분위기 조건에 따른 바이오디젤의 NOx 생성 특성 및 상세화학반응 경로 연구

정준우(Jun Woo Jung),임영찬(Young Chan Lim),서현규(Hyun Kyu Suh) 한국연소학회 2018 한국연소학회지 Vol.23 No.2

This paper was performed to investigate the effect of various ambient conditions on the biodiesel NOx formation characteristics. To achieve this, a closed homogeneous batch reactor model of CHEMKIN-PRO was used for the biodiesel combustion analysis and, surrogate fuels for the biodiesel combustion was consisted of n-heptane, methyl decanoate and methyl-9-decenoate. As a result of analysis, NOx production increases with increase of ambient temperature and pressure, and NOx production was the highest at Φ=0.7 of equivalence ratio condition. However, after the Φ=0.7 of equivalence ratio condition, it was confirmed that the decrease in NOX formation was caused by the lack of oxygen as the equivalence ratio was increased. In the biodiesel combustion, the main chemical reactions of NOx production is dominated by the thermal mechanism, and other NOx production is generated by the reaction mechanisms including N₂O mechanism and HO₂ radical.

화학반응 메커니즘 축소화 연구를 통한 바이오디젤의 연소 해석

정준우(Jun Woo Jung),임영찬(Young Chan Lim),서현규(Hyun Kyu Suh) 대한기계학회 2018 대한기계학회 춘추학술대회 Vol.2018 No.12

색 상관 관계 기반의 색조 검출 및 핵밀도 추정을 이용한 색 항상성 알고리즘

정준우(Jun-Woo Jung),김경환(Gyeonghwan Kim) 한국멀티미디어학회 2010 멀티미디어학회논문지 Vol.13 No.4

DRGEP 방법에서의 표적 화학종 변화가 메커니즘 축소에 미치는 영향

정준우(Jun Woo Jung),임영찬(Young Chan Lim),서현규(Hyun Kyu Suh) 한국연소학회 2019 한국연소학회지 Vol.24 No.3

This study investigated the effect of target species changing on the mechanism reduction in DRGEP(Directed Relation Graph Error Propagation) method. To achieve this goal, the automatic mechanism reduction scheme of reaction workbench which includes DRGEP method was introduced and the 0-D combustion analysis of CHEMKIN-PRO was executed to confirm the error rate of ignition delay between the detailed mechanism and reduced mechanisms. To consider various target species, the skeletal mechanism for biodiesel and n-heptane mechanism were merged and the various environments were considered to decide the environment of the mechanism reduction by changing the relative and absolute tolerance associated with the mechanism reduction. As a result, it was confirmed that the target species has a great influence on the reduction of the mechanism, and it was appropriate to consider chemical species, as the target species, associated with exhaust emissions.

복막 투석 환자에서 시행한 탈장 수술의 결과

정준우(Jun Woo Jung),유승범(Seungbum Ryoo),최은경(Eun Kyung Choe),박규주(Kyu Joo Park) 대한외과학회 2009 Annals of Surgical Treatment and Research(ASRT) Vol.77 No.5

Purpose: The incidence of hernia is estimated to be 3~5% in the general population. In patients on continuous ambulatory peritoneal dialysis (CAPD), the incidence of hernia is 6~25% and immediate surgical treatment is critical to maintain CAPD. This study was performed to identify clinical characteristics of hernias in CAPD patients and evaluate the surgical results. Methods: We retrospectively analyzed 13 prospectively registered patients (male : female=12:1) on CAPD treated with hernia between March 1998 and June 2008 at the Seoul National University Hospital by one surgeon. Perioperatively, patients underwent intermittent hemodialysis via internal jugular catheter indwelled just before the operation. Peritoneal dialysis was resumed between 2 weeks and 2 months after operation. Results: Mean age was 46.6 years (range: 19~71 years). Fifteen hernias developed in 13 patients, of which, 10 (67%) were inguinal and 5 (33%), umbilical. Mean duration from CAPD start to onset of hernia was 31.4 months (range: 0~129 months). All inguinal hernia patients received standard McVay operation, 3 patients with umbilical hernia were repaired with primary herniorrhaphy and 1 patient with large fascial defect needed mesh implant. During mean follow-up periods of 31 months, recurrence was detected in 1 patient in umbilical hernia group. The only complication related to operation was wound hematoma in one patient. Two patients were converted to hemodialysis after operation because of low compliance to peritoneal dialysis in one patient and suspected catheter-related infection in the other. Conclusion: Our results indicate that hernia repair can be safely performed with acceptable outcomes in patients on CAPD.

IoT 기반 냉동컨테이너 실시간 관리 시스템

문영식,정준우,최성필,김태훈,이병하,김재중,최형림,Moon, Young-Sik,Jung, Jun-Woo,Choi, Sung-Pill,Kim, Tae-Hoon,Lee, Byung-Ha,Kim, Jae-Joong,Choi, Hyung-Lim 한국정보통신학회 2015 한국정보통신학회논문지 Vol.19 No.9

사용이 증가하고 있는 냉동컨테이너에 적재된 화물의 손실을 방지하기 위해서는 냉동컨테이너의 실시간 상태 모니터링 및 원격 관리가 필요하지만 현재 냉동컨테이너의 대표적인 모니터링 방식인 PCT 방식은 모니터링만 가능할 뿐 냉동컨테이너 설정온도 관리 등 원격 관리 및 육상운송 중 실시간 모니터링이 불가능하다. 본 논문에서는 이러한 한계를 극복하기 위한 IoT 기반 냉동컨테이너 실시간 관리 시스템을 구현하였다. 이 시스템은 각 냉동컨테이너에 부착되어 냉동컨테이너 데이터 포트를 통해 RS-232 통신을 이용하여 냉동컨테이너의 실시간 데이터를 수집하고 이를 WCDMA/GSM 통신을 이용하여 데이터 수집 미들웨어로 전송한다. 미들웨어는 수신한 데이터를 데이터베이스에 저장하고 웹 및 모바일 프로그램을 통해 각 물류주체들에게 실시간으로 정보를 제공한다. 이때 웹 프로그램을 통해 사용자는 원격지에서 냉동컨테이너의 실시간 설정온도 변경이 가능하다. 끝으로 딸기화물을 실은 냉동컨테이너에 적용하여 운송과정을 실시간으로 모니터링하는 테스트를 통해 구현한 시스템의 기능을 검증하였다. To prevent damage to the cargo, monitoring and remote management for reefer containers is necessary. The currently used remote monitoring service is the Power Cable Transmission(PCT) system, which is recommended by the International Maritime Organization(IMO). However, this system is not widely used because it requires a separate PCT infrastructure and is susceptible to data loss problems. To solve this problem, this study introduces the "IoT-based reefer container management system", The proposed system which is attached to reefer container collects and transmits data on the temperature, status and location of reefer container to middleware using RS-232 communication and WCDMA/GSM communication. Middleware is store the data received in the database and provide information to user in real time through the web and mobile program. At this time, users able to change setting temperature in real time from a distant place through the web program. This study tested by transit about shipment of strawberries to monitor and analyze and check the system's overall effectiveness.

이동셀룰러망에서 무선 인지 기반 비협력 동적 주파수 자원 할당 기법

유현,정준우,이종관,임재성,Yu, Hyun,Jung, Jun-Woo,Lee, Jong-Kwan,Lim, Jae-Sung 한국군사과학기술학회 2011 한국군사과학기술학회지 Vol.14 No.5

In this paper, we propose uncoordinated dynamic frequency(channel) allocation schemes based on cognitive radio in mobile cellular networks(MCNs). Under the assumptions that mobile base stations are equipped with cognitive radio(CR) function and they construct uncoordinated network, the proposed scheme enables the MCNs by suppression of successive channel switching and management of channel allocation in a dynamic and distributed manner. The proposed scheme is composed of two phase processes. In the first phase, highly orthogonal sequences are generated and assigned to mobile base stations. In the second phase, each mobile base station is allocated a channel according to the pre-assigned orthogonal sequences. Simulation results show that the number of successive spectrum switching is reduced significantly compared with the random switching scheme.

IoT 기반 실시간 냉장컨테이너 상태 모니터링 시스템

문영식,정준우,최성필,김태훈,이병하,김재중,최형림,Moon, Young-Sik,Jung, Jun-Woo,Choi, Sung-Pill,Kim, Tae-Hoon,Lee, Byung-Ha,Kim, Jae-Joong,Choi, Hyung-Lim 한국정보통신학회 2015 한국정보통신학회논문지 Vol.19 No.3

In this paper, we propose the reefer container monitoring system that not only monitors internal temperature, humidity of reefer container but also tracks the real-time location using GPS. It consists of a tag of information of situation using 433MHz RF transmitter(communication), GPS to track the real-time location and a device using WCDMA/GSM communication to transmit information to the server. We tested by applying the proposed system in reefer containers with yellow melons, melons transported from Korea to Singapore to track the location and check the temperature and the humidity. The result of this test is that there is a temperature difference around 1.7 degree depending on the position of inside of container and maintains the humidity stably about 97%. If we apply this proposed system to agricultural marketing, it is possible to get the time that fruits start to decay and minimize the loss of fruits by decaying during shipping. 본 논문에서는 냉장컨테이너 내부에 부착되어 냉장컨테이너 내부 온도와 습도를 감지하고, 이를 433MHz RF통신을 이용하여 정보를 전송하는 냉장컨테이너 내부 상태 정보 수집 태그와 냉장컨테이너 외부에 부착되어 냉장컨테이너의 동작 상태 수집 및 GPS를 통해 실시간 위치를 확인하고 WCDMA/GSM 통신을 이용하여 정보를 서버로 전달하는 냉장컨테이너 상태 모니터링 장치로 구성된 IoT 기반 실시간 냉장컨테이너 상태 모니터링 시스템을 소개한다. 또한 소개한 모니터링 시스템을 국내에서 출발하여 싱가포르까지 운송되는 참외, 멜론을 가득 실은 냉장컨테이너에 적용하여 운송 중 실제 냉장컨테이너 내부의 온도, 습도가 어떻게 유지되고 있는지를 확인하였다. 확인 결과 냉장컨테이너 설정온도와 달리 냉장컨테이너 내부 위치에 따라 약 $1.7^{\circ}C$ 내외의 온도 차이가 발생하였으며, 습도는 위치에 관계없이 약 97%로 유지되는 것을 확인하였다. 본 논문에서 소개하는 모니터링 시스템을 신선농산물 유통에 적용하면 농산물 운송 중 신선 농산물의 부패가 언제 발생하는지 확인이 가능하여 이를 토대로 부패가 진행되는 환경을 개선한다면 손실률을 최소화 하면서 냉장컨테이너를 이용한 신선 농산물의 운송이 가능해 질 것으로 기대된다.

아킬레스건 파열의 수술적 치료 결과 비교

김정한(Jung-Han Kim),곽희철(Heui-Chul Gwak),이창락(Chang-Rack Lee),김전교(Jeon-Gyo Kim),정준우(Jun-Woo Jeong) 대한정형외과학회 2017 대한정형외과학회지 Vol.52 No.3

목적: 아킬레스건 파열에 대한 수술적 치료 중 최소 절개 경피적 봉합술과 관혈적 봉합술의 임상적 결과를 비교 분석하고자 하였다. 대상 및 방법: 2006년 1월에서 2014년 6월까지 최소 절개 경피적 봉합술을 시행 받은 25명의 환자들(1군)과 관혈적 봉합술을 시행 받은 30명의 환자들(2군)의 임상적 결과를 후향적으로 분석하였다. 술 후 임상적 평가는 Arner-Lindholm scale, American Orthopedic Foot and Ankle Society (AOFAS) hind foot score, 환자의 만족도 및 흉터에 대한 미용적인 만족도로 하였다. 결과: 두 군 간의 AOFAS ankle-hindfoot score, 중간 장딴지 둘레 차이, 환자의 만족도 및 반흔에 대한 만족도 면에서는 통계적으로 유의한 차이를 보였으며 1군이 2군보다 우수한 결과를 나타냈다. 그 외의 임상적 결과에서는 통계적으로 유의한 차이를 보이지 않았다. 1군에서 비복신경손상이 2예 있었으며, 2군에서는 심부감염, 재파열, 심부정맥 혈전증의 3예의 합병증이 있었다. 결론: 아킬레스건 파열에 대한 수술적 치료에 있어 최소 절개 경피적 봉합술이 효과적인 치료법 중의 하나로 고려될 수 있을 것이다. Purpose: To compare and analyse the clinical outcomes between minimal-incision percutaneous repair and open repair among the surgical treatments for Achilles tendon ruptures. Materials and Methods: We retrospectively analyzed and compared the outcomes between 25 patients with minimal incision percutaneous repair (group 1) and 30 patients with open repair (group 2), from January 2006 to June 2014. The postoperative clinical evaluations were done by Arner-Lindholm scale, American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, overall patient"s satisfaction, and cosmetic satisfaction of scar. Results: There were statistically significant differences between the two groups with respect to AOFAS hind foot score, mid-calf circumference differences, overall patient’s satisfaction, and satisfaction of scar; the group 1 showed better achievement. There was no statistical difference between two groups in regards to other clinical outcomes. In group 1, there were 2 cases of sural nerve hypoesthesia, which fully recovered spontaneously at about 6 months after the surgery. In group 2, there were 3 cases of deep vein thrombosis, re-rupture, and deep infection. Conclusion: We recommend minimal incision percutaneous repair as one of the effective surgical treatment options for Achilles tendon ruptures.

실시간 냉동컨테이너 관리 시스템 개발

최성필,정준우,문영식,김태훈,이병하,김재중,최형림,이은규,Choi, Sung-Pill,Jung, Jun-Woo,Moon, Young-Sik,Kim, Tae-Hoon,Lee, Byung-Ha,Kim, Jae-Joong,Choi, Hyung-Lim,Lee, Eun-Kyu 한국정보통신학회 2015 한국정보통신학회논문지 Vol.19 No.12

컨테이너선의 대형화에도 불구하고 냉동컨테이너의 관리는 대부분 인력에 의존하고 있다. 악천후 및 야간의 경우 냉동컨테이너에 대한 정확한 모니터링이 이루어지지 않으며, 작업을 하더라도 사고 발생 확률이 높은 것이 사실이다. 이러한 위험을 줄이기 위해 국제해사기구에서 전력선모뎀(PLC Modem)을 이용한 시스템을 권장하고 있으나 대부분의 선박에서 해당 시스템을 사용하지 못하고 있다. 이로 인해 화주 및 기타 화물과 관계된 모든 주체들이 해상운송 과정에서의 정보 파악이 되지 않아 운송 중인 화물에 대한 신뢰성이 저하되고 있다. 이러한 비효율적인 업무를 해결하고 동시에 전 세계로 널리 활용되고 있는 모든 냉동컨테이너의 효율적 관리를 위한 본 논문에서는 IoT기반 실시간 냉동컨테이너 제어 및 모니터링 시스템을 제시하고자 한다. In spite of a recent trend of container ships becoming larger in size, the current circumstance is that managing reefer containers marine transportation is being mostly dependent upon manpower. Particularly, in the case of bad weather or nighttime, reefer containers are not being monitored due to lack of safety device. For the purpose of reducing such risk, IMO is recommending a system using PLC but the system is not being used. In addition, they are still relying on manpower for control and reliability of freight in transit is decreasing due to lack of information during marine transportation for every subject related to freight as well as shipper. Accordingly, the purpose of this paper is to propose a real-time reefer container management system to effectively control all reefer containers widely being used across the world.