• Journal of The Korean Society of Integrative Medicine
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• v.10 no.3
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• pp.13-25
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• 2022

Purpose : The purpose of this study was to investigate the effects of combined cervical stabilization exercise (CSE) and stretching exercise (SE) on office workers with forward head posture (FHP). Methods : A total of 32 office workers with forward head posture were randomly assigned to experimental (n=16) and control (n=16) groups. The experimental group underwent combined CSE and SE, and the control group underwent cervical self-myofascial release and SE. Both groups performed exercises for 40 min per day, thrice per week for a total of 6 weeks. Craniovertebral angle (CVA), respiration, disability, and joint range of motion (ROM) before and 6 weeks after intervention were measured and compared. Results : There was no significant between-group difference in the general characteristics (p>.05). The intra-group comparison showed significant differences in the visual analog scale (VAS) and neck disability index (NDI) of both groups post-intervention (p<.05). CVA and forced expiratory volume in 1 seconds (FEV₁) were significantly improved post-intervention in the experimental group only (p<.05). In the experimental group, all ROM variables were significantly improved post-intervention. In contrast, in the control group, all ROM variables improved significantly post-intervention, except for extension (p<.05). The inter-group comparison showed significant differences in NDI, left lateral flexion, right lateral flexion, and left rotation between the two groups (p<.05). Conclusion : The combination of CSE and SE, which stabilizes the cervical spine, had positive effects on cranial rotation angle, respiration, disability, and joint ROM in office workers with forward head posture. Therefore, the combination of the two exercises may be an effective option to reduce symptoms and prevent postural problems in office workers with FHP.

• Journal of Korean Physical Therapy Science
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• v.30 no.3
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• pp.59-71
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• 2023

Background: This study was to investigate the effects of coordinative locomotor training(CLT) using elastic bands on pain, dynamic balance, muscle strength, and muscle activity of female college students with patellofemoral pain syndrome(PFPS). Design: Randomized Controlled Trial Methods: Twenty-six female college students with PFPS were assigned randomly to an experimental(n=13) or control(n=13) group. The experimental group performed CLT using an elastic band. The control group performed squat exercises to strengthen muscle strength. The 30-minute inter- vention was applied a total of twelve times, three times a week for four weeks. All subjects measured the pain, the muscle strength, the dynamic balance, and the muscle activity(VL/VM ratio) before and after intervention. A paired t-test was used for the determination of differences before and after treatment, and an independent t-test was used for the determination of differences between treatment groups. Results: As a result of comparison within groups, the experimental group showed significant differences in pain, muscle strength, dynamic balance, and VL/VM ratio after the experiment(p<0.05), and the control group showed significant differences in pain, muscle strength, and dynamic balance after the experiment(p<0.05). In comparison between the two groups, the experimental group showed more significant differences in pain, dynamic balance, and VL/VM ratio than the control group(p<0.05), and the control group showed more significant differences in muscle strength than the experimental group(p<0.05). Conclusion: Based on these results, CLT using elastic bands effectively improved the pain, muscle strength, dynamic balance, and VL/VM ratio of female college students with PFPS.

• The Journal of the Acoustical Society of Korea
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• v.27 no.3
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• pp.119-128
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• 2008

This paper analyzes the relationship between two representative statistical methods for bandwidth extension (BWE): Gaussian Mixture Model (GMM) and Hidden Markov Model (HMM) ones, and compares their performances. The HMM method is a memory-based system which was developed to take advantage of the inter-frame dependency of speech signals. Therefore, it could be expected to estimate better the transitional information of the original spectra from frame to frame. To verify it, a dynamic measure that is an approximation of the 1st-order derivative of spectral function over time was introduced in addition to a static measure. The comparison result shows that the two methods are similar in the static measure, while, in the dynamic measure, the HMM method outperforms explicitly the GMM one. Moreover, this difference increases in proportion to the number of states of HMM model. This indicates that the HMM method would be more appropriate at least for the 'blind BWE' problem. On the other hand, nevertheless, the GMM method could be treated as a preferable alternative of the HMM one in some applications where the static performance and algorithm complexity are critical.

• Journal of Marine Life Science
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• v.9 no.1
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• pp.9-21
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• 2024

Paralytic shellfish poisoning (PSP) including Saxitoxin (STX) is caused by harmful algae, and poisoning occurs when the contaminated seafood is consumed. The mouse bioassay (MBA), a standard test method for detecting PSP, is being sanctioned in many countries due to its low detection limit and the animal concerns. An alternative to the MBA is the Neuro-2a cell-based assay. This study aimed to establish various test conditions for Neuro-2a assay, including cell density, culture conditions, and STX treatment conditions, to suit the domestic laboratory environment. As a result, the initial cell density was set to 40,000 cells/well and the incubation time to 24 hours. Additionally, the concentration of Ouabain and Veratridine (O/V) was set to 500/50 μM, at which most cells died. In this study, we identified eight concentrations of STX, ranging from 368 to 47,056 fg/μl, which produced an S-shaped dose-response curve when treated with O/V. Through inter-laboratory variability comparison of the Neuro-2a assay, we established five Quality Control Criteria to verify the appropriateness of the experiments and six Data Criteria (Top and Bottom OD, EC₅₀, EC₂₀, Hill slop, and R² of graph) to determine the reliability of the experimental data. The Neuro-2a assay conducted under the established conditions showed an EC₅₀ value of approximately 1,800~3,500 fg/μl. The intra- & inter-lab variability comparison results showed that the coefficients of variation (CVs) for the Quality Control and Data values ranged from 1.98% to 29.15%, confirming the reproducibility of the experiments. This study presented Quality Control Criteria and Data Criteria to assess the appropriateness of the experiments and confirmed the excellent repeatability and reproducibility of the Neuro-2a assay. To apply the Neuro-2a assay as an alternative method for detecting PSP in domestic seafood, it is essential to establish a toxin extraction method from seafood and toxin quantification methods, and perform correlation analysis with MBA and instrumental analysis methods.

• Journal of Korean Port Research
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• v.14 no.3
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• pp.279-290
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• 2000

The purpose of this study is to suggest the analytical framework for a spatial structure of a tourism destination master plan by the two types of the tourism development models: Tourist attraction System Model and Tourism Destination Region Design Model. The resort development plan is introduced as a planning tool for regenerating the eastern Pusan regions, but the economic and environmental impacts and the sociocultural dilemma accompanied by the development should be fully considered before launching the business. The development plan announced currently is traced and examined in comparison with the upper-leveled and related plans. The Tourist Attraction System Model based on the systems theory is applied to the designated regions. The Tourism Destination Region Design Model then is applied for analyzing the components of each region on the master plan. The results of the findings suggest that the tourism destination plan is basically different from a general master plan on the physical comprehensive plan, the destination is recognized as a subsystem of the whole tourism system, and thus tourism destination plan is considered as a spatial arrangement of tourism facilities and the inter- and intra-circulation.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38C no.3
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• pp.288-295
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• 2013

In this paper, we compare the existing channel estimation technique for 4S (Ship to Ship, Ship to Shore) maritime communications under AWGN channel model, Rician fading channel model, and Rayleigh fading channel model respectively. In general, the received signal is corrupted by multipath and ISI (Inter Symbol Interference). The estimation of a time-varying multipath fading channel is a difficult task for the receiver. Its performance can be improved if an appropriate channel estimation filter is used. The simulation is performed in MATLAB. In this simulation, we use the popular estimation algorithms, LMS (Least Mean Square) and RLS (Recursive Least-Squares) are compared with respect to AWGN, Rician and Rayleigh channels.

• Atmosphere
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• v.23 no.2
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• pp.123-130
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• 2013

Despite the extensive investigations to understand the difference between ground-based and space-borne measurements, there still exist differences in total ozone (TO) measured at those two different platforms. Comparisons were carried out for the first time between TO data obtaiend from the ground based Dobson and Brewer spectrophotometers, and the Ozone Monitoring Instrument (OMI) on board EOS-Aura satellite in a megacity site in Northeast Asia. The TO values retrieved by the OMI-DOAS (Differential optical absorption spectroscopy) algorithm tend to be lower than those measured by the ground based sensors in spring and summer as well as the low solar zenith angle condition. We found that such underestimation of the OMI-DOAS TO is caused by tropospheric ozone underestimated by the OMI-DOAS algorithm when tropospheric ozone are significantly enhanced.

• Journal of Institute of Control, Robotics and Systems
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• v.21 no.6
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• pp.589-594
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• 2015

In this paper, we described the Cramer-Rao Lower Bound (CLRB) performances of Time Difference of Arrival (TDOA) and Frequency Difference of Arrival (FDOA) methods when there are multiple emitters. The TDOA and FDOA values between two receivers can be simultaneously estimated by using the so-called Complex Ambiguity Function (CAF). In the case of multiple emitters, there exist Inter Symbol Interferences (ISIs) in the measurement data. Therefore, it is required to reduce the effect of ISI and provide a performance evaluation method of TDOA and FDOA estimations. In order to eliminate the ISIs, using of a filter bank before calculating CAF is proposed when the carrier frequencies of the emitters are different to one another. Angle of Arrival (AOA) or Received Signal Strength (RSS) methods before calculating CAF were proposed to reduce the ISIs when the carrier frequencies are the same. In order to evaluate the CRLB of TDOA and FDOA estimations, we employed the conditional probability distribution method and described the numerical comparison results.

• The Journal of the Acoustical Society of Korea
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• v.20 no.3E
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• pp.3-9
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• 2001

This study aims to describe a prosodic pattern on the Korean subjective particles with respect to their discourse function. 4 kinds of Korean subjective particles were mainly investigated with reference to sentential location, grammatical relations that precede or follow the word including subjective particles, and prosodic phrasing. F0 and energy were gradually diminished as the particles moved down to the sentential final position. 'Ga'particle, which has been potentially regarded as having a grammatical focusing function, looks like to show relatively higher F0 in sentential medial in discourse. At sentential medial position, when the words including 'ga, eun, and neun'particles were preceded by adverbials, the acoustic variables of particles tended to be diminished by some ratio in comparison with the mean value. The duration of particles might vary with respect to style variation and especially that it tended to diminish from 150 basic, 50 separate, and finally 50 discourse successively. And there's some specific phenomenon that prosodic phrasing itself was relatively easily taken place after 'eun' and 'neun' particles. Finally, I tried to catch the prosodic characteristics (which would be established as acoustic features) of inter-word position at which specific subjective particles were intervened. These acoustic features can be made up of the duration and F0 fluctuation activated in the successive 3 syllables in which word (or prosodic) boundary was located.

• Steel and Composite Structures
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• v.20 no.4
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• pp.777-799
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• 2016

One of the major components for performance based seismic design is accurate estimation of critical seismic demand parameters. While nonlinear seismic analysis is the most appropriate analysis method for estimation of seismic demand parameters, this method is very time consuming and complex. Single mode pushover analysis method, N2 method and multi-mode pushover analysis method, modal pushover analysis (MPA) are two nonlinear static methods that have recently been used for seismic performance evaluation of few lateral load-resisting systems. This paper further investigates the applicability of N2 and MPA methods for estimating the seismic demands of ductile unstiffened steel plate shear walls (SPSWs). Three different unstiffened SPSWs (4-, 8-, and 15-storey) designed according to capacity design approach were analysed under artificial and real ground motions for Vancouver. A comparison of seismic response quantities such as, height-wise distribution of floor displacements, storey drifts estimated using N2 and MPA methods with more accurate nonlinear seismic analysis indicates that both N2 and MPA procedures can reasonably estimates the peak top displacements for low-rise SPSW buildings. In addition, MPA procedure provides better predictions of inter-storey drifts for taller SPSW. The MPA procedure has been extended to provide better estimate of base shear of SPSW.