• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.2
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• pp.156-162
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• 2008

The fatigue durability test using the actual size beam was performed with a cramp joint in order to apply to the highway bridge deck slab. Three types of beam were investigated for durability performance by considering stress conditions in real bridge deck slabs, 1) A beam with major shear force applied at the joint (RC Type) 2) A beam with major bending moments applied at the joint (PSC Type) 3) A beam with the pure shear applied at the joint. The experiment for beams with cramp joints showed that the cramp joint had enough durability for fatigue regardless of the overlaid length of the looped distribution bars under the current design strength level. Moreover, it was clarified that the enough durability for fatigue under the load repetition was achieved by increasing the joint span grater than 1.5D with the consideration of the deformation due to reduction in joint stiffness.

• Clinics in Shoulder and Elbow
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• v.8 no.1
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• pp.14-18
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• 2005

Purpose: Limitation of motion of the elbow joint due to stiffness affect on life quality of the patients. So contracture of the elbow should be treated as soon as possible. Among the many treatment modalities, we described the result of arthroscopic treatment. Materials and Methods: From Mar. 2000 to Mar. 2003, 40 patients, who received the arthroscopic treatment by author for contracted elbow, were the subjects. We estimated the range of motion (ROM) of elbow joint before and after surgery by goniometer. The clinical result was evaluated by Severance elbow scoring system. The final ROM was evaluated at the point of no further increasement of joint motion. Male ware 30 cases, female ware 7 cases, average 42.6 years old and mean follow up period were 31 months. During arthroscopic treatment we had done release of the joint capsule or resection, synovectomy, removal of loose bodies. We used traditional portals. Results: The avarage preoperative ROM of elbow joint was 72.5 degree(range, 5 - 132 degree) and the increasement of ROM was totally 49.3 degree in flexion 26.5 degree and extension 22.8 degree. There was no other complication. Conclusion: Arthroscopic treatment for contracted elbow permit early joint ROM and it decrease the secondary injury to the elbow joint. Also there are few complications. It is thought to be a good treatment modality in contracted elbow joint.

• Journal of Korean Foot and Ankle Society
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• v.21 no.2
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• pp.55-60
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• 2017

Purpose: Stiffness in the first metatarsophalangeal joint after surgery for hallux valgus has been reported. The goal of this study was to test the efficacy of releasing plantar aponeurosis for improving the range of extension in the first metatarsophalangeal joint that was limited after hallux valgus surgery. Materials and Methods: Thirteen patients (1 man, 12 women [17 feet]; median age, 54.4 years; range, 44~69 years) with limited first metatarsophalangeal joint extension after hallux valgus surgery, who underwent an additional procedure of plantar aponeurosis release between March 2015 and August 2015, were included. Subsequently, the passive range of extension in the first metatarsophalangeal joint was evaluated via knee extension and flexion positions. Hallux valgus angle, inter-metatarsal angle, distal metatarsal articular angle, and talo-first metatarsal angle were measured on weightbearing dorsoplantar and lateral radiographs of the foot preoperatively. Results: The mean range of extension for the first metatarsophalangeal joint improved significantly, from $2.5^{\circ}$ to $40.9^{\circ}$ in the knee extension position (p<0.00). The mean extension range for the first metatarsophalangeal joint also improved, from $18.2^{\circ}$ to $43.2^{\circ}$ in the knee flexion position (p<0.00). In all patients, congruence of the first metatarsophalangeal joint was recovered. Conclusion: Plantar aponeurosis release is an effective additional procedure for improving the extension range of the first metatarsophalangeal joint after hallux valgus surgery.

• Steel and Composite Structures
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• v.21 no.2
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• pp.343-356
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• 2016

As the common cast-in-place construction works fails to meet the enormous construction demand under rapid economic growth, the development of prefabricated structure instead becomes increasingly promising in China. For the prefabricated structure, its load carrying connection joint play a key role in maintaining the structural integrity. Therefore, a novel end plate bolt connecting joint between fully prefabricated pre-stressed concrete beam and high-strength reinforcement-confined concrete column was proposed. Under action of low cycle repeated horizontal loadings, comparative tests are conducted on 6 prefabricated pre-stressed intermediate joint specimens and 1 cast-in-place joint specimen to obtain the specimen failure modes, hysteresis curves, skeleton curves, ductility factor, stiffness degradation and energy dissipation capacity and other seismic indicators, and the seismic characteristics of the new-type prefabricated beam-column connecting joint are determined. The test results show that all the specimens for end plate bolt connecting joint between fully prefabricated pre-stressed concrete beam and high-strength reinforcement-confined concrete column have realized the design objectives of strong column weak beam. The hysteretic curves for specimens are good, indicating desirable ductility and energy dissipation capacity and seismic performances, and the research results provide theoretical basis and technical support for the promotion and application of prefabricated assembly frames in the earthquake zone.

• International journal of advanced smart convergence
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• v.9 no.4
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• pp.26-33
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• 2020

This study measured the downward stepping movement relative to weight change (no load, and 10%, 20%, 30% of body weight respectively of adult male (n=10) from standardized stair (rise of 0.3 m, tread of 0.29 m, width of 1 m). The 3-dimensional cinematography and ground reaction force were also utilized for analysis of leg stiffness: Peak vertical force, change in stance phase leg length, Torque of whole body, kinematic variables. The strategy heightened the leg stiffness and standardized vertical ground reaction force relative to the added weights (p<.01). Torque showed rather larger rotational force in case of no load, but less in 10% of body weight (p<.05). Similarly angle of hip joint showed most extended in no-load, but most flexed in 10% of body weight (p<.05). Inclined angle of body trunk showed largest range in posterior direction in no-load, but in vertical line nearly relative to added weights (p<.001). Thus the result of the study proved that downward stepping strategy altered from height of 30 cm, regardless of added weight, did not affect velocity and length of lower leg. But added weight contributed to more vertical impulse force and increase of rigidity of whole body than forward rotational torque under condition of altered stepping strategy. In future study, the experimental on effect of weight change and alteration of downward stepping strategy using ankle joint may provide helpful information for development of enhanced program of prevention and rehabilitation on motor performance and injury.

• Journal of muscle and joint health
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• v.2 no.2
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• pp.185-196
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• 1995

The purposes of this study are to identify effectiveness of the hospital-based home care project, to manage patients' problems in comprehensive way, to decrease the patients' economical burden to the arthritis patients. The design is nonequivalent control group pretest-posttest design with matched samples in terms of age, sex and disease severity. Fifty two patients were assigned in each of the experimental and control groups in Seoul, Kyunggi, Kangwon and Kwangju. Before the experiment and after 3-month period of experiment of home care, level of pain, duration of morning stiffness, Richie Index, ADL, self-efficacy and depression were measured. Nine patients were excluded from the control group because of denial of participation. Contents of home care provided to the experimental group include distribution of prescribed drugs, assessment of patient's condition and side-reactions of drug, pain control, depression control, nutrition guide, exercise teaching, and family counselling. Patients assigned to the control group visited the outpatient clinic once a month as usual. Null hypotheses were selected because physicians concerned about the ineffective change of patients' conditions due to indirect communication with patients through nurses. Level of pain, Richie Index, ADL, self-efficacy, depression and duration of morning stiffness did not significantly different between two groups as expected. In the experimental group, level of pain, ADL, Richie Index and duration of morning stiffness changed to the positive direction from the pretest to the posttest. However, level of depression and self-efficacy did not show any changes. Ninety percent of patients in the experimental group satisfied with the home care provided to them. Since this is the intermediate report, more detailed and long-term report will be prepared.

• Steel and Composite Structures
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• v.18 no.6
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• pp.1391-1404
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• 2015

A radially retractable roof structure based on the concept of the hybrid grid shell is proposed in this paper. The single-layer steel trusses of the radially foldable bar structure are diagonally stiffened by cables, which leads to a single-layer lattice shell with triangular mesh. Then comparison between the static behavior between the retractable hybrid grid shell and the corresponding foldable bar shell with quadrangular mesh is discussed. Moreover, the effects of different structural parameters, such as the rise-to-span ratio, the bar cross section area and the pre-stress of the cables, on the structural behaviors are investigated. The results show that prestressed cables can strengthen the foldable bar shell with quadrangular mesh. Higher structural stiffness is anticipated by introducing cables into the hybrid system. When the rise-span ratio is equal to 0.2, where the joint displacement reaches the minimal value, the structure shape of the hyrbid grid shell approaches the reasonable arch axis. The increase of the section of steel bars contributes a lot to the integrity stiffness of the structure. Increasing cable sections would enhance the structure stiffness, but it contributes little to axial forces in structural members. And the level of cable prestress has slight influence on the joint displacements and member forces.

• Journal of Korean Foot and Ankle Society
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• v.21 no.1
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• pp.21-26
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• 2017

Purpose: To evaluate the clinical outcome of an operation with early rehabilitation from ankle fracture in accordance with the injury type. Materials and Methods: A total of 136 patients (70 males and 66 females) who underwent surgery and early rehabilitation for ankle fractures between December 2008 and December 2013 were retrospectively reviewed. The average age was 47.9 years, with a range of 18~79 years. The mean follow-up period was 28.7 months, with a range of 24~102 months. All patients were classified in accordance with the Lauge Hansen classification and anatomic fracture site. Moreover, the presence of ligament injuries were documented. A short-leg cast was applied postoperatively for two weeks; thereafter, patients began the range-of-motion exercises after cast removal. Full weightbearing was allowed at 2 weeks postoperatively. Each patient was assessed radiologically and clinically based on the OlerudMolander score, visual analogue scale (VAS) for pain, joint stiffness, and capability of single heel raising. Results: Seventeen patients (12.5%) complained of postoperative pain (VAS score 1~3), and the incidence was higher in patients with trimalleolar fractures or associated ligament injuries. Twenty-three patients (16.9%) complained of postoperative ankle stiffness. The mean Olerud-Molander score was 75.4/80 (range, 55~80). Olerud-Molander scores were lower in patients with ligament injuries than in those with fracture alone. There was no nonunion or fracture displacement even after early weightbearing walking. Conclusion: In this retrospective series, early rehabilitation after surgical restoration of ankle mortise by anatomical reduction and stabilization was shown to be successful. Earlier motion exercise and weightbearing walking can minimize fracture complications like joint stiffness or weakness in ankle fracture.

• Journal of Korean Association for Spatial Structures
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• v.18 no.1
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• pp.45-53
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• 2018

Following the earthquake that shook the city of Gyeongju, Korea, in 2016, it became apparent that research on the safety of cultural heritages against the seismic hazards is necessary in Korea. Predictions of how historically significant stone pagodas would behave the earthquakes anticipated in near future, which are the subject of this study, is also required. In this study, the dynamic characteristics of 15 cultural heritage designated stone pagodas of Korea were investigated, including natural frequency and damping ratio, and the stiffness of the stone material and its contact area were determined using eigenvalue analysis by assuming the stone pagodas to be multi-degree-of-freedom structures. The results of this study enable the structural modeling of stone pagodas using a finite element analysis program and the method is expected to be useful in assessing the structural safety of stone pagodas against vertical loads as well as lateral forces, including earthquakes. Also, by identifying the dynamic characteristics of the structures, the results of this study can be utilized as a nondestructive testing method to determine the rigidity of cultural heritage structures and to identify inherent problems. The natural frequencies of the Korean stone pagodas were measured to be within 3.5~8.3Hz, excluding cases with distinct natural frequency results, and it was determined that the natural frequencies of the stone pagodas are influenced by various parameters including the height and joint stiffness of the structures.

• Structural Engineering and Mechanics
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• v.87 no.2
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• pp.137-149
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• 2023

In this study, to explore the working performance of the CFST split spherical node wind power tower, two groups of CFST split spherical joint plane towers with different web wall thicknesses and a set of space systems were analyzed. The tower was subjected to a low-cycle repeated load test, and the hysteresis and skeleton curves were analyzed. ABAQUS finite element simulation was used for verification and comparison, and on this basis parameter expansion analysis was carried out. The results show that the failure mode of the wind power tower was divided into weld tear damage between belly bar, high strength bolt thread damage and belly rod flexion damage. In addition, increasing the wall thickness of the web member could render the hysteresis curve fuller. Finally, the bearing capacity of the separated spherical node wind power tower was high, but its plastic deformation ability was poor. The ultimate bearing capacity and ductility coefficient of the simulated specimens are positively correlated with web diameter ratio and web column stiffness ratio. When the diameter ratio of the web member was greater than 0.13, or the stiffness ratio γ of the web member to the column was greater than 0.022, the increase of the ultimate bearing capacity and ductility coefficient decreased significantly. In order to maximize the overall mechanical performance of the tower and improve its economy, it was suggested that the diameter ratio of the ventral rod be 0.11-0.13, while the stiffness ratio γ should be 0.02-0.022.