거대성 임파절 비후 : 1예 보고 One Case Report

이희종,김영덕,장석효 최신의학사 1987 最新醫學 Vol.30 No.9

New Media 산업의 현황과 장래

이희종,Lee, Hui-Jong 한국전자정보통신산업진흥회 1984 電子振興 Vol.4 No.6

플랫폼 노동자 ‘보호’ 법안인가

이희종 한국비정규노동센터 2021 비정규 노동 Vol.149 No.-

신생아 집중치료실에서 극단 저체중 미숙아의 동맥관 개존증 폐쇄술을 위한 remifentanil과 sevoflurane의 사용 경험 -증례 보고-

이희종,정미애,최진화,조주원 대한마취통증의학회 2010 Anesthesia and pain medicine Vol.5 No.4

Surgical ligation of PDA is an effective treatment for symptomatic infants who do not respond to treatment with indomethacin. Transfer of unstable infants to the operating room has been shown to be associated with various problems. Thus, we describe the anesthetic management of 5 extremely low birth weight (ELBW) infants who underwent surgical ligation of PDA in a neonatal intensive care unit (NICU). General anesthesia was induced by ketamine 1 mg/kg IV. Rocuronium was used for muscle relaxation. Anesthesia was maintained with continuous infusion of remifentanil 0.15−0.4 ug/kg/min with oxygen (in 2 cases) or continuous infusion of remifentanil 0.05−0.1 ug/kg/min and 0.4−1.0 vol% sevoflurane with oxygen (in 3 cases). It was safe and effective to perform bedside PDA ligation in the NICU. We describe the successful use of remifentanil with sevoflurane or remifentanil alone in 5 extremely low birth weight infants undergoing PDA ligation.

원전 증기발생기 와전류검사 장치의 전기적 특성 측정

이희종,조찬희,유현주,문균영,이태훈,Lee, Hee-Jong,Cho, Chan-Hee,Yoo, Hyun-Joo,Moon, Gyoon-Young,Lee, Tae-Hun 한국비파괴검사학회 2013 한국비파괴검사학회지 Vol.30 No.3

원전 증기발생기는 원자로 냉각재 계통에서 발생한 열에너지를 터빈 계통의 주급수에 전달하여 터빈을 회전시키기 위한 증기를 생산하는 일종의 열교환기이다. 증기발생기 전열관의 손상은 증기발생기의 구조적 및 누설 건전성 유지 능력을 저해시키기 때문에 주기적으로 와전류검사를 수행하여 전열관의 건전성을 평가한다. 증기발생기 전열관의 건전성 평가는 보통 원자로 연료 재장전 기간 중에 수행된다. 현재 국내 증기발생기 전열관에 적용되는 와전류검사는 KEPIC 및 ASME 코드 요건에 따라 수행되며, 와전류검사 수행에 필요한 검사 시스템은 와전류검사 장치와 수집된 신호를 평가하기 위한 평가 프로그램으로 구성된다. 검사에 적용되는 와전류검사 시스템을 구성하는 핵심기기인 와전류검사 장치는 ASME 및 KEPIC 코드에서 총 고조파 왜곡율, 입출력 임피던스, 증폭기 직선성 및 안정성, 위상 직선성, 대역폭 및 복조필터 응답, 디지털 변환, 채널 간섭 등과 같은 전기적 특성을 측정하도록 규정하고 있다. 이에 따라 본 논문에서는 국내 최초로 개발한 원전 증기발생기 와전류검사 장치의 전기적 특성 측정을 위한 ASME 및 KEPIC 코드 요건을 설명하고, 이 요건에 따른 증기발생기 와전류검사 장치의 전기적 특성의 측정 결과를 제시하였다. A steam generator in nuclear power plant is a heatexchager which is used to convert water into steam from heat produced in a nuclear reactor core, and the steam produced in steam generator is delivered to the turbine to generate electricity. Because of damage to steam generator tubing may impair its ability to adequately perform required safety functions in terms of both structural integrity and leakage integrity, eddy current testing is periodically performed to evaluate the integrity of tubes in steam generator. This assessment is normally performed during a reactor refueling outage. Currently, the eddy current testing for steam generator of nuclear power plant in Korea is performed in accordance with KEPIC & ASME Code requirements, the eddy current testing system is consists of remote data acquisition unit and data analysis program to evaluate the acquired data. The KEPIC & ASME Code require that the electrical properties of remote data acquisition unit, such as total harmonic distortion, input & output impedance, amplifier linearity & stability, phase linearity, bandwidth & demodulation filter response, analog-to-digital conversion, and channel crosstalk shall be measured in accordance with the KEPIC & ASME Code requirements. In this paper, the measurement requirements of electrical properties for eddy current testing instrument described in KEPIC & ASME Code are presented, and the measurement results of newly developed eddy current testing instrument by KHNP(Korea Hydro & Nuclear Power Co., LTD) are presented.

The use of 3 sugammadex out of 5 reversal of during recovery of rocuronium-induced neuromuscular blockade in a patient with post-tonsillectomy hemorrhage -a case report-

이희종,김태연,이정혁,정미애,김교상 대한마취통증의학회 2014 Korean Journal of Anesthesiology Vol.67 No.1

Post-tonsillectomy hemorrhage (PTH) is the most frequent complication of tonsillectomy, and occasionally results in a lethal outcome. A 21-year-old man (height 180 cm, weight 95 kg) was scheduled for a bilateral tonsillectomy and uvulopalatopharyngoplasty for treatment of obstructive sleep apnea. He required 5 rounds of general anesthesia due to recurrent PTH. The anesthesiologist used sugammadex a total of 3 times to achieve the successful reversal of the deep neuromuscular blockade (NMB) induced by rocuronium. After sugammadex 2 mg/kg was administered, the NMB was reversed in 2 minutes each time. Re-administration of rocuronium within a short time interval after sugammadex may result in unpredictable effects of neuromuscular blocking agents. Sugammadex made it possible to perform a rapid, complete reverse when the residual block was maintained by an incomplete reversal of anticholinesterase.

와전류검사 기술을 적용한 가압중수로 원전 압력관 비파괴검사

이희종,최성남,조찬희,유현주,문균영,Lee, Hee-Jong,Choi, Sung-Nam,Cho, Chan-Hee,Yoo, Hyun-Joo,Moon, Gyoon-Young 한국비파괴검사학회 2014 한국비파괴검사학회지 Vol.27 No.4

중수로 원자로는 한 개의 원자로용기로 구성된 경수로와는 달리 약 380여개의 연료채널(fuel channel)로 구성되어 있다. 연료채널을 구성하는 압력유지 기기인 압력관(pressure tube)은 지르코니움 합금(Zr-2.5wt% Nb) 재질로서 치수는 내경이 103.4 mm, 두께가 약 4.19 mm, 길이가 6.36 m인 튜브 형태의 관이다. 압력관은 내부에 핵연료 다발과 냉각재가 내장되며 압력관의 기능은 연료를 지지하고 열수송 유체인 중수($D_2O$)를 이송한다. 압력관의 단순한 기하학적인 형상으로 인하여 자동화 비파괴검사가 가능하고 접근성이 우수하다. 연료채널은 경수로형 원전과 동일하게 설치전과 운전중에 원자력안전위원회 법령 요건에 따라 주기적으로 엄격한 비파괴검사를 수행하여 건전성을 확인한다. 연료채널의 주기적 비파괴검사에는 초음파탐상 및 와전류탐상검사 기법을 적용한 체적 비파괴검사 기술이 적용된다. 이중에서 와전류탐상검사 기법은 초음파탐상검사에서 검출된 결함의 확인을 위한 보충검사기술로 적용되고 있지만 표면결함에 대한 검출능이 초음파탐상검사 기법보다 우수한 장점을 가지고 있다. 본 논문에서는 압력관 내부 표면 비파괴검사에 적용되고 있는 와전류탐상검사 기술의 압력관 내면에 발생할 수 있는 결함의 검출 및 깊이 측정 특성에 대한 연구결과를 기술하였다. 즉, 와전류검사 기술은 압력관 내면에 발생할 수 있는 아주 미세한 결함을 매우 우수한 분해능으로 검출할 수 있으므로 초음파탐상검사 결과 확인을 위한 보충기술로서 매우 유용하지만, 결함의 깊이 측정은 오차가 매우 크게 발생하므로 결함 깊이 측정에는 적합하지 않고 오직 표면결함 검출에만 적용하는 것이 바람직하다. A pressurized heavy water reactor (PHWR) core has 380 fuel channels contained and supported by a horizontal cylindrical vessel known as the calandria, whereas a pressurized water reactor (PWR) has only a single reactor vessel. The pressure tube, which is a pressure-retaining component, has a 103.4 mm inside diameter ${\times}$ 4.19 mm wall thickness, and is 6.36 m long, made of a zirconium alloy (Zr-2.5 wt% Nb). This provides support for the fuel while transporting the $D_2O$ heat-transfer fluid. The simple tubular geometry invites highly automated inspection, and good approach for all inspection. Similar to all nuclear heat-transfer pressure boundaries, the PHWR pressure tube requires a rigorous, periodic inspection to assess the reactor integrity in accordance with the Korea Nuclear Safety Committee law. Volumetric-based nondestructive evaluation (NDE) techniques utilizing ultrasonic and eddy current testing have been adopted for use in the periodic inspection of the fuel channel. The eddy current testing, as a supplemental NDE method to ultrasonic testing, is used to confirm the flaws primarily detected through ultrasonic testing, however, eddy current testing offers a significant advantage in that its ability to detect surface flaws is superior to that of ultrasonic testing. In this paper, effectiveness of flaw detection and the depth sizing capability by eddy current testing for the inside surface of a pressure tube, will be introduced. As a result of this examination, the ET technique is found to be useful only as a detection technique for defects because it can detect fine defects on the surface with high resolution. However, the ET technique is not recommended for use as a depth sizing method because it has a large degree of error for depth sizing.

Optimal positive end-expiratory pressure during robot-assisted laparoscopic radical prostatectomy

이희종,김교상,정지선,심재철,최은선 대한마취통증의학회 2013 Korean Journal of Anesthesiology Vol.65 No.3

Background: Increased intra-abdominal pressure during laparoscopic surgery causes cephalad displacement of the diaphragm, resulting in the formation of atelectasis, which can be overcome by positive end-expiratory pressure (PEEP). The aim of this prospective study was to investigate the level of optimal PEEP to maintain adequate arterial oxygenation and hemodynamics during robot-assisted laparoscopic radical prostatectomy (RLRP). Methods: One hundred patients undergoing RLRP were randomly allocated to one of five groups (n = 20) (0, 3, 5, 7 and 10 cmH2O of PEEP). Hemodynamic variables and respiratory parameters were measured at baseline with the patient in the supine position; at 30 min, 1, 2, 3 and 4 h during CO2 insufflation with the patient in the post-Trendelenburg position; and after deflation in the supine position with increasing PEEP. Results: The PaO2 levels and alveolar-arterial difference in oxygen tension (AaDO2) were improved in patients with PEEPs compared with patients in whom PEEP was not used. The application of PEEP (10 cmH2O) resulted in higher PaO2 levels compared to those with lower PEEP levels, but excessive peak airway pressure (PAP) was sometimes observed. The application of a PEEP of 7 cmH2O resulted in similar PaO2 levels without causing excessive PAP. There was a significant difference in central venous pressure between the groups, but there were no significant differences in heart rate, mean arterial pressure or minute ventilation between the groups. Conclusions: A PEEP of 7 cmH2O is associated with the greater improvement of PaO2 and AaDO2 without causing excessive PAP during RLRP.

사회적 기업에 대한 재정지원 방안의 개선에 관한 연구

이희종,윤인하 한양법학회 2018 漢陽法學 Vol.29 No.4

Social enterprises can contribute to the society by diverse means, such as creating jobs, providing social services and improving environment. Of course, social enterprises cannot solve all the problems that may occur in a modern capitalistic society. However, social enterprises can supplement the weaknesses of modern capitalism, which may arise in the public and social areas such as welfare and environment. They in particular have business models that can benefit the socially vulnerable. Therefore, development of social enterprises can provide great opportunities in order for our society to achieve further advancement. However, most of Korean social enterprises are still in the level of small business. That’s why social enterprises rely heavily on government’s financial supports. Although we do not deny the need for governmental supports for social enterprises, excessive reliance on them would not help to raise the self-sufficiency of Korean social enterprises. Also, current financial plans for social enterprises cannot make sufficient effects because they support for too short periods. Increasing the duration of supporting for labor costs of social enterprises will result in supporting in the most needed time periods. In addition, current financial aid plans concentrate on supporting for only labor costs to employ the socially vulnerable. This may be a constraint on the recruitment of the labor force required by the social enterprises. Considering the characteristics of the industries related with social enterprises, it is necessary to apply differentiation to the social enterprises. In the long run, supports for social enterprises should be done by the private sector rather than by the central or local governments. To this end, a social stock exchange is needed to facilitate the financing of social enterprises. It would be easier to use the KONEX market for SMEs. It should be noted, however, that it is necessary to make sure that investors are aware of the risks and that investors should be limited only to social investors excluding ordinary investors, since investing in social enterprises is totally different from investing in stocks of ordinary corporations. Finally, it is naturally necessary for the government to reduce supports for those social enterprises that can raise funds through social stock exchanges. On the other hand, social enterprises which are not corporations legally can not use social stock exchanges. Hence, it can raise the efficiency if the government concentrates more on these social enterprises, which are not legal corporations, in terms of financial aids.

Effects of Long-Term Cryopreservation on Fat Grafts: An Experimental Study

이희종,김은기 대한미용성형외과학회 2014 Archives of Aesthetic Plastic Surgery Vol.20 No.2

Background Although microfat grafting is now used to augment soft tissue, resorption of some amount of fat is inevitable. There are no consistent guidelines for the duration of fat storage. This study evaluated absolute fat mass and pathological changes according to storage duration. Methods Nude mice were injected with fresh fat or fat that had been stored for 3 weeks, 5 months, 9 months, 15 months, or 22 months. After 15 weeks, fat graft weight and pathology (viable cells, structural integrity, microvessel formation, cystic degeneration, fibrosis, and cellular infiltration) were assessed. Results After 15 weeks, the average weight of the remaining fat was 486 mg in the control group and 298, 160, 180, 106, 88, and 80 mg in the 3-week and 5-, 9-, 15-, 22-, and 36-month storage groups, respectively. The average weight of fat tissue significantly decreased to less than 20% in the 5-month group. Also, there was a significant decrease in structural integrity and an increase in cystic degeneration in the 5-month group. Tissue vascularization tended to decrease according to the duration of cryopreservation. Conclusions The mean weight of the fat grafts preserved in a general freezer was reduced by 61.3% compared with that of the fresh fat group, which was not statistically significant. The mean fat graft weight was, however, significantly reduced following storage in a general freezer for longer than 5 months. In addition, there were decreases in viable adipocytes and increases in fibrocystic degeneration and inflammatory changes when long-term preserved fat was grafted.