조기 뇌동맥류 수술전에 항섬유소융해제 치료의 이점

김종문,강성돈,Kim, Jong Moon,Kang, Sung Don 대한신경외과학회 2001 Journal of Korean neurosurgical society Vol.30 No.6

Objective : Antifibrinolytic treatment after aneurysmal subarachnoid hemorrhage has been shown to have no significant effect on outcome since a reduction in the rate of rebleeding was offset by an increase in the incidence of hydrocephalus and ischemic events. As the results of early aneurysm surgery and a change of strategy in the intensive medical treatment, outcome in patients with cerebral ischemia has been improved. On the other hand, rebleeding still remains as a major cause of death. A short course of tranexamic acid(TA) was tried to study its efficacy and safety in reducing the incidence of rebleeding before aneurysm surgery. Methods : A total of 507 patients with ruptured cerebral aneurysm operated within 3 days after the attack from 1990 to 1999 were included in this study. Group A consisted of 302 consecutive patients treated from 1990 through 1995 served as control. Two hundred-five patients in group B were treated with TA from 1996 through 1999. Both groups were evaluated for comparability of demographic and clinical variables including age, Hunt-Hess grade, Fisher grade, aneurysm location, hypertension, day of surgery, and initial hydrocephalus. The relationships of TA with rebleeding, ischemia, and chronic hydrocephalus were also studied. Results : There was no significant difference in patient demographics and clinical characteristics between group A and group B. Sixteen patients(5.3%) suffered a recurrent hemorrhage in group A and three(1.5%) in group B(p<0.05). Chronic hydrocephalus requiring a shunt was found in a significantly greater proportion in group B than in group A(p<0.05). The incidence of cerebral ischemia was not elevated in group B compared with group A. Conclusion : Considering the fact that the reduction of fatal rebleeding outweighed the increased incidence of hydrocephalus, the authors believe that a short course of TA is beneficial in diminishing the risk of rebleeding prior to early surgical intervention.

지주막하출혈에 의한 지연성 허혈신경장애의 진단에 있어서 경두개도플러 검사의 신뢰도

김종문,강성돈,Kim, Jong Moon,Kang, Sung Don 대한신경외과학회 2000 Journal of Korean neurosurgical society Vol.29 No.7

Objective : The reliability of transcranial doppler sonography(TCD) for predicting delayed ischemic neurologic deficit( DIND) was investigated in patients with aneurysmal subarachnoid hemorrhage(SAH). Methods : The velocity of blood flow through the middle cerebral artery was measured by TCD in 70 patients treated surgically within 72 hours due to ruptured cerebral aneurysm. A correlation between measured maximal mean blood flow velocities and clinical factors including age, hypertension, Hunt-Hess grade, Fisher grade, DIND, and outcome was made. Results : An age-dependent reduction of the measured maximal mean velocities was found(r=-0.4043, p<0.001). Flow velocities in hypertensive patients were significantly lower than in the normotensive individuals(two-tailed T test, p<0.05). There was no significant difference between the flow velocities and evaluated other clinical factors. When the flow velocities of 14 patients who developed DIND were compared with those of patients without deficits, no significant difference was seen. A significant increase in flow velocities in the days before the onset of DIND was found only in 4 of 14 cases. High flow velocities did not necessarily mean impending neurological deficits : 6 of 70 patients tolerated flow velocities over 160cm/s. Conclusion : We suggest that TCD readings have limited utility for predicting DIND following SAH, especially in older or hypertensive patients. More direct measurements of blood flow are necessary to adequately predict which patients are at high risk of DIND.

습식법에 의한 Hydroxyapatite 분말제조와 그 분체특성

김종문,김겸,이서우,Kim, Jong-Moon,Kim, Kyum,Lee, Seo-Woo 한국세라믹학회 1991 한국세라믹학회지 Vol.28 No.1

The hydroxyapatite powders were prepared by the reaction of Ca(CH3COO)2$.$H2O and H3PO4 in aqueous solution. Effect of Ca/P mole ration and pH value on the powder characteristics were investigated. For phosphoric acid was dissociated to PO43- ion above pH 10, the preparation condition of hydroxyapatite by H3PO4 solution had this value. Dried powders were agglomerated each other. The mean agglomerate particle diameter was minimum when the condition was pH 11, Ca/P=1.75 and its specific surface area was 97㎡/g. All powders had poor crystallinity and small CO2. It prevented CaCO3 from using aspirator in preparation and maturing time. In most cases, hydroxyapatite was decomposed into ${\beta}$-TCP at more than 800$^{\circ}C$, into ${\alpha}$-TCP at 1200$^{\circ}C$. However non-decomposed hydroxyapatite was remained in Ca/P=1.85.

준밀폐형 2상자연순환 회로 내에서의 유동 진동에 관한 실험적 연구

김종문,이상용,Kim, Jong Moon,Lee, Sang Yong 대한기계학회 1998 大韓機械學會論文集B Vol.22 No.12

In the present experimental study, the flow behavior in a semi-closed two-phase natural circulation loop was examined. Water was used as the working fluid. Heat flux, heater-inlet subcooling, and flow restrictions at the heater-inlet and at the expansion-tank-line were taken as the controlling parameters Six circulation modes were identified by changing heat flux and inlet subcooling conditions ; single-phase continuous circulation, periodic circulation (A), two-phase continuous circulation, and periodic circulations (B), (C), and (D). Among these, the single-phase and two-phase continuous-circulation modes exhibit no significant oscillations and are considered to be stable. Periodic circulation (A) is characterized by the large amplitude two-phase f10w oscillations with the temporal single-phase circulation between them, while periodic circulation (B) featured by the flow oscillations with continuous boiling inside the heater section. Periodic circulation (C) appears to be the manometric oscillation with continuous boiling. Periodic circulation (D) has the longer period than periodic circulation (B) and a substantial amount of liquid flow back and forth through the expansion-tank-line periodically ; this mode is considered the pressure drop oscillation. Parametric study shows that the increases of the inlet- and expansion-tank-line- restrictions and the decrease of inlet subcooling broaden the range of the stable two-phase(continuous circulation) mode.

다중 자기부상 시스템의 분산형 $H_{\infty}$ 제어

김종문,이상혁,최영규,Kim Jong-Moon,Lee Sang-Hyuk,Choi Young-Kiu 대한전기학회 2005 전기학회논문지 D Vol.54 No.12

In this paper, an application of a decentralized $H_{\infty}$ controller(DHC) to multiple controlled-permanent magnet(CMAG) magnetic levitation(Maglev) systems is presented. The designed DHC using two Riccati equations iteratively has simpler structure and needs less computational loads than conventional centralized $H_{\infty}$ controller. A target plant is a hybrid-type CMAG system with permanent magnet and coil, and its mathematical model is firstly derived to design the DHC. To implement the designed algorithm, a real Maglev vehicle system including digital controller, chopper, sensor, etc., is manufactured. To compare the performances of the DHC method with an observer-based state feedback control(OSFC), the input tracking and disturbance rejection characteristics are experimentally tested. As performance indices(PI), integral of squared error(ISE), integral of absolute error(IAE), integral of time multiplied by absolute error(ITAE) and integral of time multiplied by squared error(ITSE) are used. From the experimental results, it can be seen that the input tracking and disturbance rejection performances of the DHC are better than those of the conventional controller.

폐벌목(廢伐木)에서 활성탄(活性炭) 개발(開發)을 위한 목탄(木炭) 제조(製造)의 최적화(最適化) 방안(方案)에 관(關)한 연구(硏究)

김종문,정찬교,민병훈,Kim, Jong-Moon,Chung, Chan-Kyo,Min, Byong-Hoon 한국자원리싸이클링학회 2008 資源 리싸이클링 Vol.17 No.5

Using a pinus koraiensis and pinus rigida which are normally being discarded in South Korea, the optimal condition of producing charcoals has been studied to develop activated carbons which can be recycled as a higher value-added product. A study on manufacture of activated carbons from a discarded timber consists of two processes, the production process of charcoals from a discarded timber by low temperature pyrolysis process and the production process of activated carbons from the charcoals by chemical activation reaction. This study deals with the production process of charcoals from a discarded timber by low temperature pyrolysis process. As a results of experiment, it was investigated that charcoals produced through drying at $150^{\circ}C$ for 6hr and pyrolysis process at $500^{\circ}C$ for 1hr had the highest values in physical properties such as iodine number and BET surface area. Furthermore, through observing SEM images, the maximum development of porosity had been founded in this condition. It was confirmed that values of physical properties on using a pinus koraiensis are superior to the ones when using a pinus rigida. When charcoals were produced from a pinus koraiensis in this condition, BET surface area was approx. $640m^2/g$. 국내에서 대표적으로 버려지는 폐벌목인 잣나무와 리기다소나무를 이용하여 고부가가치 제품으로 활용할 수 있는 활성탄 개발을 위해 목탄 제조의 최적조건을 측정하였다. 폐벌목 활성탄 제조에 관한 연구는 저온열분해 공정에 의한 폐벌목의 목탄 제조공정과 화학적 활성화반응을 이용한 목탄의 활성탄 제조공정으로 나누어지며 본 논문은 저온열분해에 의한 폐벌목의 목탄 제조공정을 다루고 있다. 실험결과, 목탄 제조공정의 경우 $150^{\circ}C$에서 6시간 건조 후 $500^{\circ}C$에서 60분 동안 열분해 공정을 거쳐 생성된 목탄이 요오드 흡착력과 비표면적(BET)등의 물성이 가장 우수하였으며 SEM사진을 관찰한 결과 이 조건에서 세공이 발달함을 알 수 있었다. 일반적으로 잣나무를 이용하여 제조된 목탄의 물성치가 리기다소나무를 이용한 목탄보다 우수함을 알 수 있었다. 본 연구의 최적 실험조건에서 잣나무를 이용한 목탄의 경우 BET값이 약 $640m^2/g$에 이르렀다.

$H_{infty}$ 제어기의 자기부상 시스템에의 적용

김종문,김석주,박민국,최영규,Kim, Jong-Moon,Kim, Seog-Joo,Park, Min-Kook,Choi, Young-Kiu 대한전기학회 2002 전기학회논문지 D Vol.51 No.11

In this paper, a suspension control of a magnetic levitation(MagLev) system with flexible rail is designed and presented. The numerical modelling for the electromagnetic system to be controlled as a target plant is carried out. And dome kinds of the hardware system including CPU board, AD board, DA board, sensors, and switching power amplifier are described. Using the derived model, the stabilizing controllers, such as PID and $H_{\infty}$ controller, for the MagLev system are designed using the MATLAB toolbox. The designed controllers are validated by some experimental results as well as numerical simulations. So it is shown that $H_{\infty}$ controller can give the better performance for the plant with flexible modes than PID controller.

폐벌목(廢伐木)을 이용(利用)한 활성탄(活性炭) 개발(開發)에 관(關)한 연구(硏究)

김종문,정찬교,민병훈,Kim, Jong-Moon,Chung, Chan-Kyo,Min, Byong-Hoon 한국자원리싸이클링학회 2008 資源 리싸이클링 Vol.17 No.6

국내에서 대표적으로 버려지는 폐벌목인 잣나무와 리기다소나무를 이용하여 고부가가치 제품으로 활용할 수 있는 활성탄 개발을 위해 활성탄 제조의 최적조건을 측정하였다. 폐벌목 활성탄 제조에 관한 연구는 저온열분해 공정에 의한 폐벌목의 목탄 제조공정과 화학적 활성화 반응을 이용한 목탄의 활성탄 제조공정으로 나누어지며 본 논문은 화학적 활성화 반응을 이용한 목탄의 활성탄 제조공정을 다루고 있다. 일반적으로 활성화제는 알칼리 약품을 이용하고 있으며 본 연구에서는 탄소와 활성화 반응이 잘 이루어지는 KOH와 NaOH를 사용하였다. 실험결과, KOH로 제조된 활성탄이 NaOH로 제조된 활성탄 보다 요오드 흡착력과 비표면적(BET) 등 물성이 우수하였으며 이는 세정공정 후 활성탄의 잔류물이 KOH는 검출되지 않았으나 NaOH는 $3{\sim}4%$의 잔류물이 있는 것으로 보아 목탄과 KOH의 반응이 더 활발함을 알 수 있었다. 일반적으로 잣나무를 이용하여 제조된 활성탄의 물성치가 리기다소나무를 이용한 활성탄 보다 우수함을 알 수 있었다. 목탄과 활성화제의 최적 침적비율은 400 wt.%임을 알 수 있었다 세정방법은 5M 염산용액으로 세척하여 중화시킨 후 증류수로 세정하는 방법이 활성탄의 물성을 높일 수 있었다. 본 연구의 최적 실험조건에서 잣나무를 이용하여 제조된 활성탄의 경우 BET값이 약 $2400\;m^2/g$에 이르렀다. Using a Pinus koraiensis and Pinus rigida which are normally being discarded in South Korea, optimal conditions of producing activated carbons have been studied to recycle as a higher value-added product. This study consists of two processes, the production process of charcoals from waste timbers by low temperature pyrolysis and the production process of activated carbons from the charcoals by chemical activation reaction. This paper deals with the production process of activated carbons from the charcoals by chemical activation reaction. As an alkali has been generally used as an activating agent, KOH and NaOH which react well with a carbon were used in this study. As a result of the experiments, it is confirmed that activated carbons made with KOH treatment had superior values in physicochemical properties to NaOH, showing that there was no remain of KOH at the surface of the charcoals while there was $3{\sim}4%$ of NaOH remaining after the experiments. Thus, it is concluded that KOH reacted more actively with a charcoal than NaOH. Moreover, it was also found that values in physicochemical properties when using a Pinus koraiensis are superior to the ones when using a Pinus rigida. The optimal mixing ratio of an activating agent to a charcoal was 400 wt.%. To improve the physicochemical properties, activated carbons were washed out by distilled water after neutralization with SM hydrochloric acid solution. When activated carbons were produced from a Pinus koraiensis in this optimal conditions, value of BET surface area was found to be approx. $2400\;m^2/g$.

수분함량에 따른 의치접착제의 확장성 관찰

김종문,최성민,Kim, Jong-Moon,Choi, Sung-Min 대한치과기공학회 2015 대한치과기공학회지 Vol.37 No.1

Purpose: In this study, Spreadability of denture adhesive in accordance with the saturation level of saliva, respectively, by using the resin plate and the glass was measured thickness and Spreadability. Methods: Examine the spreadability of denture adhesive in accordance with the saturation level of saliva, respectively, by using the resin plate and the glass was measured thickness and Spreadability. Also, by measuring the adhesive strength according to the amount of saliva, and the edentulous patients using denture adhesive and dry mouth patients attempt to provide clinical information of the denture adhesive. Therefore, by using the relatively low shrinkage cold curing resin, after fabricating specimen of plate form, for 7 days, it was immersed in water. Results: For the control group only denture adhesive, an artificial saliva for the experimental group were injected in $0.1m{\ell}$, $0.2m{\ell}$ and $0.3m{\ell}$ of the denture adhesive on the surface, experimental results of the investigation of the 10 times the tensile bond strength of the specimens in each group was obtained the following results. Conclusion: As the time to pressure increase in the same amount of saliva was found that the amount coming out of the denture adhesive, as the amount of saliva in the same pressure increase coming out of many denture adhesives. And the greater the pressure came out a lot of denture adhesives. Spreadability in measuring saliva contact with $0.1m{\ell}$ and $2m{\ell}$ and $3m{\ell}$ group pressured the diameter of the circular was the denture adhesive is small when compared to the group without adding the pressure of 2kg and 3kg put the saliva. The size of the circle is the same amount of saliva denture adhesive spread more pressure showed a greater increase.

Estimation of Frequency Offset in TDMA-Based Satellite Systems

김종문,이용환,Kim Jong-Moon,Lee Yong-Hwan The Korean Institute of Communications and Informa 2006 韓國通信學會論文誌 Vol.31 No.4c

TDMA 시스템에서 신호를 수신하기 위해서는 정확한 주파수 및 시간 동기가 필요하다. 본 논문에서는 QPSK 신호를 전송하는 TDMA 방식의 위성통신 시스템에서 훈련 신호 없이 주파수 편이를 추정하는 방법을 제안한다. 제안된 방법은 수신 신호의 두 부분에서 정확도가 높게 위상을 추정하고, 이 위상 차이로부터 주파수 편이를 추정함으로써 기존의 주파수 편이 추정 방법과 비슷한 성능을 보이면서 적은 연산량이 요구된다. 제안된 방법을 GSM을 기반으로 확장된 GMR 위성통신 시스템에 적용하고 시뮬레이션을 통해 성능을 검증한다. It is required for correct signal detection to accurately maintain the synchronization of frequency and timing in a TDMA system. In this paper, we consider nondecision-aided estimation of frequency offset for the transmission of QPSK signal in a TDMA-based satellite system. The proposed scheme estimates the phases of two parts in the burst and then estimates the frequency offset based on the difference between the two estimated phases. Thus, it can provides performance comparable to that of conventional schemes, while significantly reducing the implementation complexity, The performance of the proposed scheme is analyzed and verified by computer simulation, when applied to a GSM based geostationary earth orbit mobile radio(GMR) system.