순천만국가정 원몽유록>이라는 작품을 짓는다고 가정하고 작품 구상을 해설하는 방식으로 서술하였 다. <순천만국가정원몽유록>이라는 서사작품을 창작하는 의의를 설명하고 작품 창작과 정에서 순천만국가정원이라는 배경 아래 인물과 사건을 만들어내는 과정을 설명하는 것이다. 필자는 <순천만국가정원몽유록>이라는 서사작품을 몽유록의 구조에 따라 구성하였 다. <순천만국가정원몽유록>에는 총 8명의 인물이 등장한다. 지수는 등장인물이자 서술 자이다. 남해신, 용산신, 동천신은 순천만국가정원을 둘러싼 자연환경을 신격으로 의인 화한 것이다. 이 네 인물이 합의하여 순천만국가정원을 지키는 성황신으로 박영규, 정소, 김광수, 앵무어미라는 네 명의 인물을 평가하고 좌정시키게 된다. 이 논문은 순천만국가 정원과 관련된 역사인물들을 성황신으로 좌정시킴으로써 순천만국가정원에 역사적 무게 를 더해주려는 의도에서 씌어진 것이다. This article is written as an example to demonstrate how to create an narrative writing for Suncheon Bay National Garden. I describe the structure of the work associated with the structure of a mongyurok genre of Korean classical literature. I suppose to write the work of “Mongyurok of Suncheon Bay National Garden” and describe the concept and process of narrative writing. I explain the significance of creating an narrative titled “Mongyurok of Suncheon Bay National Garden” and describe the process of creating characters, incidents, backgrounds of “Mongyurok of Suncheon Bay National Garden”. I describe “Mongyurok of Suncheon Bay National Garden” in accordance with the structure of Mongyurok. There are eight figures in “Mongyurok of Suncheon Bay National Garden”. The Jisu is a character and narrator. Gods of Namhae, Yongsan, and Dongcheon are the natural surroundings of Suncheon Bay National Garden. They agree upon to honor the four figures – Bak-Yeonggyu, Jeong-So, Kim-Gwangsu, and Aengmu’s mother. This article is written in an attempt to add historical weight to Suncheon Bay National Garden to set down figures associated with Suncheon Bay National Garden.

[유기성 자원화] 폐폴리우레탄 재활용 기술개발

김용철,김진국,최겸우,김병수 한국폐기물자원순환학회 2005 한국폐기물자원순환학회 학술대회 Vol.2005 No.1

고희동의 회화와 전통회귀

김용철 한국미술이론학회 2018 미술이론과 현장 Vol.0 No.26

This paper explores the phase in Ko Hui-dong’s artistic career marked by his return to traditional painting in the mid-1920s. The essay examines how this return exhibits the two noticeable features of stylistic fusion and traditionalism, and then, argues that this characteristic reflects what is known as Nanga painting, a school of Japanese painting. To examine this parallel, the essay first explores the aspect of stylistic fusion in Ko Hui-dong’s painting, in which the traditional feature of calligraphy is mixed with the technique of realistic representation. There is also another tendency to rely on a more traditional approach defined by line-centered depiction and multiple perspectivism often found in imaginary landscape painting. By the 1940s, Ko Hui-dong’s involvement with Nanga painting was evident when he became an organizing member of Society of Nanga Painters in colonial Korea with Yi Sang-beom, Noh Su-hyun, Byun Gwan-sik. In short, his return to traditionalism spells out a spiritual as well as stylistic alliance with Nanga painting rooted in the history of Japanese modern arts in incorporating traditionalism and realism. 한국 최초의 서양화가인 고희동의 회화는 1920년대 중반 서양화에서 전통회화로 회귀하였다. 이논문에서는 그가 서양화에서 전통회화로 회귀하게 된 과정을 검토한 다음 전통회귀 이후 그가 남화가로 분류된 사실에 주목하여 그 배경과 의미를 규명하였다. 고희동의 회화가 전통으로 회귀한 이후 조형표현에 나타난 특징은 두 가지 즉, 서양화법의 특징을 도입하여 절충적인 특징을 드러내거나 관념산수의 전통을 이으며 필선 중심의 묘사나 단일시점이 아닌 분절적인 시점을 설정하는 특징을 보였다. 특히 1940년대에 고희동이 조선남화연맹의 창립 회원으로서 활동하며 이상범, 노수현, 변관식 등과함께 남화가로 활동한 사실은 그의 전통회귀가 일본인의 동아시아회화사 인식에 바탕을 둔 남화를 그리는 화가로 분류되었음을 의미한다.

Current status of acute myocardial infarction in Korea

김용철,안영근,조명찬,김종진,김영조,정명호 대한내과학회 2019 The Korean Journal of Internal Medicine Vol.34 No.1

Coronary artery disease, especially acute myocardial infarction (AMI), is a leading cause of death in the Asia-Pacific region. The Korea Acute Myocardial Infarction Registry (KAMIR) is the first nationwide, prospective, multicenter registry of Korean patients with AMI. Since the KAMIR first began in November 2005, more than 70,000 patients have been enrolled, and 230 papers have been published (as of October 2018). Moreover, published data from the KAMIR have revealed different characteristics from those of Western AMI registries regarding risk factors, interventional strategies, and clinical outcomes. As a result, the KAMIR study has improved the outcomes of percutaneous coronary intervention and reduced mortality. We propose the use of the KAMIR score in the prediction of 1-year mortality. Using data from the KAMIR, we provide an overview of the current status of AMI in Korea, including trends in demographic characteristics, risk factors, medications, treatment strategies, and clinical outcomes.

Feasibility of Coronary Angiography and Percutaneous Coronary Intervention via Left Snuffbox Approach

김용철,Youngkeun Ahn,Inna Kim,Doo Hwan Lee,Min Chul Kim,Doo Sun Sim,Young Joon Hong,Ju Han Kim,Myung Ho Jeong 대한심장학회 2018 Korean Circulation Journal Vol.48 No.12

Background and Objectives Feasibility of coronary angiography (CAG) and percutaneous coronary intervention (PCI) via left snuffbox approach is still concerned. We aimed to investigate efficacy and safety of the left snuffbox approach for CAG and PCI. Methods Left snuffbox approach was tried in 150 patients who planned to perform CAG or PCI for suspected myocardial ischemia between 1 November 2017 and 31 March 2018. Results Success rate of radial artery (RA) cannulation via snuffbox approach was 88.0% (n=132). Among 132 individuals, 58 (43.9%) acute coronary syndrome (ACS) patients were included. The diameter of snuffbox RA was significantly smaller than conventional RA (2.57 mm vs. 2.72 mm, p<0.001) from quantitative computed angiography of 101 patients. However, CAG via snuffbox approach by 6 French sheath was successfully performed in all 132 patients. In addition, there was significant correlation between the snuffbox and conventional RA diameter (r=0.856, p<0.001). In 42 PCI cases, including 25 patients with acute myocardial infarction (AMI), the success rate of PCI via snuffbox approach was 97.6% (n=41). Intravascular imaging-guided PCI was performed in 8 (19.5%) patients and multi-vessel PCI in 4 (9.8%) cases. Regarding vascular complication, forearm swelling with bruising, not requiring surgery or transfusion, occurred in 2 (4.9%) PCI cases. Conclusions Left snuffbox approach is suitable for CAG and PCI compared with the conventional radial approach.

효용함수 연구

김용철 용인대학교 산업경영연구소 2003 산업경영논총 Vol.9 No.-

Under certain assumption we know that the prospect facing a person has a numerical value called utility, and that we make those decisions for which ours prospects would have as large a utility as possible. Generally speaking, this is easier said than done, but, in many applications, certain simple properties of utility make it feasible for one to make intelligent decisions. The purpose of this paper is introduced to the use for the utility function in multi-attribution utility theory. The utility function is extended by the various probability of success for a interested data. We discussed the generalized utility function with a attribution of data.