• The Journal of the Petrological Society of Korea
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• v.27 no.3
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• pp.109-120
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• 2018

The distributional characteristics of fault segments in Cretaceous and Tertiary rocks from southeastern Gyeongsang Basin were derived. The 267 sets of fault segments showing linear type were extracted from the curved fault lines delineated on the regional geological map. First, the directional angle(${\theta}$)-length(L) chart for the whole fault segments was made. From the related chart, the general d istribution pattern of fault segments was derived. The distribution curve in the chart was divided into four sections according to its overall shape. NNE, NNW and WNW directions, corresponding to the peaks of the above sections, indicate those of the Yangsan, Ulsan and Gaeum fault systems. The fault segment population show near symmetrical distribution with respect to $N19^{\circ}E$ direction corresponding to the maximum peak. Second, the directional angle-frequency(N), mean length(Lm), total length(Lt) and density(${\rho}$) chart was made. From the related chart, whole domain of the above chart was divided into 19 domains in terms of the phases of the distribution curve. The directions corresponding to the peaks of the above domains suggest the directions of representative stresses acted on rock body. Third, the length-cumulative frequency graphs for the 18 sub-populations were made. From the related chart, the value of exponent(${\lambda}$) increase in the clockwise direction($N10{\sim}20^{\circ}E{\rightarrow}N50{\sim}60^{\circ}E$) and counterclockwise direction ($N10{\sim}20^{\circ}W{\rightarrow}N50{\sim}60^{\circ}W$). On the other hand, the width of distribution of lengths and mean length decrease. The chart for the above sub-populations having mutually different evolution characteristics, reveals a cross section of evolutionary process. Fourth, the general distribution chart for the 18 graphs was made. From the related chart, the above graphs were classified into five groups(A~E) according to the distribution area. The lengths of fault segments increase in order of group E ($N80{\sim}90^{\circ}E{\cdot}N70{\sim}80^{\circ}E{\cdot}N80{\sim}90^{\circ}W{\cdot}N50{\sim}60^{\circ}W{\cdot}N30{\sim}40^{\circ}W{\cdot}N40{\sim}50^{\circ}W$) < D ($N70{\sim}80^{\circ}W{\cdot}N60{\sim}70^{\circ}W{\cdot}N60{\sim}70^{\circ}E{\cdot}N50{\sim}60^{\circ}E{\cdot}N40{\sim}50^{\circ}E{\cdot}N0{\sim}10^{\circ}W$) < C ($N20{\sim}30^{\circ}W{\cdot}N10{\sim}20^{\circ}W$) < B ($N0{\sim}10^{\circ}E{\cdot}N30{\sim}40^{\circ}E$) < A ($N20{\sim}30^{\circ}E{\cdot}N10{\sim}20^{\circ}E$). Especially the forms of graph gradually transition from a uniform distribution to an exponential one. Lastly, the values of the six parameters for fault-segment length were divided into five groups. Among the six parameters, mean length and length of the longest fault segment decrease in the order of group III ($N10^{\circ}W{\sim}N20^{\circ}E$) > IV ($N20{\sim}60^{\circ}E$) > II ($N10{\sim}60^{\circ}W$) > I ($N60{\sim}90^{\circ}W$) > V ($N60{\sim}90^{\circ}E$). Frequency, longest length, total length, mean length and density of fault segments, belonging to group V, show the lowest values. The above order of arrangement among five groups suggests the interrelationship with the relative formation ages of fault segments.

• The korean journal of orthodontics
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• v.25 no.4
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• pp.465-485
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• 1995

The purpose of this study is to locate the proper position of the lower occlusal plane according to individual skeletal pattern. Cephalometric films of 234 subjects of the control group, 358 of the pretreatment group and 358 of the treated group were analyzed to study proper relationships between vertical dimension ratio(VDR) and lower occlusomandibular plane angle(LOM). The control group was divided into two subgroups by the age. The first subgroup consisted of 113 subjects of the age 14 years and under and with the mean age of 10.82 years. The other subgroup consisted of 113 subjects of the age 18 years and above with the mean age of 23.76 years. The pretreatment group was divided into three subgroups by the age. The first subgroup consisted of 274 subjects of the age 14 years and under with the mean age of 11.36 years. The second subgroup consisted of 54 subjects of the age 14 through 18 years with the mean age of 15.4 years. The last subgroup consisted of 30 subjects of the age 18 years and above with the mean age of 21.35 years. The treated group was also divided into three subgroups by the age. The first subgroup consisted of 145 subjects of the age 14 years and under with the mean age of 12.91 years. The second subgroup consisted of 166 subjects of the age 14 through 18 years with the mean age of 15.64 years. The last subgroup consisted of 47 subjects of the age 18 years and above with the mean age of 21.61 years. Cephalometric films of the sample were traced. Measurements were made to a hundredth using a program specifically prepared for this study, and the results were entered into a 486DX PC. Means and Standard deviations of all the veriables were calculated for each group. Correlation coefficients between pertinent variables were calculated. Significance tests on those coefficients, one-way ANOVA and t-tests between variables or groups were performed. On the basis of the results studied above, certain subjects were selected from the control and the treated groups to locate the proper position of the occlusal plane, and designated as the optimal occluaion group. The subjects of this optimal occlusion group had 1-3 mm overbite, 1-3 mm of overjet and less than 1.75 mm of curve of Spee. A total subjects of 187 in this group consisted 104 treated subjects and 83 control group. Regression analysis was carried out between VDR and LOM, and regression equations were tabulated for this optimal occlusion group. The results were as follows : 1. Highly significant correlations were observed between various variables useful for identifying vertical component of skeletal frame, but any one particular variable did not accurately indicate the magnitude of anterior vertical overbite. 2. Of the variables useful identifying vertical component of skeletal frame, The VDR showed the highest correlation to the LOM. 3. Of the total sample, 80 percent had overbite within the normal range, irrespective of VDR. 4. The optimal occlusion group was divided into 9 subgroups by the age and the anteroposterior skeletal pattern, and correlation coefficient and determination coefficient between VDR and LOM of each group were calculated. Correlation coefficients and determination coefficients were found to be significantly high in all groups. 5. Regression equation was induced for each of the optimal occlusion group to find proper LOM according to the VDR. 6. It was found that the mean value of the cant of occlusal plane itself is not enough for a diagnosis and a treatment plan. Rather, It is very important to locate the proper occlusal plane for an Individual skeletal pattern.

• Journal of the Korean Orthopaedic Association
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• v.54 no.5
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• pp.427-434
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• 2019

Purpose: This study evaluated the long term clinical and radiographic results and the survival rates of unicompartmental knee arthroplasty (UKA). In addition, the factors affecting the survival of the procedure were analyzed and the survival curve was compared according to the affecting factors. Materials and Methods: Ninety-nine cases of UKA performed between December 1982 and January 1996 were involved: 10 cases with Modular II, 44 cases with Microloc, and 45 cases with Allegretto prostheses. The mean follow-up period was 16.5 years. Clinically, the hospital for special surgery (HSS) scoring system and the range of motion (ROM) were evaluated. Radiographically, the femorotibial angle (FTA) was measured. The survival rate was analyzed using the Kaplan-Meier method. Cox regression analysis was used to identify the factors affecting the survival according to age, sex, body mass index, preoperative diagnosis, and type of implant. The Kaplan-Meier survival curves were compared according to the factors affecting the survival of UKA. Results: The overall average HSS score and ROM was 57.7 and 134.3° preoperatively, 92.7 and 138.4° at 1 year postoperatively, and 79.1 and 138.4° at the last follow-up (p<0.001, respectively). The overall average FTA was varus 0.8° preoperatively, valgus 4.1° at postoperative 2 weeks, and valgus 3.0° at the last follow-up. The overall 5-, 10-, 15- and 20-year survival rates were 91.8%, 82.9%, 71.0%, and 67.0%, respectively. The factors affecting the survival were the age and type of implant. The risk of the failure decreased with age (hazard ratio=0.933). The Microloc group was more hazardous than the other prostheses (hazard ratio=0.202, 0.430, respectively). The survival curve in the patients below 60 years of age was significantly lower than those of the patients over 60 years of age (p=0.003); the survival curve of the Microloc group was lower compared to the Modular II and Allegretto groups (p=0.025). Conclusion: The long-term clinical and radiographic results and survival of UKA using old fixed bearing prostheses were satisfactory. The selection of appropriate patient and prosthesis will be important for the long term survival of the UKA procedure.

• The korean journal of orthodontics
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• v.27 no.2
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• pp.273-282
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• 1997

The purpose of this study was to evaluate changes in mandibular movement patterns after orthognathic surgery in skeletal Class III patients. The sample consisted of 20 Class III malocclusion patients(9 males, 11 females). Just before and after(2-7months) surgery, maximum opening & closing movement, mandibular border movement on sagittal, frontal and horizontal planes were recorded using Sirognathograph & BioPak EGN. On each record, 21 items were measured and statistically analyzed. The results were as follows 1. Angle of protrusive movement on sagittal plane showed greatest change after surgery. Also, as the incisal guidance was established by surgery, straight path of protrusive movement became curved line. 2. Maximum opening distance and maximum antero-posterior distance on maximum opening & closing movement, maximum opening distance on sagittal plane, angle of left lateral excursion on frontal plane were statistically significant after snrgery(p<0.01). 3. Maximum width of lateral excursion on frontal plane, distane of right lateral excursion and angle of maximum left lateral excursion on horizontal plane were statistiraily significant after surgery(p<0.05). 4. Maximum opening distance and maximum antero-posterior distance on maximum opening & closing movement showed significant differences according to post-surgical time(p<0.05). More recovery of range of movement occured in 5-7month group than in 2-3month group. 5. As the occlusal interferences were removed by orthognathic surgery, irregular opening & closing path became smooth curve.

• Journal of Biomedical Engineering Research
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• v.32 no.2
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• pp.165-176
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• 2011

The femoral nerve innervates the quadriceps muscles and its dermatome supplies anteromedial thigh and medial foot. Paralysis of the quadriceps muscles due to the injury of the femoral nerve results in disability of the knee joint extension and loss of sensory of the thigh. A child could walk independently even though he had injured his femoral nerve severely due to the penetrating wound in the medial thigh. We measured and analyzed his gait performance in order to find the mechanisms that enabled him to walk independently. The child was eleven-year-old boy and he could not extend his knee voluntarily at all during a month after the injury. His gait analysis was performed five times (GA1~GA5) for sixteen months. His temporal-spatial parameters were not significantly different after the GA2 or GA3 test, and significant asymmetry was not observed except the single support time in GA1 results. The Lower limb joint angles in affected side had large differences in GA1 compared with the normal normative patterns. There were little knee joint flexion and extension motion during the stance phase in GA1 The maximum ankle plantar/dorsi flexion angles and the maximum knee extension angles were different from the normal values in the sound side. Asymmetries of the joint angles were analyzed by using the peak values. Significant asymmetries were found in GA1with seven parameters (ankle: peak planter flexion angle in stance phase, range of motion; ROM, knee: peak flexion angles during both stance and swing phase, ROM, hip: peak extension angle, ROM) while only two parameters (maximum hip extension angle and ROM of hip joint) had significant differences in GA5. The mid-stance valleys were not observed in both right and left sides of vertical ground reaction force (GRF) in the GA1, GA2. The loading response peak was far larger than the terminal stance peak of vertical ground reaction curve in the affected side of the GA3, GA4, GA5. The measured joint moment curves of the GA1, GA2, GA3 had large deviations and all of kinetic results had differences with the normal patterns. EMG signals described an absence of the rectus femoris muscle activity in the GA1 and GA2 (affected side). The EMG signals were detected in the GA3 and GA4 but their patterns were not normal yet, then their normal patterns were detected in the GA5. Through these following gait analysis of a child who had selective injuries on the knee extensor muscles, we could verify the actual functions of the knee extensor muscles during gait, and we also could observe his recovery and asymmetry with quantitative data during his rehabilitation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.10
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• pp.4725-4732
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• 2012

This paper studies MR16 that can strengthen the strength and make up for the weakness of MR16 by replacing halogen light source using multifaceted Reflector(MR16) with LED light source. To achieve this, developed MR16 for LED applying optical system that four aspheric lens is one sheet. Optical system is designed by optics software and lighting performance of the designed data is predicted lighting simulation program. Also, heatsink's heat radiation analysis program to predict the thermal performance. Finally, optical prototype system based on simulation analysis data is manufactured and the results comparing performance of the developed system and the designed data are follows: Radiation angle was around $50^{\circ}{\sim}60^{\circ}$ in results of simulation analysis and the test of the prototype system. Also, temperature measurement result indicates that the thermal equilibrium is realized after one minute and thirty seconds and heat is generated up $60^{\circ}C$ in all of simulation analysis and the test of the prototype system. Finally, simulation analysis result on light disturbance curve of MR16 is similar to that of performance of the prototype system.

• Composites Research
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• v.30 no.2
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• pp.138-144
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• 2017

Damage sensing of polymer composite films consisting of poly(dicyclopentadiene) p-DCPD and carbon nanotube (CNT) was studied experimentally. Only up to 1st ring-opening polymerization occurred with the addition of CNT, which made the modified film electrically conductive, while interfering with polymerization. The interfacial adhesion of composite films with varying CNT concentration was evaluated by measuring the wettability using the static contact angle method. 0.5 wt% CNT/p-DCPD was determined to be the optimal condition via electrical dispersion method and tensile test. Dynamic fatigue test was conducted to evaluate the durability of the films by measuring the change in electrical resistance. For the initial three cycles, the change in electrical resistance pattern was similar to the tensile stress-strain curve. The CNT/p-DCPD film was attached to an epoxy matrix to demonstrate its utilization as a sensor for fracture behavior. At the onset of epoxy fracture, electrical resistance showed a drastic increase, which indicated adhesive fracture between sensor and matrix. It leads to prediction of crack and fracture of matrix.

• Journal of Korean Society of Steel Construction
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• v.30 no.1
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• pp.1-12
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• 2018

A curved member should resist bending and torsional moments simultaneously even though the primary load is usually supposed to be gravitational load. The torsional moment causes complicate stress state and also can result in early yielding of material to reduce member strength. According to analysis results, the strength of a curved member that has 45 degrees of subtended angle could decrease more than 50% compare to straight girder. Nevertheless, there have been very few of researches related with ultimate strength of curved girders. In this study, various kinds of stiffness about bending, pure torsion and warping were considered with a number of models in order to verify the main factor that affects ultimate behavior of curved girder. Lateral and rotational displacement of curved member were introduced as lateral-torsional-vertical behavior and bending-torsional moment interaction curve was derived. Finally, a strength equation for ultimate moment of horizontally curved steel I-girders subjected to equal end moments based on the interaction curves. The equation could take account of the effect of curvature, unbraced length and sectional properties.

• The korean journal of orthodontics
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• v.3 no.1
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• pp.7-13
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• 1972

Many geometric curves are presented as representative form of normal dental arches by many authors; circle, ellipse, parabola or catenary curve. Among them those except circle seems difficult to be adopted as a guide in ideal arch form construction and practically many orthodontists chose circle as a standard. Author preferred circle of Bonwill's theory in study of anterior teeth alignment of Korean adults. Eighty three dental models which possess proper occlusion and good arch form were selected and copies of their occlusal surfaces obtained by Ricopy machine. The use of Ricopy machine made it possible to draw arch form exactly. Mesiodistal widths of six anterior teeth were measured and they were added to combined mesiodistal width of six anterior teeth. Circle, that include the points of two cuspal tips of canines and one incisal edge of central incisor were drawn. Distances of lateral incisors that are deviated from arc of this circle were measured and classified into four grades by degree and three groups by kind of teeth deviated. By counting the number of samples involved degree of fit of the circle to arch contour of Korean adult was described. Then, size of radius of circle, intercanine width and intermolar width were measured and evaluated their ratios to combined mesiodistal width of six anterior teeth. In normal occlusion of Korean adult anterior teeth seems to be arranged on an arc of circle the radius of which is similar to combined mesiodistal width of six anterior teeth. Intercanine width and intermolar width have rather constant ratios to combined width of six anterior teeth.

• Geotechnical Engineering
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• v.9 no.2
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• pp.41-54
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• 1993

This paper presents the two and three -dimensional stability analysis of nonhom- ogeneous, c-o soil slopes. Potential failure surface is assumed as a logspiral curve refracted in boundaries of layers. In 3-D analysis, rotational soil mass is assumed with a cylindroid central part terminated with plane ends. Seismic force is considered by sesmic intensity. The program developed in this study is compared with the program PCSTABLS. The ratio of three-dimensional minimum factor of safety to two-dimensional case is examined and factor of safety changes are showed for the ratio of cylindroid length to slope height and numbers of slice. On such bases the following conclusions may by made : (1) The program developed in this program is less conservative than the program PCSTABLS. (2) The value of F2 of this study shows the larger differences than that of PCSTABLS with increasing friction angle (3) Factors of safety computed for 3-D geometry differ considerablely from ordinary 2-D factors of safety. Since Fb/F2 exceeds unity, three -dimensional effects tend to increase the factor of safety. (4) As the ratio of three - dimensional failure width of slope height, b/H increase, the value of Fb/Ff decreases and approaches 1.0 when bye is 14. (5) In calculating the factor of safety using the developed program the number of slices is suitable with the ranges of 30-40