1.Study on the Approaching and Examination Methods of the Traffic Accident.
Chan Seong PARK ; Yong Moon YUN ; Gi Tae LEE ; Jae Gueun OH ; Young Shik CHOI
Korean Journal of Legal Medicine 2008;32(1):1-5
Traffic accident leaves various traces on vehicle, road or pedestrians and these can be viewed as the failure mechanism of relatively moving obstacles. This paper introduces tribology and fractography, which are the parts of failure mechanics, as a means of theoretical analysis and approaching methods on the traffic accident. Actual specific traces are introduced as illustrations of tribology and fractogrphy. A verified traffic accident is also introduced as a case report.
Accidents, Traffic
;
Mechanics
2.Change of respiratory mechanics at different intra-abdominal pressures and position change during laparoscopic surgery.
Kyu Yong JANG ; Seok Joo HONG ; Hyun Kyo LIM ; Dea Ja UM
Korean Journal of Anesthesiology 2013;64(6):560-561
No abstract available.
Laparoscopy
;
Respiratory Mechanics
3.A clinical study on anchorage control of molar anchoring spring(MAS) during retraction of the maxillary canine.
Sun Min KIM ; Joon No RHEE ; Joon ROW ; Youn Sic CHUN
Korean Journal of Orthodontics 1998;28(2):269-276
In maxillary canine retraction by means of sliding mechanics, we designed MAS(molar anchoring spring) to prevent anchorage loss and uncontrolled tipping of tooth movement and have applied it in clinical cases. The anchorage control of the maxillary first molar and type of tooth movement of the maxillary canine were studied in 31 subjects. The measurements were made on cephalograms, orthopantomograms and dental casts. The obtained results were as follows. 1. In case of the maxillary first molar, there was a little sagittal anchorage loss, but there was no vertical & transverse anchorage loss. 2. In case of the maxillary canine, there was distal tipping movement and also there was a little intrusion tendency.
Mechanics
;
Molar*
;
Tooth Movement
4.A photoelastic study on the initial stress distribution of the molar anchoring spring(MAS) during retraction of the maxillary canine.
Korean Journal of Orthodontics 1996;26(4):341-348
The efficiency of maxillary canine retraction by means of sliding mechanics along an 0.016 continuous labial arch and an 0.009 inch in diameter with a lumen of 0.030 inch NiTi closed coil spring was compared with that using the same NiTi closed coil spring and Molar Anchoring Spring(MAS) which was designed by author. MAS was made of .017" X .025" TMA wire and was given 60 degree tip-back bend on the wire close to the molar tube. This study was designed to investigate molar and canine root control during retraction into an extraction site with continuous arch wire system. Two techniques were tested with a continuous arch model embedded in a photoelastic resin. A photoelastic model was employed to visualize the effects of forces applied to canine and molar by two retraction mechanics. With the aid of polarized light, stresses were viewed as colored fringes. The photoelastic overview of the upper right quadrant showed that stress concentrations were observed in its photoelastic model. The obtained results were as follows. 1. Higher concentration of compression can be seen clearly at the distal curvature of the canine and mesial curvature of the molar and premolar when NiTi closed coil spring was applied only, which means severe anchorage loss of the molar and uncontrolled tipping of the canine. 2. The least level compression was presented at the mesial root area of the molar and premolar, and mesial root area of the canine when NiTi closed coil spring and MAS were used simultaneously. Especially mesial alveolar crest region of the canine was shown moderate level of compression that means MAS can be used as a appliance for anchorage control and prevention of canine extrusion and uncontrolled tipping during canine retraction.
Bicuspid
;
Mechanics
;
Molar*
5.Monitoring of Respiratory Mechanics during Mechanical Ventilation.
The Korean Journal of Critical Care Medicine 2001;16(2):132-137
No abstract available.
Respiration, Artificial*
;
Respiratory Mechanics*
6.Shoulder Prosthesis Mechanics.
Journal of the Korean Shoulder and Elbow Society 2010;13(1):153-160
PURPOSE: The goal of prosthetic replacement of the shoulder is the restoration of the normal anatomy of the joint. MATERIALS AND METHODS: The physician should review the variations in normal anatomy because it does vary widely and the placement of the prosthetic needs to be modified to accommodate the variations. RESULTS AND CONCLUSION: Several factors including anatomic, prosthetic and surgical ones can lead to the best clinical results, and these are described.
Joints
;
Mechanics
;
Prostheses and Implants
;
Shoulder
7.Anesthetic experience of a patient with severe change on respiratory mechanics in the prone position for spinal surgery.
Soo Kyung LEE ; Min Chul KIM ; Yi Hwa CHOI ; Mae Hwa KANG ; Eunyoung PARK
Korean Journal of Anesthesiology 2014;67(Suppl):S41-S42
No abstract available.
Humans
;
Prone Position*
;
Respiratory Mechanics*
8.Anesthetic experience of a patient with severe change on respiratory mechanics in the prone position for spinal surgery.
Soo Kyung LEE ; Min Chul KIM ; Yi Hwa CHOI ; Mae Hwa KANG ; Eunyoung PARK
Korean Journal of Anesthesiology 2014;67(Suppl):S41-S42
No abstract available.
Humans
;
Prone Position*
;
Respiratory Mechanics*
9.A photoelastic study on the initial stress distribution of the upper anterior teeth retraction using combination loop archwire and sliding mechanics.
Kang Soon YIM ; Jin Woo LEE ; Kyung Suk CHA
Korean Journal of Orthodontics 2004;34(4):303-312
An unfavorable tipping movement can occur during the retraction of anterior teeth because orthodontic force is loaded by brackets positioned far from the center of resistance. To avoid this unfavorable movement, a compensating curved wire or lingual root torque wire is used. The purpose of this study is to investigate, using photoelastic material, the distribution of initial stress associated with the retraction of the incisors according to the degree of the compensating curve, to model changes associated with tooth and alveolar bone structure. The following results were obtained by analysis of the polarizing plate of the effects of initial stress resulting from retraction of the anterior teeth: 1. When the incisors were retracted using combination archwire or sliding mechanics, the maximal polarizing pattern of the apical area decreased as the degree of the compensating curve increased from 0 to 15 to 30. 2. When the incisiors were retracted by the combination archwire or sliding mechanics, the maximal polarizing pattern of t he canine and premolar area increased as the degree of the compensating curve increased from 0to 15to 30. 3. A lower degree of polarizing patterns were associated with the combination archwire technique than the sliding mechanics technique at a given force. The above results indicate that there is no significant difference between the combination loop archwire technique and sliding mechanics, for the retraction of maxillary anterior teeth with decreased lingual tipping tendency by a compensating curve on the arch wire. However, the use of sliding mechanics is more effective for the prevention of lingual inclination of the anterior teeth, because the hook used in sliding mechanics is closer to the center of resistance of the maxillary anterior teeth.
Bicuspid
;
Incisor
;
Mechanics*
;
Tooth*
;
Torque
10.Is Hyperabduction Arm Position in Early Cocking Phase Really Dangerous for Baseball Pitchers?
Jae Hyung LEE ; Byung Hak OH ; Jin Young PARK ; Byoung Kuk LEE ; Tae Hyun YOO ; Hyun Jae CHA
The Korean Journal of Sports Medicine 2019;37(4):130-133
PURPOSE: Certain pitching mechanics is thought to lead pitchers in danger of surgical risk and decrease performance. The objective of this study is to analyze the effect of shoulder hyperabduction position during early cocking phase in association with surgical risk and performance in professional baseball players.METHODS: From 2009 to 2013, total of 93 candidates reached minimum inning qualification. After exclusion criteria (overlapped players, foreign players, age over 31 years, proceed to other league and retirement), 19 players were analyzed with slow-motion pitching video for hyperabduction of the shoulder and hyperpronation of forearm in cocking-phase. Also players were analyzed with innings pitched, earned run average (ERA), walks and hits divided by innings pitched (WHIP) and surgical history with database offered by official Korean Baseball Organization website.RESULTS: Out of total 19 players, nine players had hyperabduction arm movement and 10 players did not. Group with hyperabduction had average age of 24.3 years old, average inning/ERA/WHIP for 5 years were 55 innings/yr, 6.52 ERA/yr and 1.33 WHIP/yr, respectively, and seven players (77%) had surgeries eventually. Group without hyperabduction arm movement had average age of 25.4 years old; average inning, ERA/WHIP for 5 years were 127 1/3 innings/yr, 4.84 ERA/yr, and 1.32 WHIP/yr, respectively and five players (50%) went for surgeries. Player performance (ERA, p=0.66; WHIP, p=0.14) was not statistically influenced by the certain arm position at cocking phase but average inning pitched was statistically affected (p<0.01).CONCLUSION: Hyperabduction of shoulder in early cocking phase of throwing motion does not lead to decrease in performance (ERA, WHIP) but will result in tremendous decline of average IP. Also, risk of surgery is not associated to hyperabduction motion of the shoulder.
Arm
;
Baseball
;
Forearm
;
Mechanics
;
Shoulder