• Journal of the Korean Data and Information Science Society
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• v.26 no.2
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• pp.525-533
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• 2015

Modern production process is a very complex structure combined observations which are correlated with several factors. When the error signal occurs in the process, it is very difficult to know the root causes of an out-of-control signal because of insufficient information. However, if we know the time of the change, the system can be controlled more easily. To know it, we derive a maximum likelihood estimator (MLE) of the change point in a process when observations are from a multivariate IMA(1,1) process by monitoring residual vectors of the model. In this paper, numerical results show that the MLE of change point is effective in detecting changes in a process.

• IEMEK Journal of Embedded Systems and Applications
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• v.9 no.3
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• pp.183-191
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• 2014

The software running on avionic system is required to be highly reliable and productive. The air transport industry has developed ARINC Specification 653(ARINC653) as a standardized software requirement of avionics computers. The document specifies the interface boundary between avionics application software and the core executive software. Dependability in ARINC 653 is provided by spatial and temporal partitioning whilst fault-tolerance is provided by health monitoring mechanism. Legacy real-time operating systems are used to support ARINC653 health monitor on integrated modular avionics(IMA). However, legacy real-time operating systems are costly and difficult to modify the kernel. In this paper, we suggest a Linux-based ARINC653 health monitor. Functionalities to support ARINC653 health monitor are implemented as a Linux kernel module and its performance is evaluated.

• Journal of the Korean Data and Information Science Society
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• v.15 no.2
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• pp.285-295
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• 2004

Statistical process control(SPC) and engineering process control(EPC) are two complementary strategies for quality improvement. An integrated process control(IPC) can use EPC to reduce the effect of predictable quality variations and SPC to monitor the process for detection of special causes. In this paper we assume an IMA(1,1) model as a disturbance process and an occurrence of a level shift in the process, and we consider the economic performance for applying an EWMA chart to monitor MMSE-controlled processes. The numerical results suggest that the IPC scheme in an IMA(1,1) disturbance model does not give additional advantages in the economic aspect.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2000.04a
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• pp.13-20
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• 2000

• 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.12 no.1
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• pp.1-8
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• 2008

Purpose: To evaluate the value and limitation of modified Mau osteotomy through the review of 30 feet treated by this procedure. Materials and Methods: We retrospectively analyzed 30 cases treated with modified Mau osteotomy since 2002. The mean duration of follow-up was 10 months. We reviewed medical records to describe each case and select several clinical factors which related with surgical procedure and could influence on final results. We measured radiographic parameters such as hallux valgus angle (HVA), intermetatarsal angle (IMA), distal metatarsal articular angle (DMAA), sesamoid position and also assessed clinical outcomes by AOFAS score and satisfaction degrees. Results: The mean preoperative HVA and IMA were $40.4^{\circ}$, $17.4^{\circ}$ and the mean amounts of correction were $31.2^{\circ}$ and $11.5^{\circ}$. Amounts of delayed loss of correction were 16.8% in HVA and 19.2% in IMA. Initial HVA, rotational angle and translation distance of the distal fragment, stability of fixation, first ray instability were revealed as significant factors for the final result from this procedure. DMAA was increased by rotation of the distal fragment and decreased by adding translation on the rotation. Conclusion: Modified Mau osteotomy is an effective procedure to get enough correction. But, it is important to try to avoid excessive rotation of the distal fragment because it may worse joint congruity. It may be worthwhile to pay close attention to the direction of saw and stability of fixation.

• Journal of Advanced Navigation Technology
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• v.18 no.5
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• pp.437-444
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• 2014

The integrated modular avionics (IMA) system has quite a number of line repalceable moduels (LRMs) in a cabinet. The LRM performs functions like line replaceable units (LRUs) in federated architecture. The video processing module (VPM) acts as a video bus bridge and gateway of ARINC 818 avionics digital video bus (ADVB). The VPM is a LRM in IMA core system. The ARINC 818 video interface and protocol standard was developed for high-bandwidth, low-latency and uncompressed digital video transmission. FPGAs of the VPM include video processing function such as ARINC 818 to DVI, DVI to ARINC 818 convertor, video decoder and overlay. In this paper we explain how to implement VPM's Hardware. Also we show the verification results about VPM functions and IP core performance.

• Journal of Korean Foot and Ankle Society
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• v.9 no.1
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• pp.1-8
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• 2005

Purpose: We compared the bony arrangements of the forefoot in 2 different years, 1982 and 2004, to determine any changes with time period of 22 years. Materials and Methods: The radiographs of 200 normal Korean adults, 100 male and 100 female volunteers, were evaluated both in 1982 and 2004. The radiographic results were evaluated with as follows; hallux valgus angle (HVA), intermetatarsal angle (IMA), morphology of metatarsal head and relative anterior protrusion of the metatarsals and the phalanges. The mean ages were 38 years (23-52years) in 1982, and 37 years (24-50years) in 2004. Results: The mean of HVA decreased from 15.6 degrees in 1982 to 14.3 degrees in 2004 (p=0.047), and the mean of IMA increased from 8.0 degrees in 1982 to 9.4 degrees in 2004 (p=0.031). The morphology of metatarsal head and relative anterior protrusion of the metatarsals and the phalanges were not different between the two study years. Conclusion: Comparing with those of 1982 measurements, we found an increase of IMA and a decrease of HVA. A prospective study may be needed to illuminate course of the changes.

• Journal of Korean Foot and Ankle Society
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• v.12 no.2
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• pp.140-144
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• 2008

Purpose: The purpose of this study is to compare the treatment outcomes of distal chevron osteotomy with those of proximal metatarsal closing wedge osteotomy in patients with moderate severity hallux valgus. Materials and Methods: Forty-two patients (51 feet) who were underwent either distal chevron osteotomy (Group I, 22 patients, 27 feet) or proximal metatarsal closing wedge osteotomy (Group II, 20 patients, 24 feet) for the correction of moderate hallux valgus deformity were evaluated retrospectively. We assessed the radiographic results with several parameters including hallux valgus angle (HVA), intermetatarsal angle (IMA) and distal metatarsal articular angle (DMAA). And clinical results with modified AOFAS score at last follow-up. Results: There were no significant differences in IMA, HVA and DMAA between two groups preoperatively. We can achieve the good results with both procedures, but mean HVA and IMA of group II was significantly lower than those of group I. There was some loss of correction in group I at the last follow-up. There was no significant difference in clinical results according to modified AOFAS scoring between two groups at the last follow-up. Conclusion: The proximal metatarsal closing wedge osteotomy for the hallux valgus with moderate severity is better treatment option to achieve better radiographic correction and to prevent loss of correction or recurrence than distal chevron osteotomy.

• Journal of Korean Foot and Ankle Society
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• v.20 no.4
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• pp.158-162
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• 2016

Purpose: To evaluate the radiological and clinical effects of early weightbearing after distal reverse oblique osteotomy of bunionette. Materials and Methods: Between 2009 and 2015, 52 patients who underwent surgical treatment at our hospital for bunionette deformity with a minimum follow up of one year were included in the study. Postoperatively, foot cast was applied and full weightbearing was permitted in 28 patients. And short leg splint was applied with only partial weightbearing using crutches allowed in 24 patients. Clinical scores were evaluated. Radiologically, the 4th~5th intermetatarsal angle (IMA), and 5th metatarsophalangeal angle (MPA) were analyzed preoperatively and at the final follow up visit. Results: The visual analogue scale and American Orthopaedic Foot and Ankle Society scores improved in the partial weightbearing group and full weightbearing group, but without significant differences. The average 4th~5th IMA and average 5th MPA correction also did not showed significant differences between the partial weightbearing group and full weightbearing group. Moreover, the full weightbearing group did not encourage non-union rate compared with the partial weightbearing group. Conclusion: Effective bone union may be achieved through early weightbearing, resulting in better clinical outcomes. It is considered that early weightbearing did not have any effect on the changes of IMA and bone union.