1.Proportionality assuption test of Cox's proportional hazards model in survival analysis.
Moo Song LEE ; Keun Young YOO ; Dong Young NOH ; Kuk Jin CHOE
Journal of the Korean Cancer Association 1991;23(4):852-859
No abstract available.
Proportional Hazards Models*
;
Survival Analysis*
2.Evaluation of aniline blue dye method for rapid identification of candida albicans.
Kap Jun YOON ; Won Keun SONG ; In Ho JANG ; Dong Hun SHIN
Korean Journal of Clinical Pathology 1993;13(2):271-274
No abstract available.
Candida albicans*
;
Candida*
3.Clinico-pathological Study on the Skin Appendage Tumors.
Kye Yong SONG ; Dong Hun YOON ; Eui Keun HAM ; Yoo Shin LEE
Korean Journal of Pathology 1989;23(1):111-121
A clinico-pathological study on the true skin appendage tumors was carried on the accumulated cases during pat 11 years from 1976 to 1986 years in the Department of Pathology, Seoul National University Hospital. The results was as follows; 1) Among various benign skin appendage tumors pilomatricoma was the most common benign tumor consisting of 72 out of 244 cases (30.1%), followed by dermoid cyst 48 cases (20.0%), steatocystoma multiplex 37 cases (15.5%), syringoma 33 cases (13.8%) and trichilemmal cyst 19 cases (0.8%). Other benign skin appendage tumors were rarely noted under 3%. Sebaceous carcinoma was most common among malignant skin appendage tumors and no malignant tumor of sweat gland origin was noted. 2) The sex ratio of male to female of the pilomatricoma was 1 : 2.6 and on the face, neck, and extremeties in 1st and 2nd decades. The sex ratio of dermoid cyst was 1 : 1.2 on the face in 1st decade. The sex ratio of steatocystoma multiplex was 1 : 1.9 and on the trunk in 3rd decade. The sex ratio of syringoma was 1 : 7 and on the face in 5th decade. The sex ratio of trichilemmoma was 1 : 1.6 and on the trunk in 5th decade. Other tumors were not avaiable for analysis because of small number. The sex ratio of sebaceous carcinoma was 1 : 2 and on the eyelid in 6th decade
Female
;
Male
;
Humans
;
Cysts
4.Current Status of CPR in Korea.
Korean Journal of Medicine 2007;73(1):4-10
Cardiac Arrest victims are increasing but EMS is not ready for them, in Korea. At this time, we need to know the exact status about the chain of survival of CPR and the outcome after out-of-hospital arrest. More than 90% of out-of-hospital arrest was witnessed, and about a half at home, but bystander CPR was done in only about 10%. EMS is activated by the unified phone number (119), but in only 1%, EMS was dispatched for CPR, nationwide. EMS responders were not educated and organized specific for CPR situation. BLS and equipped AED were not always utilized to whom needed. Pre-hospital ACLS were exceptionally done by first responder. Initial ECG findings, most of which were recorded at Hospital ED(more than 20 minutes after collapse), were VF/Pulseless VT(11-12%), Asystole(63-64%), and PEA(24-26%). Initial ROSC rate was 44-45%, and final Discharge Alive rate was 5-10%. The outcome of out-of-hospital arrest was dependent on bystander CPR and initial ECG finding. Most of lay-person are aware to CPR, but not adequately educated to do CPR when needed. We should organize the efforts to improve the quality of EMS and build up the education system of CPR nationwide, at now.
Cardiopulmonary Resuscitation*
;
Education
;
Electrocardiography
;
Heart Arrest
;
Korea*
;
Out-of-Hospital Cardiac Arrest
5.Development of a Stress Classification Model Using Deep Belief Networks for Stress Monitoring.
Healthcare Informatics Research 2017;23(4):285-292
OBJECTIVES: Stress management is related to public healthcare and quality of life; an accurate stress classification method is necessary for the design of stress monitoring systems. Therefore, the goal of this study was to design a novel stress classification model using a deep learning method. METHODS: In this paper, we present a stress classification model using the dataset from the sixth Korea National Health and Nutrition Examination Survey conducted from 2013 to 2015 (KNHANES VI) to analyze stress-related health data. Statistical analysis was performed to identify the nine features of stress detection, and we evaluated the performance of the proposed stress classification by comparison with several stress detection models. The proposed model was also evaluated using Deep Belief Networks (DBN). RESULTS: We designed profiles depending on the number of hidden layers, nodes, and hyper-parameters according to the loss function results. The experimental results showed that the proposed model achieved an accuracy and a specificity of 66.23% and 75.32%, respectively. The proposed DBN model performed better than other classification models, such as support vector machine, naive Bayesian classifier, and random forest. CONCLUSIONS: The proposed model in this study was demonstrated to be effective in classifying stress detection, and in particular, it is expected to be applicable for stress prediction in stress monitoring systems.
Classification*
;
Dataset
;
Delivery of Health Care
;
Forests
;
Korea
;
Learning
;
Machine Learning
;
Methods
;
Nutrition Surveys
;
Quality of Life
;
Sensitivity and Specificity
;
Support Vector Machine
6.Three cases of successful pregnancy outcome after intensive care in the patients with complete uterine septum, cervical duplication and longitudinal vaginal septum.
Suk Hoon KIM ; Hee Chul KIM ; Dong Jin LEE ; Ji Hong SONG ; In Ok SONG ; Keun Jai YOO ; In Soo KANG
Korean Journal of Obstetrics and Gynecology 2000;43(5):927-931
Three cases of successful pregnancy outcome after intensive care in the patients with rare mullerian anomaly of complete uterine septum, hypoplastic cervical duplication and longitudinal vaginal septum in infertility clinic are reported. These presented three cases are the reports of supporting the embryologic hypothesis of bidirectional mullerian development which fusion and resorption begins at the isthmus and proceeds simultaneously in both the cranial and caudal directions rather than the classical views of unidirectional(caudal to cranial) mullerian development. Thus, we present here three cases of rare mullerian anomaly and their pregnancy outcomes in an attempt to alert gynecologist to the possible occurrence of such a malformation. In 2 cases, successful pregnancy outcomes were achieved after abdominal or hysteroscopic uterine septotomy before pregnancy and in the last case, successful pregnancy outcome intensive obstetric care was achieved even under uncorrected uterine anomaly and complete removal of uterine septum resulted in uneventful postoperative courses at the same time of cesarean section.
Cesarean Section
;
Female
;
Humans
;
Infertility
;
Critical Care*
;
Pregnancy
;
Pregnancy Outcome*
;
Pregnancy*
7.A study on the stress distribution of the all ceramic crowns according to the cusp angle of the maxillary first premolar using three dimensional finite element method.
Won Kyu KIM ; Dong Kuk SHIN ; Kie Bum SONG ; Jin Keun DONG
The Journal of Korean Academy of Prosthodontics 2004;42(1):58-72
STATEMENT OF PROBLEM: Clinically, maxillary first premolar has a high risk of fracture. This is thought to be caused by the susceptible figure which the maxillary first premolar has. In other words, sharp cusp angles of the premolar is thought to influence this situation. PURPOSE: This study was to know stress distribution of all-ceramic crown according to the cusp angle. MATERIAL AND METHOD: It was manufactured a three dimensional finite element model simplified maxillary first premolar, and then analyzed stress distribution when cusp angle was each 80 degrees, 90 degrees, 100 degrees, 110 degrees and 120 degrees. RESULTS AND CONCLUSION: 1. The von Misses stress showed that stress decreases as cusp angle increases in the central groove of the occlusal surface. 2. It showed that maximum principal stress was centered at the region of the central groove of the occlusal surface and a region which the force was inflicted. And also it appeared high on the lingual and buccal side of finish line. 3. The X axis of normal stress was focused in the central groove of the occlusal surface. The Y axis normal stress appeared high in the central groove of the occlusal surface, buccal and lingual side. 4. The Stress near the finish line showed a low value compared with stress in the region of the central groove of the occlusal surface. 5. It shows that the most dangerous angle for tooth fracture was on 80 degrees of the cusp angle and low on 120 degrees of its.
Axis, Cervical Vertebra
;
Bicuspid*
;
Ceramics*
;
Crowns*
;
Tooth Fractures
8.Posterior Short-Segment Instrumentation of Thoracic and Lumbar Bursting Fractures: Retrospective study related with Load-Sharing classification.
Kyu Yeol LEE ; Sung Keun SOHN ; Chul Hong KIM ; Chang Keun SONG
Journal of Korean Society of Spine Surgery 2001;8(4):497-503
STUDY DESIGN: The authors designed the retrospective study with the Load-Sharing Classification in 47cases of the bursting thoracic-lumbar fractures, which were operated using the pedicle screws. OBJECTIVE: To judge the effectiveness of posterior short segment instrumented fusion in thoracic-lumbar fractures according to the Load-Sharing classification. MATERIAL AND METHOD: From 1995 through 1998, 47 patients who had been operated with short segment transpedicular instrumentation including fractured vertebra were selected and they were divided two groups, one below 6 point of Load-Sharing score, the other above 7 point. In follow up of average 39 months, the guide of reduction loss, which include the change of anterior vertebral body height and sagittal index were analysed statistically with the Student T-test at the postoperative time and the last follow-up time. RESULTS: In group below 6 point, the average of anterior vertebral body height was 56.2% before the operation and reduced 77.6% after the operation and measured 76.4% at final follow-up. The reduction loss was 1.2%. The sagittal index of preoperative 19.4degree became 10.6degree after the operation and measured 11.8degree at the last follow-up. The loss of correction angle was 1.2degree . In the other group above 7 point, anterior vertebral body height was average 51.7% before the operation and reduced 75% after the operation and measured 71.2% in last follow up, so reduction loss was 3.8%. Sagittal index was average 21.6degree before the operation and corrected 12.6 after the operation and measured 14.6degree in last follow up. All of 19 patients with neurologic deficits improved by over the one Frankel grade except grade A. CONCLUSION: Although the additional study is needed, there were no significant difference of statistical analysis about indexes between two groups.
Body Height
;
Classification*
;
Follow-Up Studies
;
Humans
;
Neurologic Manifestations
;
Retrospective Studies*
;
Spine
9.Comparative Analysis of arterial Gases and Acid-base status in Patients with Congenital and Acquired Heart Disease at Preoperative Period, During Extracorporeal Circulation, and Postoperative Period.
Dong Seok LEE ; Bong Keun LEE ; Song Myung KIM
The Korean Journal of Thoracic and Cardiovascular Surgery 2001;34(11):831-842
BACKGROUND: Patients with cardiac diseases who have structural defects in their heart bring about metabolic insult such as preoperative acid-base imbalance. Cardiac operation requires many nonphysiologic procedures such as extracorporeal circulation, hypothermia, and hemodilution. We studied the acid-base status of surgical heart diseases pre-operatively, during extracorporeal circulation, and post-operatively and researched the treatment indications of acid-base disturbances. MATERIAL AND METHOD: From January 1997 to May 1999, fifty two cases of open heart surgery were carried out under extracorporeal circulation, which divided into a set of pediatric and adult groups, congenital and acquired groups, non-cyanotic and cyanotic groups, The alpha-stat arterial blood gas analysis was done in each group during the preoperative period, during the operation with extracorporeal circulation, and during the postoperative period. RESULT: Before surgery, all patients present metabolic acidosis, PaO2 was low in adult group and acquired group and compensatory respiratory alkalosis was noted in cyanotic group. During extracorporeal circulation, adult group revealed alkalosis and normal in acquired group. Pediatric group presents low PaCO2, metabolic acidosis and respiratory alkalosis. Congenital group and non-cyanotic group showed non-compensatory alkalosis trend and non-compensatory respiratory acidosis were observed in cyanotic group during extracorporeal circulation. Postoperative acid-base status of adult group was recovered to normal and the standard bicarbonate was increased in the acquired group. All of the pediatric, congenital non-cyanotic, and cyanotic groups revealed the lack of buffer base. CONCLUSION: In Preoperative period, correction of metabolic acidosis was required in pediatric, congenital and non-cyanotic groups, while treatment of metabolic acidosis and low PaCO2 were required in adult and acquired groups. In the cyanotic group, metabolic acidosis and respiratory alkalosis needed to be corrected preoperatively. Using the extracorporeal circulation, minimal correction was required except acquired group which showed normal acid-base balance. In postoperative period, restriction of bicarbonate was required for acquired group while increase of buffer base was required for pediatric, congenital, non-cyanotic, and cyanotic groups.
Acid-Base Equilibrium
;
Acid-Base Imbalance
;
Acidosis
;
Acidosis, Respiratory
;
Adult
;
Alkalosis
;
Alkalosis, Respiratory
;
Blood Gas Analysis
;
Extracorporeal Circulation*
;
Gases*
;
Heart Diseases*
;
Heart*
;
Hemodilution
;
Humans
;
Hypothermia
;
Postoperative Period*
;
Preoperative Period*
;
Thoracic Surgery
10.On the marginal fidelity of all-ceramic core using CAD/CAM system.
Dong Keun KIM ; Ju Hwan LIM ; Heon Song LIM
The Journal of Korean Academy of Prosthodontics 2003;41(1):20-34
Novel methods producing supplementary and prosthetic material by cutting or discharge processing via computer design have been proposed as alternatives for traditional casting methods and are being utilized for commercial purposes. The CAD/CAM system used in dentistry can be classified into three-dimensional input of target values, restoration design, and material processing. The marginal fidelity in production of In-Ceram core has important clinical implications and is a key consideration issue in CAD/CAM production as well. Through this research, the author arrived at the following conclusion after conducting comparison analysis of marginal fidelities between the In-Ceram core produced via CAD/CAM and that produced through the traditional method: 1. In the cases of mesial, distal, and lingual margins, the core margins via CAD/CAM produced lower values than those via the traditional method, but the differences were found to be statistically insignificant. 2. In the case of labial flange, the core margins via CAD/CAM produced lower values than those via the traditional method and the differences were found to be statistically significant. (p<0.05) 3. In comparision with overall marginal fidelity, the core margins via CAD/CAM produced lower values than those via the traditional method, but the differences were found to be statistically insignificant. 4. Among the core margins produced via the traditional method did not have statistically significant differences but for those produced via CAD/CAM had statistically significant differences between labial and lingual sides and between labial and mesial sides. (p<0.05)
Dentistry