• International Journal of Precision Engineering and Manufacturing
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• 제9권3호
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• pp.22-26
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• 2008

The use of electrical discharge machining (EDM) for micro-machining applications requires particular attention to the machined surface roughness and discharge gap distance, as these factors affect the geometrical accuracy of micro-parts. Previous studies of conventional EDM have shown that selected types of semi-conductive and non-conductive powder suspended in the dielectric reduced the surface roughness while ensuring a limited increase in the gap distance. Based on this, an extension of the technique to micro-EDM was studied Such work is necessary since the introduction of nanopowders suspended in the dielectric is not well understood. The experimental results showed that a statistically significant reduction in the surface roughness value was achieved at particular concentrations of the powder additives, depending on the powder material and the machining input energy setting. The average reduction in surface roughness using a powder suspended dielectric was between 14-24% of the average surface roughness generated using a pure dielectric. Furthermore, when these additive concentrations were used for machining, no adverse increase in the gap distance was observed.

• 한국발생생물학회지:발생과생식
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• 제18권3호
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• pp.167-172
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• 2014

In the present study, muscle tissues were obtained separately from individuals from Atlantic hairtail population (AHP), Gunsan hairtail population (GHP) and Chinese hairtail population (CHP), respectively. The seven decamer primers were used to generate the shared loci, specific, unique shared loci to each population and shared loci by the three hairtail populations. Here, averagely, a decamer primer generated 64.7 amplified products per primer in the AHP population, 55.7 in GHP population and 56.4 in CHP population. The number of unique shared loci to each population and number of shared loci by the three populations generated by genetic analysis using 7 decamer primers in AHP, GHP and CHP population. 119 unique shared loci to each population, with an average of 17 per primer, were observed in the AHP population, and 28 loci, with an average of 4 per primer, were observed in the CHP population. The hierarchical dendrogram point out three main branches: cluster 1 (ATLANTIC 01 ~ ATLANTIC 07), cluster 2 (GUNSAN 08 ~ GUNSAN 14) and cluster 3 (CHINESE 15 ~ CHINESE 21). The shortest genetic distance displaying significant molecular difference was between individuals' CHINESE no. 16 and CHINESE no. 18 (0.045). In the long run, individual no. 01 of the AHP population was most distantly related to CHINESE no. 19 (genetic distance = 0.430). Consequently, PCR analysis generated on the genetic data displayed that the geographic AHP population was widely separated from CHP population, while individuals of CHP population were fairly closely related to those of GHP population.

• The Journal of Korean Physical Therapy
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• 제25권3호
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• pp.136-142
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• 2013

Purpose: The application of transcutaneous electrical nerve stimulation (TENS) is beneficial for joint movements, inhibition of spasticity, and the improvement of walking ability in patients with chronic hemiplegia. This study aimed to identify the effect of the application of TENS to the knee extensor on the affected side with respect to postural-sway distance and velocity during the sit-to stand movement. Methods: We included 19 patients with post-stroke hemiplegia in this study. They underwent measurements during the sit-to stand movement on a force plate with 5 different stimulation dosages applied over 7 s:No TENS, high-frequency and high intensity TENS, high-frequency and low intensity TENS, low-frequency and high intensity TENS, and low-frequency and low intensity TENS The 5 different condition were administered in random order. Results: The group that received TENS application exhibited a significant decrease in path length and average velocity of center of pressure (COP) displacement compared with the group that did not receive TENS application. TENS dosage at low frequency (3Hz) and high intensity yielded a significant decrease in path length, average velocity, mediolateral distance and anteroposterior distance of COP displacement (p<0.05). Conclusion: Our results demonstrated the effectiveness of the application of low-frequency TENS on STS performance. These findings provide useful information on the application of TENS for the reduction of postural sway during the sit-to-stand movement after stroke.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2006년도 추계학술대회 논문집(제1권)
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• pp.31-36
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• 2006

우리나라의 경우 선박조종시뮬레이션을 이용한 선박 통항의 안전성 평가는 흔히 목표점 혹은 목표선 분석으로 이뤄지고 있다. 이 논문에서는 선박조종시뮬레이션 결과에 대하여 목표점 혹은 목표선 분석과 연속분석을 각각 실시하고 이들을 비교 ${\codt}$ 검토하여 각각에 대한 유효성을 제시하고 아울러 각각의 선박의 위치에서 항로 중심에서의 거리가 아닌, 항로경계까지의 최근접거리를 근접도 평가의 한 방법으로 제시하였다.

• 한국지형학회지
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• 제28권2호
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• pp.15-30
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• 2021

This study tried to reveal distribution of incision rate and the factors from fluvial terrace deposits on the western and eastern slopes in the Middle Sobaek Mountain Range, using OSL age dating and topographical analysis. An average incision rate of 0.220 m/ka was estimated in the western slope streams, while the streams on the eastern slope showed a lower average incision rate of 0.121 m/ka. These results seem to indicate that the study area experienced an asymmetric uplift. Patterns of incision rate in the study area were different from those in the Northern Sobaek Mountain Range, probably suggesting that the Sobaek Mountain Range experienced spatially different uplift patterns. Among the factors, which were considered to influence on distribution of incision rate in the study area (e.g., altitude of sampling point, distance from divide, distance from axis, channel width, and bedrock type), distance from axis showed the strongest relationship with incision rate. Therefore, uplift is thought to be the most significant factor in distribution of incision rate in the Middle Sobaek Mountain Range.

• Archives of Plastic Surgery
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• 제35권1호
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• pp.28-35
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• 2008

Purpose: The pedicle of transverse rectus abdominis myocutaneous(TRAM) flap and deep inferior epigastric arterial perforator flap is deep inferior epigastic artery (DIEA) and accurate anatomic knowledge about perforator of DIEA is very important for the elevation of these flap. The authors investigated a detailed vascular network of perforator of DIEA in Koreans. Methods: 24 fresh cadavers were studied. Among them, 15 were examined based on the plain X-ray examination for the distribution and location of perforator of DIEA. And 9 fresh cadavers were examined based on the 3-dimensional computed tomography(CT) study for the distance between ending point of perforator of DIEA and mother artery, the distance between most medial mother artery and midline, the distance between most lateral mother artery and midline, and the running type of perforators of DIEA. Results: Based on the plain X-ray examination, suitable(external diameter$${\geq_-}0.5mm$$) perforators of DIEA are located between the level of umbilicus and 8 cm below it. Based on the 3D-CT study, average distance between the ending point of perforator of DIEA and the mother artery is 30.26 mm on the left, 28.62 mm on the right, respectively. The average distance between most medial mother artery and midline is 17.13 mm on the left, 15.76 mm on the right, respectively. The average distance between most lateral mother artery and midline is 56.31 mm on the left, 50.90 mm on the right, respectively. The main running course of suitable perforators of DIEA is type a, which is a direct musculocutaneous perforator vessel from main vascular axis passing outward to join the subdermal plexus, directly. Conclusion: 3-dimensional computed tomography study as well as plain X-ray examination provided more accurate and detail informations about perforators of DIEA in Koreans. These informations will help us understand the detailed vascular anatomy and operation with ease and safe in the lower abdomen of Koreans.

• 한국패류학회지
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• 제32권4호
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• pp.255-261
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• 2016

The selected seven oligonucleotides primers BION-32, BION-33, BION-35, BION-38, BION-40, BION-46 and BION-58 generated the shared loci, specific loci, unique shared loci to each population and shared loci by the three T. granosa populations in Beolgyo, a Chinese site and Wonsan, respectively. The bandsharing value between individuals' no. 03 and no. 04 was 0.816, which was the highest value identified within the Beolgyo population. The primer BION-35 generated the most loci (a total of 70), with an average of 10.0 in the Wonsan population. On average, seven oligonucleotides primers generated 16.1 specific loci in the Beolgyo population, 22.3 in the Chinese population and 39.3 in the Wonsan population. 126 unique shared loci to each population, with an average of 18 per primer, were observed in the Beolgyo population, 63 loci, with an average of 9 per primer, were observed in the Chinese population, and 49 loci, with an average of 7 per primer, and were observed in the Wonsan population. The oligonucleotides primer BION-32 generated 14 unique loci to each population, which were identifying each population in the Beolgyo population. Interestingly, every primer had not distinguished the shared loci by the three populations, major and/or minor fragments of sizes, which were identical in almost all of the samples. As regards average bandsharing value (BS) results, individuals from Beolgyo population ($0.717{\pm}0.057$) exhibited higher BS values than did those from Wonsan population ($0.552{\pm}0.104$) (P < 0.05). The dendrogram resulted from truthful seven oligonucleotides primers, representing three genetic clusters comprising group I (BEOLGYO 01, 02, 03, 04, 05, 06 and 07), group II (CHINESE 08, 09, 10, 11, 12, 13 and 14) and group III (WONSAN 15, 16, 17, 18, 19, 20 and 21). In three T. granosa populations, the longest genetic distance (0.874) displaying significant molecular difference was also between individual no. 02 within the Beolgyo population and individual no. 12 within the Chinese population. Relatively, individuals of the CHINESE population were fairly closely related to those of the WONSAN population.

• Hip & pelvis
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• 제30권4호
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• pp.254-259
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• 2018

Purpose: Internal fixation using compression hip screws (CHS) and traction tables placing patients in the supine position is a gold standard option for treating intertrochanteric fractures; however, at our institution, we approach this treatment with patients in a lateral decubitus position. Here, the results of 100 consecutive elderly (i.e., ${\geq}45$ years of age) patients who underwent internal fixation with CHS in lateral decubitus position are analyzed. Materials and Methods: Between March 2009 and May 2011, 100 consecutive elderly patients who underwent internal fixation with CHS for femoral intertrochanteric fracture were retrospectively reviewed. Clinical outcomes (i.e., Koval score, Harris hip score [HHS]) and radiographic outcomes (i.e., bone union time, amount of sliding of lag screw, tip-apex distance [TAD]) were evaluated. Results: Clinical assessments revealed that the average postoperative Koval score decreased from 1.4 to 2.6 (range, 0-5; P<0.05); HHS was 85 (range, 72-90); and mean bone union time was 5.0 (range, 2.0-8.2) months. Radiographic assessments revealed that anteroposterior average TAD was 6.95 (range, 1.27-14.63) mm; lateral average TAD was 7.26 (range, 1.20-18.43) mm; total average TAD was 14.21 (range, 2.47-28.66) mm; average lag screw sliding was 4.63 (range, 0-44.81) mm; and average angulation was varus $0.72^{\circ}$(range, $-7.6^{\circ}-12.7^{\circ}$). There were no cases of screw tip migration or nonunion, however, there were four cases of excessive screw sliding and six cases of varus angulation at more than $5^{\circ}$. Conclusion: CHS fixation in lateral decubitus position provides favorable clinical and radiological outcomes. This technique is advisable for regular CHS fixation of intertrochanteric fractures.

• International journal of advanced smart convergence
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• 제12권4호
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• pp.386-394
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• 2023

This study investigated changes in salivary cortisol, lactic acid, and heart rate along the route during walking exercise in a forest environment for the purpose of reducing stress. Walking exercise in a forest environment was conducted on a Hill Type (Distance: 800m, Average slope 25°, Altitude 112m) and Step Type (Distance: 800m, Average slope 25°, Altitude 114m) routes for 10 female college students in their 20s. The subjects were asked to walk at a speed of 60 bpm. The resulting changes in salivary cortisol, lactate, and average heart rate during exercise were compared and analyzed using Repeated Measurement two-way ANOVA, and the maximum heart rate during exercise and average heart rate at rest were compared and analyzed using paired t-test, and the following results were obtained. First, there was no significant difference in salivary cortisol depending on the type and period of the forest, but it tended to gradually decrease. Second, there was a significant difference in lactic acid depending on the type and period, and it was higher in Step Type. Third, there was a significant difference in the average heart rate during exercise, and it was higher in Step Type. Fourth, there was a significant difference in maximum heart rate during exercise, and it was higher in Step Type. Fifth, there was no significant difference in average heart rate during rest. In summary, walking exercise in a forest environment can be effective for stress reduction for female college students in their 20s, but it appears that forest routes should be selected according to physical strength level, and walking exercise in a forest environment for long periods of time is not recommended. For this purpose, it is suggested that it is appropriate to select the Hill Type route.

• 한국항행학회논문지
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• 제12권5호
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• pp.412-419
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• 2008

유전자 알고리즘은 효과적으로 최적의 해를 구하는 기법이나 진화연상산자의 선정에 따라 조기에 국부 최적해에 고착되어 전역 최적해로의 탐색을 어렵게 하는 문제점을 가지고 있다. 본 논문에서는 국부 최적해로 수렴하게 되는 원인을 분석하고, 국부 최적해에서 벗어나 전역 최적해로의 천이가 가능하도록 하는 방법을 제안하였다. 본 논문에서 사용한 방법은 평균 해밍거리에 따라 진화연산자를 가변시키는 방법으로서 국부 최적해에 고착되지 않도록 유전자에 다양성을 부여하여 지속적으로 모집단의 진화 특성을 유지하는 방법이다. 제안된 방법은 시뮬레이션을 통하여 효용성을 입증하였다.