• Archives of Reconstructive Microsurgery
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• v.18 no.2
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• pp.79-83
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• 2009

Purpose: Avulsion injuries of digits have been presented for a long time as complex management problems. Despite of microsurgical advances, it is difficult to achieve good functional results and their management remains somewhat controversial. However, in a finger there are three transverse digital palmar arches. The middle and distal transverse digital palmar arches are consistently large(almost 1 mm) and may be used for arterial vessel repairs either proximally or distally, depending on the length and direction needed. 39-year-old man presented with avulsion amputation of the ulnar three digits, was operated using only arterial anastomosis with rerouting the transverse digital palmar arches. Methods: Replantation was performed using the artery-only technique. Because the digital arteries had been damaged, we did that the transverse digital palmar arches were transposed in an inverted Y to I configuration and were lengthened with rerouting them for the purpose of direct anastomosis of the digital artery. Venous drainage was provided by an external bleeding method with partial nail excision and external heparin irrigation. Results: The authors conclude that complete avulsion amputations with only soft tissue at the distal to insertion of the flexor digitorum superficialis tendon were salvageable with acceptable functional results. All three fingers survived. Conclusion: With technical advancements, the transverse digital palmar arches play an important role for finger amputation. Three digital palmar arches give us additional treatment option for the finger amputation. In this case, replantation with only-arterial anastomosis was successful and we obtained good aesthetic and functional outcome.

• Animal cells and systems
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• v.16 no.4
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• pp.295-301
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• 2012

Interdigital tissue regression is one of the most well-known examples of embryonic programmed cell death, providing the mechanism behind separation of developing digits. Caspases have been shown to play a key part in this process, with activated caspase-3 localized between the developing digits. In caspase-3 knock-out adult mice, however, the digits are completely separated with no webbing. In other mutants with defects in the apoptotic machinery, such as Apaf1 deficient mice, interdigital tissue regression is initially inhibited but the webbing eventually disappears as alternative/additional cell death mechanisms step in. In order to investigate whether a similar temporal effect occurs after loss of caspase-3, we have used an in vitro approach to inhibit caspase-3 at specific times during digit separation. Previous limb explant culture approaches have encountered problems with proper limb development in culture, and thus a modified technique was used. The new approach enables detailed observation of the effects of caspase-3 inhibition on interdigital regression. Using these methods, we show that caspase-3 inhibition caused a delay in the loss of interdigital tissue compared with control explants, similar to that observed in Apaf1 mutant mice. Along with immunohistochemistry, active caspase-3 positive cells of the interdigital vs. digital regions were measured by flow cytometry. Notably, activated caspase-3 in vivo was found not only in the interdigital mesenchyme but also in the TUNEL negative digit region, supporting a role for caspase-3 in nonapoptotic events.

• Journal of Elementary Mathematics Education in Korea
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• v.23 no.1
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• pp.143-168
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• 2019

Along with the significance of algebraic thinking in elementary school, it has been recently emphasized that the properties of number and operations need to be explored in a meaningful way rather than in an implicit way. Given this, the purpose of this study was to analyze how third graders could understand the properties of operations in multiplication after they were taught such properties through a reconstructed unit of multiplication. For this purpose, the students from three classes participated in this study and they completed pre-test and post-test of the properties of operations in multiplication. The results of this study showed that in the post-test most students were able to employ the associative property, commutative property, and distributive property of multiplication in (two digits) × (one digit) and were successful in applying such properties in (two digits) × (two digits). Some students also refined their explanation by generalizing computational properties. This paper closes with some implications on how to teach computational properties in elementary mathematics.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.10
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• pp.2375-2381
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• 2014

In case the coefficient set of an FIR filter is represented in the canonic signed digit (CSD) format with a few nonzero digits, it is possible to implement high data rate digital filters with low hardware cost. Designing an FIR filter with CSD format coefficients, whose number of nonzero signed digits is minimal, is equivalent to finding sparse nonzero signed digits in the coefficient set of the filter which satisfies the target frequency response with minimal maximum error. In this paper, a compressive sensing based CSD coefficient FIR filter design algorithm is proposed for multiplierless and high speed implementation. Design examples show that multiplierless FIR filters can be designed using less than two additions per tap on average with approximate frequency response to the target, which are suitable for high speed filtering applications.

• Archives of Plastic Surgery
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• v.38 no.5
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• pp.636-641
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• 2011

Purpose: There are multiple dependent variables commonly attributed to survival of replanted digits. The ischemia time is thought to be a clinically relevant factor. However, controversy exists as large hand centers have reported successful replant outcomes independent of ischemic time. In this study, we present a single institution experience on the effect of ischemia time on the survival of completely amputated digits. Methods: A retrospective review of a single institution experience was performed. This cohort included all comers who had suffered complete amputation of a digit (Zone 2-4) and underwent replantation from 2003 to 2009. Demographic information as well as injury mechanism, ischemic time, and replantation outcome were recorded for each patient. Chi-square was used to analyze the result. Results: Mean age was 35.5 years old (2-69). Mean replantation survival was 89.5% (37/317). Survival rates were 94, 88, and 88% in respective groups of 0~6, 6~12, of > 12 hours of ischemia time. In chi-square analysis, there was no difference with $p$ value of 0.257. No other independent patient factors showed statistically significant relationship to replant survival rate. In the group with longest ischemia time (12~18 hours) replant survival rate was 88% (37/42). Conclusion: Prolonged ischemia time is commonly believed to be a contributing factor for replant survival. However, our experience has shown that survival rate is uniform up to 18 hours of ischemia.

• Archives of Plastic Surgery
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• v.38 no.5
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• pp.642-648
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• 2011

Purpose: The recent advances in microsurgical techniques and their refinement over the past decade have greatly expanded the indications for digital replantations and have enabled us to salvage severed fingers more often. Many studies have reported greater than 80% viability rates in replantation surgery with functional results. However, replantation of multi-level amputations still remain a challenging problem and the decision of whether or not to replant an amputated part is difficult even for an experienced reconstructive surgeon because the ultimate functional result is unpredictable. Methods: Between January of 2002 and May of 2008, we treated 10 multi-level amputated digits of 7 patients. After brachial plexus block, meticulous replantation procedure was performed under microscopic magnification. Postoperatively, hand elevation, heat lamp, drug therapy and hyperbaric oxygen therapy were applied with careful observation of digital circulation. Early rehabilitation protocol was performed for functional improvement. Results: Among the 19 amputated segments of 10 digits, 16 segments survived completely without any complications. Overall survival rate was 84%. Complete necrosis of one finger tip segment and partial necrosis of two distal amputated segments developed and subsequent surgical interventions such as groin flap, local advancement flap and skin graft were performed. The overall result was functionally and aesthetically satisfactory. Conclusion: We experienced successful replantations of multi-level amputated digits. When we encounter a multi-level amputation, the key question is whether or not it is a contraindication to replantation. Despite the demand for skillful microsurgical technique and longer operative time, the authors' results prove it is worth attempting replantations in multi-level amputation because of the superiority in aesthetic and functional results.

• Archives of Reconstructive Microsurgery
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• v.11 no.1
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• pp.53-62
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• 2002

Several investigators have reported clinical experience of medial plantar septo-cutaneous flap for reconstruction for soft tissue defect of the hand and digits. Jayme and Hamilton first described the anatomy of superficial branch of medial division of the medial plantar artery used in this flap through cadavaric study in 1997. But, they had a few cases for this flap and there was no anatomic study in Korean. We experienced the reliability of medial plantar septo-cutaneous flap for reconstruction for soft tissue defect of hand and digits through an anatomic study (20 fresh specimens dissected) and clinical application (17 patients). An anatomic study revealed that there were differences in diameter and length of the vessels between Korean and Caucasian. The diameter of vessels in Korean is larger than Caucasian one in each area. Based on this anatomic knowledge, we could harvest this flap safely, and have performed reconstruction on 17 patients with soft tissue defects of hand and digits using a thin, flexible medial plantar septo-cutaneous flap similar to the volar aspect of the hand and digits in anatomical characteristics of the skin and subcutaneous tissue covering. The vessels used for this flap were superficial branches of medial division of the medial plantar artery and vena comitants, or the subcutaneous veins. The mean size of the flap was $2.82cm{\times}4.15cm$. All the flaps survived without significant complications. A medial plantar septo-cutaneous flap possesses several advantages : (1) It is very thin in comparison with other standard free flap; (2) it has two draining venous pathways; (3) it provides a good color and texture match for hand and finger; (4) a good recovery of protective sensation is achievable.

• 대한미세수술학회:학술대회논문집
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• 1992.11a
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• pp.78-78
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• 1992

• The Journal of Korean Institute of Communications and Information Sciences
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• v.18 no.6
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• pp.871-880
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• 1993

Conventional binary addition rules require a carry formation and propagation to the most significant bit, and lead to serial addition. Thus, the carry progapation in a binary addition stands as a hindrance to the full utilization of parallelism optics offers, Optical adders using a modified signed-digit(MSD) number system have been proposed to eliminate the carry propagation chain states to represent the three possible digits of MSD number system must encode three different states to represent the three possible digits of MSD. In the paper, we propose the design of a parallel optical adder based on 2-bit addition rules using the method of symbolic substitution(SS).

• Journal of the Institute of Convergence Signal Processing
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• v.2 no.3
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• pp.24-31
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• 2001

The K-L expansion is a method for compressing dimensions of features and thus reduces computational cost in recognition process. Also This is well known that features can be extracted without much loss of information in the statistical pattern recognition. In this paper, the method that effectively applies K-L(Karhunen-Loeve) expansion to feature parameters of speech is proposed to improve the recognition accuracy of the Korean speech recognition system. The recognition performance of a novel feature parameters obtained by the proposed method(K-L coefficients) is compared with those of conventional Mel-cepstrum and regressive coefficients through speaker independent connected digits recognition experiments. Experimental results showed that average recognition rates using the K-L coefficients with regression coefficients obtained higher accuracy than conventional Mel-cepstrum with their regression coefficients.