ATM 네트워크에서 통계적 다중화 이득에 의한 버스트 트래픽의 제어방식

黃在政,朴世煥 군산대학교 1992 群山水産專門大學 硏究報告 Vol.26 No.1

ATM(Asynchronous Transfer Mode) network for the realization of B- ISDN(Broadband - Integrated Services Digital Network) has the burst traffic characteristics, temporally varying transmission speed. General research works have been performed for the higher transmission performance using the burst traffic control methods. In this paper we simulated network availability under the ATM environment which has multiplexed burst traffic properties and proposed realizing methods by statistical multiplexing gains for high quality ATM traffic.

조사광이 통과하는 치질의 두께와 광조사시간에 따른 광중합형 복합레진의 중합률에 관한 연구

황기환,장인호,이세준,이광원 大韓齒科保存學會 2002 Restorative Dentistry & Endodontics Vol.27 No.1

Physical properties of composite resins such as strength, resistance to wear, discoloration, etc depend on the degree of conversion of the resin components. The purpose of this study was to evaluate the degree of conversion of the composite resins according to the thickness of tooth structure penetrated by light and applied light curing time. The coronal portions of extracted human teeth( one anterior tooth, three posterior tooth) was embedded by pink denture material. the mounted teeth were cut into three illumination sections (1mm thickness enamel section, 1mm thickness dentin section, 2mm thickness dentin section) and one backing section with cutting wheel. Thin resin films were made by using 6kg pressure between slide glass during 5 minutes. Thin resin film was light cured on coupled illumination section during 40sec, 80sec and 120sec. each illumination section was coupled as follows: no tooth structure(X), ename section(E), enamel section + 1mm dentin section(ED1), enamel section + 2mm dentin section(ED2), enamel section + 1mm dentin section + 2mm dentin section(EDD). To simulate the clinical situation more closely, thin resin film was cured against a backing section of tooth structure. The degree of conversion of carbon double bonds to single bonds in the resin films were examined by means of Fourier Transform Infrared Spectrometer. The results were obtained as follows; 1. As curing time was increased, conversion rate was increased and as tooth thickness which was penetrated by curing light was increased, conversion rate was decreased. 2. At all tooth thickness groups, conversion rate between 80sec and 120sec was not significantly increased(P>0.05). 3. At 40sec group and 80sec, conversion rate between no tooth structure(X) group and 1mm enamel section(E) group was not significantly decreased(P>0.05). 4. At 80sec group and 120sec, conversion rate between 1mm enamel section(E) group and 1mm enamel section + 1mm dentin section(ED1) group was not significantly decreased(P>0.05).

사춘기전 Ⅰ,Ⅱ급 부정교합 아동의 기도 면적, 혀의 위치와 안면 형태에 관한 연구

황용인,이규홍,이기준,김상철,조형준,천세환,박양호 대한치과교정학회 2008 대한치과교정학회지 Vol.38 No.2

본 연구는 사춘기 성장 이전의 I, II급 부정교합을 갖는 아동 환자들의 측모 두부 규격 방사선사진을 이용하여 두개 안면 형태를 조사하고 이들과 혀의 위치 및 면적, 기도의 면적과의 관계를 조사하여 비인두 기도 및 혀의 형태가 악골 및 부정 교합의 형태에 미치는 영향을 알아보았다. 9 - 11세의 교정환자 76명을 대상으로 측모 두부 규격 방사선사진상 ANB difference를 기준으로 대조군(I급 부정교합군: 0 ≤ ANB difference < 4.0)과 실험군(II급 부정교합군: ANB difference ≥ 4.0)으로 분류하였다. 혀 면적, 혀와 구개 사이의 면적, 비인두 기도 면적과 두개안면형태 항목을 측정하고 비교하여 다음과 같은 결과를 얻었다. 혀 면적, 혀와 구개 사이의 면적, 비인두 기도 면적은 II급 부정교합군과 I급 부정교합군 간에 유의한 차이를 보이지 않았다. Hyperdivergent안면 형태일수록 비인두 기도 면적이 좁았다. 안모의 전후방 수직 길이가 길수록 혀의 면적이 넓었고, 전안면 고경이 길수록 혀는 하방위치 하였다. 비인두기도 면적이 좁을수록 혀의 면적도 좁아졌다. 이상의 연구 결과 혀의 면적과 위치, 비인두 기도의 면적은 I급, II급 부정교합 간에 차이를 보이지 않으며 hyperdivergent 안면 형태 및 안모의 전후방 수직 길이와 관련이 있는 것으로 사료된다. Objective: This study examined the craniofacial morphology of young patients in their prepubertal stage showing class I, II malocclusion, by analyzing lateral cephalograms, and analyzed its relationship with tongue position, tongue space, and airway space in order to ascertain the effects of nasopharyngeal airway and tongue morphology on the form of the malocclusion. Methods: Seventy-six patients aging from 9 to 11 were divided into two groups depending on the ANB difference on the lateral cephalogram: Experimental grouP (CI II malocclusion group) showing 0 ≤ ANB difference < 4.0; Control group (CI I malocclusion group) showing 0 ≤ ANB difference < 4.0. The tongue space, space between palate and tongue, nasopharyngeal airway space and craniofacial morphology were compared between the two groups. Results: Tongue space, Palate-tongue space, nasopharyngeal airway space showed no significant differences between class I and class II malocclusion groups. Hyperdivergent faces were associated with smaller nasopharyngeal airway space. Longer anterior facial height and posterior facial height were associated with larger tongue space, and greater anterior facial height were associated with lower tongue position, Smaller nasopharyngeal airway space showed smaller tongue space. Conclusions: Tongue space and nasopharyngeal airway space showed no significant differences between class I malocclusion group and class II malocclusion group. Only anterior facial height and posterior facial height had an influence on tongue space and nasopharyngeal airway space.

The effect of combined Rehmannia glutinosa Libosch and Eleutherococcus senticosus Max(OPB) extracts on bone mineral density in ovariectomized rats.

Kim,Jung-Keun 대한구강생물학회 2007 International Journal of Oral Biology Vol.32 No.4

This study was conducted to investigate the preventingeffects of OPB (Rehmannia glutinosa Libosch and Eleuth-erococcus senticosus Max extracts) and combined OPB/Calcium therapy on bone loss in ovariectomized rats. SixtySprague Dawley rats of 12-week-old were divided into eightgroups: OVX (ovariectomized), OPBL (OPB 50mg/kg),OPBM (OPB100mg/kg), OPBH (OPB 200mg/kg), OPBL/CAL(OPBL+CAL), OPBM/CAL (OPBM+CAL), OPBH/CAL (OPBH+CAL) and CAL (Calcium citrate 88.33mg/kg+1α, 25-dihydroxy-vitamin D3 33.33IU/kg). Bone mineraldensity (BMD), bone mineral content (BMC), bone strengthindices and cortical thickness were analyzed by peripheralquantitative computerized tomography (pQCT). pQCTscanning showed that OVX induced a significant decreasein trabecular bone mineral density and bone mineralcontent in the proximal tibia (-36.4±2.4%, -21.8±12.7%).These decreases were significantly prevented by theadministration of OPBM and OPBM/CAL. Cortical BMDand BMC of tibia were slightly enhanced by OPB and OPB/CAL. However there was no significant difference betweenOVX and OPB, OPB/CAL treated group. Bone strengthindices and cortical thickness were not significantly different.Our results suggest that OPB and combined OPB/Calciumtherapy are effective in preventing the development of boneloss induced by ovariectomy in rats.

도장작업시 유해인자들의 노출수준과 작업환경관리실태

이세기,문덕환,이채관,황용식,선병관,손병철,김대환,이창희,김휘동,이채언 인제대학교 백병원 2002 仁濟醫學 Vol.23 No.5

Objectives: For the purpose of preparing the fundamental data and assessing the status of exposure level of chemical substances in painting process. Methods and Materials: The author determined the concentration of organic solvents, lead(Pb), Chromium(Cr), and Toluene-2, 4-diisocyanate(TDI) in air of painting process to 90 industries classified by 15 types of manufacturing industry during a period from Jan. 1st 2001 to Dec. 31st 2001. Results: The results were as follows: 1. The geometric mean level of each chemical substance was 0.1706 ppm for exposure index in organic solvents, 0.0019㎎/㎥ for Pb, 0.0024 ㎎/㎥ for Cr, and 0.0004ppm for TDI, respectively. 2. The exposure level of each chemical substances by type of painting was the highest in dipping and brush painting for organic solvent, in spray-painting for TDI, and in spray gun-painting for Pb and Cr, respectively. 3. The exposure level of each chemical substances by type of local ventilation equipment was higher in enclosed and booth type for organic solvents. Cr, and TDI, and in exterior type for Pb, respectively than those of other types. 4. The exposure level of each chemical substances by type of hazardous material arresting media was higher in using water for organic substances, in using bag filter for Pb, TDI, respectively than those of other types. Conclusion: According to above results, this study suggests that the exposure level by type of industry exceeded the exposure level in wooden furniture and metal furniture manufacturing industry for organic solvents and Pb, respectively.

3차 의료기관에 입원한 노숙환자에서 감염질환의 유병율

함세운,남기석,노혜진,홍경득,황래석,방지환,신형식 대한감염학회 2007 감염과 화학요법 Vol.39 No.4

목적 : 3차 의료기관에서 입원치료를 받았던 노숙자를 대상으로 감염성 질환의 유병율을 알아보고자 하였다. 재료 및 방법 : 2002년 1월부터 2004년 8월 사이에 국립의료원에서 입원 치료를 받았던 269명의 노숙자 환자들을 대상으로 의무기록을 조사하였다. 결과 : 연구 기간동안 입원치료를 받은 총 269명의 노숙자 환자 중 남자가 249명(92.9%), 여자가 19명(7.1%)이었다. 감염질환의 유병율은 B형 간염이 228명 중 15명(6.6%), C형 간염 113명 중 8명(7.1%), 결핵은 269명중 19명(7.1%), VDRL 양성인 경우는 234명 중 25명(10.7%), 항사람면역결핍바이러스항체 양성은 130명중 2명(1.5%)이었다. B형 간염표면항원에 대한 항체 형성자는 118명(51.7%), 항체 미형성자는 95명(41.7%)이었다. 결핵으로 진단된 19명 중 객담도말 및 배양검사와 조직검사로 확인된 경우가 14명, 균음성이나 임상적으로 의심되는 경우가 5명이었다. 간질환 및 관련된 합병증으로 입원한 환자 28명 중 B형 및 C형 간염바이러스에 관련된 경우는 5명(17.9%)에불과하였고 결핵은 19명중 13명(68.4%)이 폐결핵 및 림프절종대의 증상으로 입원치료를 받았다. 복합 감염의 경우는 총 9명이었는데 후천면역결핍증후군 환자였던 2명중 1명이 결핵에 이환되어 있으면서 VDRL 양성소견을 보였고 다른 1명이 HIV와 결핵의 동시감염이었다. 결론 : 노숙자 입원환자에서 결핵, C형 간염 및 매독의 유병율이 일반 인구에 비해 높았다. 노숙자환자를 담당하는 의료인력를 보호하고 환자의 감염질환 유무를 파악하기 위해 적절한 선별검사가 필요하며 감염질환의 확산을 방지하기 위한 정부의 적극적인 대책이 필요하다. Background : Despite the expected high prevalence of several infectious diseases among the homeless, a majority of them have not received screening test and early treatment. Materials and Methods : The subjects of this study were 269 homeless patients who had been hospitalized in the National Medical Center (Korea) between January 2002 and August 2004. Their medical histories and records were reviewed to analyze the prevalence and clinical characteristics of hepatitis B and C, syphilis, tuberculosis and HIV infection among them. Results : The entire 269 homeless patients being hospitalized during the period of this study consist of 249 male patients and 19 female patients. For the prevalence of infectious diseases, HBV was seen in 15 of 228 patients (6.6%); HCV in 8 of 113 patients (7.1%); VDRL positive in 25 of 234 patients (10.7 %); HIV antibody positive in 2 of 130 (1.5%); and tuberculosis in 19 of 269 (7.1%). The number of patients who had the antibody to hepatitis B was 118 (51.7%). Of 28 patients hospitalized with the chief complaints of liver diseases and/or their complications, the number of cases infected with hepatitis B and C viruses was only 5 (17.9%). On the other hand, for patients with tuberculosis, 13 of 19 cases (68.4%) were hospitalized with the chief complaints associated with symptoms of pulmonary tuberculosis or enlarged lymph nodes. The number of patients with multiple infectious diseases was 9 in total. Conclusion : As expected, the prevalence of some infectious diseases were higher among the homeless inpatients, than non-homeless population. Proper screening tests in order to determine the presence of any infectious diseases among the patients and protect involved medical staff are necessary. Further, the government should take proactive measures to prevent the spread of infectious diseases in the aspect of public health.

항생제 혼합 시멘트 정을 이용한 장관골 감염성 불유합의 이단계 치료

조세현,정순택,박형빈,황선철,하용찬,황인환 대한골절학회 2004 대한골절학회지 Vol.17 No.4

목적: 장관골 감염성 불유합의 치료 시 항생제 혼합 시멘트 정을 이용한 이단계 재건술의 결과를 분석하고자 한다. 대상 및 방법: 1998년 1월부터 2002년 9월까지 장관골 감염성 불유합으로 이단계 재건 수술을 받은 41예 (대퇴골 26예, 경골 15예)를 대상으로 하였다. 일단계 수술에서는 광범위한 변연 절제술, 부골 제거 및 세척술과 기존 고정 장치의 제거 또는 외고정 장치로의 교환을 시행한 후 시공 (dead space)과 불유합 주변 연부조직 내 항생제 혼합 시멘트 정을 삽입하였다. 임상적 감염 증상이 호전된 평균 8.7주 (3주~32주) 후 이단계 재건술로서 Ⅰ군은 내고정 장치 (금속판 5예, 골수강내 금속정 8예), Ⅱ군은 외고정 장치 (Ilizarov 25예, Monofixator 3예)로 각각 고정하고 17예에서는 골내 이동술이나 골 연장술을 시행하였다. 양군 모두 필요한 경우 골 이식과 시멘트 정의 교환을 추가하였다. 추시 기간은 16개월에서 최장 71개월로 평균 45개월 이었다. 치료 결과는 골유합 기간 및 Paley 방법에 의한 방사선상 골유합 상태와 하지 기능으로 평가하였다. 결과: Ⅰ군 13예 전부와 Ⅱ군 28예 중 26예에서 감염의 치료와 골유합을 얻었다. 이단계 재건술 후 골 이식술, 골 소파술, 외고정 핀 교환과 각변형 교정술, 피부 이식 또는 근육 피판 회전술 등의 보조적 시술이 Ⅰ군은 평균 2회, Ⅱ군은 평균 6.2회 추가되었다. 평균 골유합 기간은 Ⅰ군이 19.3주이고 Ⅱ군이 23.1주로 내고정군이 더 빨랐다. 방사선상 Paley 골유합 상태는 Ⅰ군이 우수 8예, 양호 5예이었고, Ⅱ군이 우수 18예, 양호 7예, 보통 1예, 불량 2예 이었다 (p=0.492). 기능적 결과는 Ⅰ군에서 우수 6예, 양호 6예, 보통 1예 이었고, Ⅱ군에서는 우수 10예, 양호 13예, 보통 3예, 불량 2예 이었다 (p=0.267). 결론: 항생제 혼합 시멘트 정의 골수염 치료 효과가 관찰되었으며, 감염이 호전된 후 내고정 장치로 교환해 준 군이 외고정을 유지한 군에 비하여 추가 수술 횟수가 적고, 골유합 기간도 빨랐다. Purpose: To evaluate treatment results between internal na external fixation groups in two-stage reconstruction of infected nonunion of long bones using antibiotics-impregnated cement beads. Materials and Methods: In the first stage, preexisting hardwares were removed and radical debridement was done. The dead space was filled with antibiotics -impregnated cement beads and the nonunion sits was immobilized by external fixation, cast or skeletal traction. In the second stage, all cases were divided into two groups; the nonunion was fixed by internal fixation in group Ⅰ versus external fixation in group Ⅱ. The intervening period between the first and second stage was average 8.7 weeks (range, 3~23 weeks). Results: The follow-up period was average 45 months (range, 16~71 months). Infection control and bone union were achieved in all 13 cases of group Ⅰ. Infection recurred in two of 28 cases in group Ⅱ, one underwent above-knee amputation and the other case was lost in follow-up. The mean number of supportive operations including repeated curettage, augmentation and change of infected pins, angular correction, and soft tissue flap was average 2 and 6.2 times respectively in group Ⅰ and group Ⅱ. Bony union period was average 19.3 and 23.1 weeks in each group. According to Paley's classification, group Ⅰ was similar to group Ⅱ in bony and functional result (p>0.05). Conclusion: Antibiotics-impregnated cement beads provided positive effect on infection control. Internal fixation group showed less number of additional operations and earlier bony union than external fixation group.

초기 성공적인 심폐소생술후 혈청 Interleukin-6 농도의 발현양상

박규남,박승현,황두영,김형국,이환,최경호,이원재,정욱성,김학주,김세경 大韓應急醫學會 1998 대한응급의학회지 Vol.9 No.4

Objective : To investgate patterns of serial serum interleukin-6(IL-6) concentrations after initial successful cardiopulmonary resuscitation, and to access differences in serum IL-6 concentrations in patients with Cerebral Performance Category(CPC, 1-2) and CPC(3-5) at the 5th day after cardiacpulmonary resuscitation(CPR). Methods : We studied prospectively 12 patients with spontaneous circulation after cardiopulmonary resuscitation. Venous blood samples were taken 2, 4, 12, 24, 48 and 72 hours after restoration of spontaneous circulation to measure serum IL-6 levels by the enzyme-linked immunosorbent assay. Results : Serum IL-6 concentrations in the severe neurolgically disabled group(CPC, 3-5) were significantly increased at 2, 24 and 48 hours after restoration of spontaneous circulation compared with the less neurolgically disabled group. Also, serum IL-6 concentrations in the severe neurolgic disabled group showed dual peak at 4 and 24 hours. Conclusion : Our study demonstrates significant increase of serum IL-6 in patients with CPC(3-5) after successful cardiopulmonary resuscitation and the significant correlation between early increase of serum IL-6 and poor neurologic outcome. It suggests that early increase of serum IL-6 can be used as a prognostic marker after successful cardiopulmonary resuscitation.

급성신부전을 동반한 알콜성 횡문근융해증 2례

김영민,오동렬,이원재,김형국,황두영,이환,최경호,정시경,김세경,김영옥 大韓應急醫學會 1998 대한응급의학회지 Vol.9 No.4

Rhabdomyolysis is a biochemical and clinical syndrome caused by lysis of skeletal muscle cell and release of muscle cell contents into the circulation. In addition to traumatic cause, various nontraumatic causes have been reported. Rhabdomyolysis has frequently been associated with seamy aspects of life and society: alcoholic abuse, drug addiction, sadistic drill exercise, war events and attempted suicide. The abuse of alcohol causes many hazards in many organs. One of these is acute alcoholic myopathy that may present as a fulminent syndrome of muscle pain and tenderness associated with rhabdomyolysis and acute renal failure. Because the prognosis of adequately treated rhabdomyolysis is excellent, early recognition and prompt management are essential in emergency situation. We experienced two typical cases of alcohol-induced rhabdomyolysis with acute renal failure and report these cases with literature review.

Human Turbinate Mesenchymal Stromal Cells as a Potential Option for Cartilage Tissue Engineering

( Se Hwan Hwang ),( Sung Won Kim ),( Su Young Kim ),( Sun Hwa Park ),( Hun Jun Lee ),( Mi Young Choi ),( Hea Jin Oh ),( Se Hyeun Kim ),( Jong Won Rhie ),( Dong Il Sun ) 한국조직공학·재생의학회 2011 조직공학과 재생의학 Vol.8 No.6

To produce alternate cell sources for the regeneration of cartilage, human turbinate mesenchymal stromal cells (hTMSCs) were tested by culture for their differentiation potential in three-dimensional scaffolds with conventional chondrogenic ingredients. We also evaluated the effects of co-culture with human septal chondrocytes (hSCs) on the chondroinduction of hTMSCs. We isolated hTMSCs from discarded human inferior turbinate tissue. The expression of mesenchymal stem cell surface markers was assessed by fluorescence-activated cell sorting. hTMSCs were cultured in an open-cell polylactic acid sponge with TGF-β and IGF-1. hSCs were co-cultured with hTMSCs at a 1:1 ratio. Chondrogenic hTMSC differentiation and the efficiency of co-culture with hSCs were analyzed histologically by toluidine blue O staining. Cartilage-specific gene expression and matrix production were evaluated quantitatively by real-time PCR and Western blotting. Surface epitope analysis revealed that the hTMSCs were negative for CD14, CD19, CD34, and HLA-DR, and positive for CD29, CD73, and CD90. hTMSCs cultured in the OPLA scaffold showed high cell expansion and a chondroblastic phenotype, demonstrated by the expression of cartilage-specific genes. The chondroinduced hTMSCs exhibited much higher cartilage-specific matrix production and gene expression than characteristic of hSCs or a 1:1 co-culture of hTMSCs and hSCs. These findings indicate that hTMSCs may be redirected towards a chondrogenic phenotype by in vitro culture when cultured in three-dimensional scaffolds with growth factors such as TGF-β and IGF-1.