Antibiotics in Surgical Patients

Youngki Hong 대한외과학회 2021 대한외과학회 학술대회 초록집 Vol.2021 No.11

Recent progress in high-mobility thin-film transistors based on multilayer 2D materials

Hong, Young Ki,Liu, Na,Yin, Demin,Hong, Seongin,Kim, Dong Hak,Kim, Sunkook,Choi, Woong,Yoon, Youngki IOP 2017 Journal of Physics. D, Applied Physics Vol.50 No.16

<P>Two-dimensional (2D) layered semiconductors are emerging as promising candidates for next-generation thin-film electronics because of their high mobility, relatively large bandgap, low-power switching, and the availability of large-area growth methods. Thin-film transistors (TFTs) based on multilayer transition metal dichalcogenides or black phosphorus offer unique opportunities for next-generation electronic and optoelectronic devices. Here, we review recent progress in high-mobility transistors based on multilayer 2D semiconductors. We describe the theoretical background on characterizing methods of TFT performance and material properties, followed by their applications in flexible, transparent, and optoelectronic devices. Finally, we highlight some of the methods used in metal-semiconductor contacts, hybrid structures, heterostructures, and chemical doping to improve device performance.</P>

Case Analysis of the Effects of Nucleoplasty and Chemonucleolysis on the Intervertebral Disc

Youngki Hong 대한스포츠물리치료학회 2018 정형스포츠물리치료학회지 Vol.14 No.2

Purpose: This study was evaluated the effects of nucleoplasty and chemonucleolysis, as interventional treatments for herniated intervertebral disc disease, on spinal tissues. Methods: Nucleoplasty using plasma beam and chemonucleolysis with collagenase were conducted on the spinal motion segments that were dissected from of human cadaver spine under fluoroscopic guidance. After the procedure, the intervertebral discs were transected, and the changes in gross findings were examined. Subsequently, the influence of the procedure on the nucleus pulposus, annuls fibrosus, and endplate was analyzed through a pathologic examination. Results: Nucleoplasty was confirmed to eliminate the local range of tissues in nucleus pulposus according to the procedure tract and to not affect other tissues. In chemonucleolysis, we found that collagenase diffused from the surgical site within the nucleus pulposus and was not present in the annulus fibrosus and endplate. Conclusions: The clinically-used interventional treatments that were investigated here were not found to do not cause additional damage to areas other than those targeted.

Surveillance and Prevention of Surgical Site Infection in Surgical Prosthesis

Youngki Hong 대한외과학회 2022 대한외과학회 학술대회 초록집 Vol.2022 No.11

Evaluation of the resection effi ciency and safety of an enhanced power plasma generator using cadaveric intervertebral discs

Youngki Hong,Sung-Young Yoon,Sangho Sohn,Nack Hwan Kim,Yushin Kim,Sangheon Lee 대한의용생체공학회 2023 Biomedical Engineering Letters (BMEL) Vol.13 No.1

Plasma energy has been used to provide minimally invasive interventional treatment for spinal problems. However, this procedure has been used for limited indications mainly because of its small resection range. To overcome this problem, we designed the enhanced power plasma device. This device seeks to maximize the resection area by modifying the electrode arrangement and enhancing the maximum electric power. The purpose of this study is to assess the efficiency and safety of this newly designed plasma generator, a device for percutaneous disc decompression. We performed an intradiscal procedure on 7 fresh human cadaver lumbar spine specimens using the enhanced power plasma under C-arm fluoroscopic guidance at various voltages. As a result, the volume of the removed area was proportional to the applied magnitude of the electric power level. In particular, under the high-power level condition after 500 s treatment, nearly the entire nucleus pulposus was eliminated. The generated plasma density also tends to grow along with the given electric power. The highest level of temperature rise did not exceed the level that would lead to degeneration in the collagen tissue of the intervertebral disc. Histopathologic examination also demonstrated that there was no thermal damage to the surrounding neural tissues. In conclusion, we speculate that the concepts of this newly designed enhanced plasma generator could be applied to remove huge disc materials without thermal or structural damage to the adjacent target tissues in future spine clinics.

Incidence and Characteristics of Colorectal Cancer except Adenocarcinoma

Youngki Hong,Yoon Jung Choi,Jung Gu Kang 대한종양외과학회 2020 대한임상종양학회 학술대회지 Vol.2020 No.7

태권도 품새에 대한 실증적 고찰: 공수도, 고무도와의 관련성을 중심으로

홍영기 ( Youngki Hong ) 대한무도학회 2020 대한무도학회지 Vol.22 No.4

이 연구의 목적은 실증적 관점에서 품새의 형성 과정을 탐구하고, 그것을 바탕으로 품새 동작의 기술적 의미를 규명하는 것이다. 이를 위해 태권도의 기원과 품새가 만들어진 과정에 대한 문헌자료를 분석하였다. 그 결과 태권도의 품새는 공수도의 형(型)을 기반으로 제작되었으며, 공수도의 형은 오키나와의 무기술인 고무도(古武道)와 기술적으로 연계되어 있음을 확인하였다. 따라서, 태권도의 품새 기술에는 순수한 맨손 무술의 원리 이외에도 고무도에 기반한 무기술의 원리가 내재되어 있을 것이라 추정된다. 이러한 인식을 바탕으로, 논자는 품새 동작의 기술적 의미를 파악하기 위해선 맨손 무술의 관점 뿐 아니라 무기술의 관점도 함께 고려되어야 한다고 생각한다. 이러한 관점의 확장을 통해 품새 동작의 기술적 의미는 보다 보다 실증적 차원에서 보다 선명하게 드러날 수 있을 것이다. The purpose of this study is to investigate the formation of Poomsae from an empirical point of view and with this information as a basis, to research about technological implication of the Poomsae movement. For this purpose, I conducted a literature review about the origin of Taekwondo and the development of Poomsae. The research revealed that Taekwondo Poomsae originated from Karate-do Kata, while Karate-do Kata was technically linked to Komudo, an armed martial art of Okinawa. Presumably, in addition to the principle of pure unarmed martial arts, Taekwondo Poomsae technique contains the principle of armed martial arts based on Komudo. Thus, in order to grasp the technological implication of the Poomsae movement, it might be necessary to consider the viewpoint of armed martial art as well. Through the expansion of the viewpoint in such way, the tecnological implication of the Poomsae movement could be revealed more clearly in a more empirical perspective.

일본의 ISOBUS 기술동향

홍영기 ( Youngki Hong ) 한국농업기계학회 2023 상주농업기계박람회 심포지엄 Vol.2023 No.0

경부통증과 경추곡률의 관련성에 관한 연구

홍영기(Youngki Hong) 한국자료분석학회 2018 Journal of the Korean Data Analysis Society Vol.20 No.1

이 논문의 목적은 경부통증과 경추곡률의 관련성을 알기 위함이다. 만성 경부통증을 지닌 스물 두 명의 자원자들이 실험에 참여하였다. 참여자들은 시각상사척도에 근거한 통증의 정도에 따라, 저 통증군과 고 통증군의 두 군으로 분류되었다. 참여자들 경추의 시상면 방사선사진이 중립, 전굴, 신전자세로 촬영되었다. 방사선 사진에 나타난 경추뼈들 간의 후면접선을 연결하는 방법으로 경추의 전체 각도와 각 분절들의 각도가 측정되었다. 두 군은 1) 중립자세 일 때의 각도 2) 전굴 시 중립자세로부터 변화된 각도 3) 신전 시 중립자세로부터 변화된 각도라는 세 가지 측면에서 서로 비교되었다. 그 결과, 특히 신전 시에 변화된 전체 각도가 고 통증군에서 작았고, 분절별 비교에선 C3/4 와 C6/7 의 변화된 각도가 고 통증군에서 작았다. 결론적으로, 통증의 강도는 방사선 소견상 경추의 신전 시 변화되는 각도의 크기와 의미 있는 관련성이 관찰되었다. 그리고 본 실험의 분절 별 비교에서 다른 분절에 비해 경직이 잘 발생하는 것으로 관찰된 분절들에 대해선, 스트레칭이나 견인 같은 재활치료 시 보다 특화되고 집중된 접근이 이루어져야 할 것이다. The purpose of the study was to investigate the relationship between cervical pain and cervical spinal curvature. Twenty-two volunteers were divided into two groups which are low pain group and high pain group, according to the visual analogue scale. Sagittal roentgenographs of the cervical spine in neutral, flextion and extension posture were taken. By means of connecting the posterior tangent line of cervicalspine, global and segmental angles of cervical spine were measured. Three factors were compared between the two groups of subjects: 1) the angle of neutral posture 2) the alteration of angle when the posture changes from neutral to flexion 3) the alteration of angle when the posture changes from neutral to extension. As a result, especially, the global and segmental alteraion of angles related to extension posture was smaller in high pain group. Consequently, roentgenographic findings show that the degree of pain is particularly related with the degree of change in extension angle. Through this experiment, some segments were found to stiffen more often than other segments. Therefore, when a patient undergoes rehabilitation treatment such as stretching or traction, more concentrated and specialized approach is recommended to these segments.

SSD 와 HDD에 대한 리눅스 I/O Subsystem의 성능평가

홍영기(Youngki Hong),이우중(Woojoong Lee),박찬익(Chanik Park) 한국정보과학회 2008 한국정보과학회 학술발표논문집 Vol.35 No.2

본 논문에서는 리눅스 IO Subsystem 내 Page cache와 File system 계층이 HDD와 SSD의 성능에 어떠한 영향을 미치는지 성능 평가를 통해 알아보고 평가 결과를 분석하였다. 이를 위해 두 계층에서 다양한 워크로드를 통해 HDD와 SSD의 성능을 평가하였다. 실험 결과를 통해, 현재의 IO subsystem 내 Page cache 와 File system 계층이 HDD의 물리적인 특성을 이용하여 IO 성능 향상을 보이고 있지만, 이러한 특징들이 SSD의 IO 성능에는 크게 영향을 미치지 않는 다는 것을 알 수 있었다.