• Fisheries and Aquatic Sciences
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• v.21 no.11
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• pp.31.1-31.7
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• 2018

Three economic marine algae that have been used as food and carrageenan sources were collected from Korea during a survey of marine algal flora. They share the generic features of Hypnea, and three major clades supported by the sectional features were confirmed in a phylogenetic tree based on rbcL sequences. The first species, which belongs to a species group corresponding to the sect. Spinuligerae, nests in the same clade with Hypnea yamadae in a genetic distance of 0%. It is morphologically characterized by an entangled base, subcompressed or subterete to terete axes, somewhat percurrent main axis, irregularly alternately branching with wide angle, and rarely hooked spinous branchlets. The second one is also referred to the sect. Spinuligerae and formed the same clade as Hypnea cenomyce. The genetic distance between both sequences was calculated as 0.0-0.1%, which is considered to be intraspecific. This species is distinct by somewhat entangled thallus at the basal part, percurrent axis, short spine-like branchlets densely covering the axis, and medullary lenticular thickenings. The third alga, which forms a species group corresponding to the sect. Pulvinatae, nests in the same clade as Hypnea nidulans (no intraspecific divergence). It shows occasionally epiphytic habitat rather than epilithic habitat of low mat-forming growth and percurrent erect main axes with dense lateral branchlets. Based on these morphological and molecular data, the three Korean species are identified as H. yamadae, H. cenomyce, and H. nidulans. This is the first record of the Hypnea species in Korea.

• The Journal of Asian Finance, Economics and Business
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• v.8 no.2
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• pp.151-164
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• 2021

The paper identifies the enablers (drivers) and inhibitors (barriers) influencing e-customs implementation in Vietnam (known as a developing country with a lower technological environment) along with determining the impact of e-customs on firm performance. The survey was conducted with the representatives (managers) of firms in five cities and provinces dominating Vietnam's international trade. The data was analyzed using structural equation modeling (SEM). The findings show two significant drivers (enablers) - relative advantages and national culture, while compatibility and ease of use are the barriers. Previous studies showed that cultural dimensions related to 'uncertainty acceptance' and 'individualism' encourage innovation; however, this paper demonstrates that 'uncertainty avoidance' and 'collectivism' promote e-customs deployment in Vietnam. Previously, Vietnamese culture was known for scoring high on cultural dimensions related to 'power distance' and 'short-term orientation'. However, today, as an emerging country, Vietnamese has switched to 'low distance' and 'long-term orientation', especially in terms of e-customs innovation. Additionally, the paper also emphasized that e-customs implementation had a positive influence on firm performance in Vietnam. Based on the results of the paper, policy-makers can devise essential solutions to enhance e-customs implementation as well as managers of firms can set-up strategies to adapt to the modernized environment.

• Journal of the Korean Vacuum Society
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• v.6 no.S1
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• pp.127-132
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• 1997

Microstructure of the Fe-Ti system by ion beam mixing of multilayers at 300 K and 77 K has been studied in a wide composition range. The ion bombardment was carried out using $Ar^+$ ions at 80 keV. Using grazing angle x-ray diffraction we find that the lattice parameters of these bcc solid solutions are very close to that of $\alpha$-Fe. Extended x-ray absorption fine-structure spectroscopy have been performed to investgate the short-range order in the ion-beam-mixed state. The structure parameters, such as the interatomic distance and the coordination number are estmated from the Fe K-edge Fourier filtered EXAFS spectra. The interatomic distance is independent of the alloy concentration and it is almost constant. The study of x-ray absorption near-edge structure gives information on the individual $\rho$components of the partial densityof states of the conduction band of the Fe and Ti We also find that a charge transfer from Ti to Fe atoms takes place.

• Journal of the Korea Institute of Military Science and Technology
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• v.26 no.1
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• pp.22-30
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• 2023

When tracking small UAVs and drone targets in cloud clutter environments, MWIR sensors are often unable to track targets continuously. To overcome this problem, the SWIR sensor is mounted on the same gimbal. Target tracking uses sensor information fusion or selectively applies information from each sensor. In this case, parallax correction using the target distance is often used. However, it is difficult to apply the existing method to small UAVs and drone targets because the laser rangefinder's beam divergence angle is small, making it difficult to measure the distance. We propose a tracking method which needs not parallax correction of sensors. In the method, images from MWIR and SWIR sensors are captured simultaneously and a tracking error for gimbal driving is chosen by effectiveness measure. In order to prove the method, tracking performance was demonstrated for UAVs and drone targets in the real sky background using MWIR and SWIR image sensors.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.6
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• pp.243-249
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• 2010

In this thesis, in order to a equivalent circuit-analytical study for a symmetric double gate type MOSFET, we slove analytically the 2D Poisson's equation in a a silicon body. To solve the threshold voltage in a symmetric double gate type MOSFET from the derived expression for the surface potential which the two-dimensional potential distribution of a symmetric double gate type MOSFET is assumed approximately. This thesis can use short and long channel in a silicon body we introduce a new the threshold voltage model in a symmetric double gate type MOSFET and measure it the distance about the range of channel length up to 0.1 [${\mu}m$].

• Journal of Korean Academy of Nursing
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• v.33 no.5
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• pp.570-579
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• 2003

Purpose: The purpose of this study is to exam the effects of a short-term pulmonary program on lung function, exercise tolerance, and quality of life in chronic lung patients. Method: Randomized controlled pre-post test design was used. The outcome measures were forced expiratory volume in one second (FEV1, % predicted), 6 min walking distance (6MWD), Borg score after 6MWD, and Chronic Respiratory Disease Questionnaire (CRDQ). Experimental group performed the 4-week home-based pulmonary rehabilitation program composed of inspiratory muscle training, upper and lower extremity exercise, relaxation, and telephone visit. Patients in control group were only given education about self-management strategies. Thirty four patients with moderate-to-severe respiratory impairment were recruited, and 28 patients (19 in experiments, 15 in control) completed the study. Result: Significant improvements in lung function, exercise tolerance, and health related quality of life were found only in the experiment group. Conclusion: This study yielded evidence for the potential and beneficial effects of home-based pulmonary rehabilitation program in patients with moderate to severe chronic lung disease. The program could be adequately utilized for improvement of health related quality of life in chronic lung patients.

• Journal of The Korean Society of Agricultural Engineers
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• v.48 no.6
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• pp.69-77
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• 2006

In this study, the large scaled model test improved by sand drain was carried out to clarify the internal behavior of the three-dimensional consolidation under different secondary consolidation periods. From the results of model test, the void ratio in the undrained side was lager than in the drained side. In addition, the unconfined compressive strength in the long-term consolidated specimen was larger than that in the short-term consolidated one. It was also found that the unconfined compressive strength was larger in the drained side than in the undrained side. These reasons are considered to be due to the large effective stress by quick pore water pressure dissipation by the short drainage distance in the drained side. Furthermore, in order to investigate the three-dimensional consolidation behavior of clay ground improved by the vertical drain method, the numerical analysis obtained from the three-dimensional elasto-viscous consolidation theory proposed by author (2006) were compared with the test results. It was found that during the three-dimensional consolidation process not only vertical displacement but also radial displacement occurs inside the specimen.

• Journal of Advanced Navigation Technology
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• v.4 no.2
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• pp.143-151
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• 2000

In this paper, short range IVC(Inter-Vehicle Communication) channel is modeled in three kinds considering rain attenuation and oxygen absorption. And the performance of DS/CDMA communication system in one path Rician model suitable for platton driving which is the final goal of AVHS(Advanced Vehicle & Highway System) is analyzed. Also, the reflection coefficients in 60 GHz is calculated. For the performance improvement both BCH channel coding and MRC diversity reception technique are adopted. The BER performance is evaluated as a function of packet length, Rician depth and the distance between vehicles.

• Journal of Korean Neurosurgical Society
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• v.40 no.5
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• pp.346-350
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• 2006

Objective : The ability to induce segmental lordosis has been reported to be marginal with transforaminal lumbar interbody fusion[TLIF]. Therefore, we analyzed the short-term radiological outcomes of TLIF using $8^{\circ}$ wedged cages for isthmic spondylolisthesis. Methods : Twenty-seven patients with isthmic spondylolisthesis who underwent single level TLIF with pedicle screw fixation[PSF] using $8^{\circ}$ wedged cages were retrospectively evaluated. Changes in disc height, degree of anterolisthesis, segmental lumbar lordosis, whole lumbar lordosis and L1 axis S1 distance were evaluated using standing lateral radiographs before surgery, at 6 weeks follow-up and at the final follow-up. Results : The mean age of the patients was 49.9 years [range, 38 to 64 years]. The affected levels were L4-5 in 17 cases and L5-S1 in 10. There were 18 cases of Grade I isthmic spondylolisthesis and 9 cases of Grade II. At a mean follow-up duration of 9.9 months [range, 6 to 18 months], the disc height [p< 0.001] was significantly increased, and the degree of anterolisthesis was significantly reduced [p< 0.001]. Regarding the sagittal balance, the segmental lumbar lordosis was significantly increased [p=0.01], but other parameters were not significantly changed after surgery. Conclusion : TLIF with PSF using $8^{\circ}$ wedged cages significantly increased the segmental lumbar lordosis.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.1
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• pp.166-171
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• 2012

In this paper, short-range underwater wireless communication technique using visible LEDs is proposed. As an alternative to conventional acoustic system, visible LED communications show high quality and high speed data transmission characteristics. We design a frequency modulation-based optical wireless audio transmission system. The CD4046B phase-locked loop device is applied to implement the frequency modulation and demodulation. With a transmission modulation of 100 kHz, audio signal has successfully received at a transmission distance of 30 cm.