• Korean Journal of Crystallography
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• v.1 no.1
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• pp.1-7
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• 1990

It is shown that the symmetry of the incommensurate phase in Ba2NaNb5O15(BSH) belongs to the four dimensional superspace group C from an analysis of the systematic extinction or the rxtra reflections due to the incommensllrate structure. The resulting superstructure is characterizetl by the space group Ima2(C3l) and the origin of the incommensurability in BSN is briefly discussed. Especially. HREM image have shown the prrscnce of discommensurations. In addition. a group-theoretical consideration of structural phase transitions in BSN is suggested.

• The Pure and Applied Mathematics
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• v.11 no.4
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• pp.275-285
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• 2004

In this paper, the time series models for the number of reported death claims of compulsory automobile liability insurance in Korea are studied. We found that IMA${(0, 1, 1)}\;{\times}\;{(0, 1, 1)}_{12}$ would the most appropriate model for the number of reported claims by the Box-Jenkins method.

• Journal of Korean Foot and Ankle Society
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• v.1 no.1
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• pp.11-14
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• 1997

Hallux valgus is a complex deformity which contains static subluxation of the first metatarsophalangeal joint with lateral deviation of the great toe and medial deviation of the first metatarsal bone. Among the several parameters, radiographic indices are the important ones in the choice of the treatment method. Even though, the normal values of the western peoples are already estabilished, there was no standard values for Korean who has different genetics, and cultural background, till now. So, we tried to estimate the noraml values of the HVA (hallux valgus angle ), IMA ( Intermetatarsal angle) and DMAA (Distal Metatarsal Articular surface Angle) in a normal adult. Fifty normal adult (each 25 male and female) were chosen and took 100 cases of foot radiograph and radiologic indices of the hallux valgus were measured. Average age at the investigation was 34.5 years old. The average HVA is $13.3^{\circ}$, IMA is $8.5^{\circ}$ and DMAA is $34.6^{\circ}$.

• Journal of Electrochemical Science and Technology
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• v.9 no.1
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• pp.69-77
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• 2018

Aluminum electrodeposition was carried out in dimethylsulfone ($DMSO_2$) baths containing 6.2-28.3 mol% $AlCl_3$ at 403 K. The electrochemically active species for Al electrodeposition in $DMSO_2$ baths were investigated. Electrochemical behavior of the electrolyte and the deposition mechanism were studied via cyclic voltammetry (CV). Properties of the deposits were assessed by scanning electron microscopy with energy-dispersive X-ray spectroscopy and X-ray diffraction. In addition, structures of the ionic complexes formed with aluminum in the bath were characterized by $^{27}Al$ nuclear magnetic resonance (NMR) spectroscopy. NMR spectra revealed that all baths contained two ionic species: $AlCl_4{^-}$ and $[Al(DMSO_2)_3]^{3+}$. Al electrodeposited when the $[Al(DMSO_2)_3]^{3+}$ concentration was the highest (23.3 mol% $AlCl_3$) exhibited fine grain sizes, relatively smooth surfaces, and high purities.

• Journal of Korean Foot and Ankle Society
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• v.8 no.2
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• pp.131-137
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• 2004

Purpose: We evaluated the results of various surgical treatments for hallux valgus with and without attempting to correct sesamoid subluxation. Materials and Methods: Thirty-one cases in 26 patients were involved in this study: Group I (15 cases) - surgery performed only to correct the hallux valgus angle (HVA) and the first-second intermetatarsal angle (IMA) in AP view; Group II (16 cases) - surgery performed to correct HVA and IMA and also to reduce the subluxation of sesamoid. The degree of sesamoid subluxation was measured from a pre- and intraoperative sesamoid tangential views. For both groups, we analysed the status of the sesamoid in pre- and postoperative radiographs and performed clinical evaluation using the Mayo clinic forefoot scoring system. Results: The average amount of correction during postoperative period and loss of correction at last follow-up in the sesamoid tangential view were as follows: soft tissue procedures (5 cases) - group I: grade $1.0{\pm}0.4/1.5{\pm}0.3$ and group II: grade $2.0{\pm}0.9/0.5{\pm}0.08$; chevron osteotomy (12 cases) - group I: grade $1.0{\pm}0.5/1.2{\pm}0.3$ and group II: grade $2.2{\pm}0.7/0.9{\pm}0.2$; proximal metatarsal osteotomy (14 cases) - group I: grade $4.0{\pm}0.4/1{\pm}0.2$ and group II: grade $4.7{\pm}1.1/0.8{\pm}0.1$. In clinical evaluation, more than 93% of the feet had a good result in both groups. The analysis of these data for each treatment type did not show any statistically significant differences between groups I and II. Conclusion: The radiologic and clinical results did not validate our attempts to reduce the sesamoid during surgery.

• Journal of Korean Foot and Ankle Society
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• v.11 no.1
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• pp.28-34
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• 2007

Purpose: To evaluate the clinical and radiographical results of triple osteotomy as a treatment for adult hallux valgus with highly increased distal metatarsal articular ankle (DMAA). Materials and Methods: From October 2003 to April 2005, we retrospectively reviewed 7 hallux valgus patients (3 cases: moderate, 4 cases: severe) treated with triple osteotomy and followed-up for more than 1 year after operation. The mean follow up was 15.1 months. The hallux valgus angle (HVA), intermetatarsal angle (IMA), distal metatarsal articular angle (DMAA) and the length of 1 : 2 metatarsal bone were measured. Proximal chevron osteotomy and distal biplanar chevron osteotomy were done in 1st metatarsal bone. Akin osteotomy was added to the base of the proximal phalanx. The clinical result was assessed using the AOFAS Hallux score, tenderness on the medial eminence, ROM of 1st metatarsophalangeal joint, calluses and patient satisfaction. Results: The mean HVA and IMA was improved from $37.5^{\circ}$ and $13.4^{\circ}$ to $10.5^{\circ}$ and $6.2^{\circ}$ respectively. The mean DMAA was corrected from $34.2^{\circ}$ to $11.2^{\circ}$ and mean shortening of 1st metatarsal was 2.4 mm (0.9-5.8 mm). The mean AOFAS hallux score was improved from 66.4 to 92.5 and VAS score (pain on the medial eminence) from 4.3 points to 0.4 points. Metatarsalgia disappeared in all cases and there was no complications such as necrosis of the metatarsal head. Conclusion: Triple osteotomy for adult hallux valgus with a highly increased DMAA is effective and should be considered as a part of the treatment armamentarium.

• Journal of Korean Foot and Ankle Society
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• v.17 no.4
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• pp.302-308
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• 2013

Purpose: To present clinical results of proximal first metatarsal opening wedge osteotomy and low profile plate fixation in hallux valgus deformity. Materials and Methods: Thirty-two patients (39 feet) underwent surgery for hallux valgus deformity. Fourteen patients (18 feet; Group A) underwent proximal first metatarsal opening wedge osteotomy fixed with low profile titanium plate ($Arthrex^{(R)}$), and 18 patients (21 feet; Group B) underwent proximal chevron osteotomy with two K-wires. Improvement in hallux valgus angle (HVA), 1, 2 intermetatarsal angle (IMA), range of motion of 1st metatarsophalangeal joint, VAS score, and the length of first metatarsal on weight-bearing radiograph were evaluated preoperatively and at final follow-up. Results: HVA improved from $36.2{\pm}6.6$ degrees to $11.7{\pm}5.1$ degrees, and 1, 2 IMA improved from $15.7{\pm}2.6$ degrees to $7.2{\pm}1.9$ degrees. VAS score improved from $7.2{\pm}1.2$ to $1.4{\pm}0.9$. There were no significant differences clinically and radiologically. Conclusion: Proximal first metatarsal opening wedge osteotomy with stable fixation using low profile plate may be an effective surgical option for correction of hallux valgus deformity.

• Journal of Korean Foot and Ankle Society
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• v.19 no.3
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• pp.97-101
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• 2015

Purpose: The purpose of this study was to analyze the clinical results of application of bioabsorbable screws in hallux valgus surgery using modified Mau osteotomy. Materials and Methods: We retrospectively reviewed medical records of 25 patients. Operations were performed between May 2013 and January 2014. We performed 33 modified Mau osteotomies and fixed using bioabsorbable screws. Mean age of patients was 52 years (range 19 to 71). Mean follow up duration was 13.2 months (range 12.3 to 18.9). The clinical evaluations included pain visual analogue scale (VAS) score, American Orthopaedic Foot and Ankle Society (AOFAS) score, and satisfaction score. Weight bearing anteroposterior radiographs were taken for measurement of hallux valgus angle (HVA), intermetatarsal angle (IMA), and distal metatarsal articular angle (DMAA). All radiographs were evaluated in order to detect complications related to bioabsorbable screws such as osteolysis, cyst formation, and fixation failure. Results: The mean pre- and postoperative pain VAS scores were 4.0 and 1.7 (p<0.05). The mean AOFAS score improved from 52.6 to 82.8 (p<0.05). Preoperative HVA and IMA were 31.2 and 13.9, respectively. Postoperative HVA and IMA were 5.2 and 6.2 (p<0.05). The DMAA increased from 7.8 to 9.9 (p<0.05). There was one case of superficial wound infection and one loss of correction, and no case of osteolysis, cystic formation around the screw, or deep infection. All patients showed union without fixation failure. Conclusion: The clinical and radiological evaluation of this study demonstrates reliable results without fixation failure or allergic reaction. The use of bioabsorbable screw appears not to be inferior to metal screw fixation in hallux valgus surgery.

• Journal of Korean Foot and Ankle Society
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• v.14 no.1
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• pp.11-15
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• 2010

Purpose: The purpose of this study was to retrospectively analyze the clinical and radiologic results of the proximal crescentic osteotomy for moderate to severe hallux valgus deformity. Materials and Methods: Between March 2001 and March 2008, 55 patients (71 feet) who had undergone crescentic osteotomy and distal soft tissue procedure for hallux valgus were followed up for more than one year. The average follow-up period was 15.8 months (12~28 months) and the average age at the time of surgery was 49.8 years (20~69 years). We analyzed the hallux valgus angle (HVA), the first-second intermetatarsal angle (IMA), the length of 1st metatarsal bone and the position of medial sesamoid in preoperative and the last follow-up radiographs. The American Othopeaedic Foot and Ankle Society (AOFAS) score and patient satisfaction were measured by modifying Johnson's method which were used for clinical outcome assessments. Results: The HVA and the IMA were 36.2 and 15.8 degrees preoperatively, and 10.8 and 3.9 degrees at the last follow-up, respectively. The amount of shortening of 1st metatarsal bone averaged $2.3{\pm}1.1$ rum postoperatively. The medial sesamoid position improved from a preoperative average of grade 6.6 to the last follow-up average of grade 1.9. The AOFAS score improved from a preoperative average of 45.3 points to an average 90.6 points at the last follow-up. The patient's satisfaction was completely satisfied in 61 cases (85.9%), satisfied with minor reservations in 6 cases (8.5%), satisfied with major reservations in 2 cases (2.8%), and dissatisfied in 2 cases (2.8%). Conclusion: Proximal crescentic osteotomy produced satisfactory results for moderate to severe hallux valgus deformity.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.15 no.26
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• pp.119-124
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• 1992

본 논문은 장치산업에서 적용되는 다변량 EWMA 공정제어와 통계적 공정감시 통합시스템을 제안한다. 본 논문에서 제안한 통합시스템은 자동공정제어(APC)의 예측, 조정기능과 통계적 정정감시(SPM)의 이상점 발견 및 제거등의 각각의 장점을 이용하였다. 기존의 다변량 EWMA연구는 데이타간의 독립성을 가정하였으나 본 논문은 데이타간의 종속적인 형태인 IMA(1,1)모델을 대상으로 하였다.