• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.9 no.5
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• pp.427-436
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• 2019

This study investigated the effect of extracorporeal shock wave therapy on the knee angle, MAS, and TUG of the affected side in patients with hemiplegic strokes. This study selected 20 patients who received rehabilitation treatment at a hospital after having been diagnosed with stroke. The control group (n=10) received the general physiotherapy (proprioceptive neuromuscular facilitation), and the experimental group (n=10) applied the extracorporeal shock wave therapy (ESWT) to the injured limb after PNF treatment. This study used an integrated kinematics analyzer (4D-MT, Relive, Korea) to analyze walking, timed up and go test to evaluate the dynamic balance ability of patients, and MAS to evaluate the spasticity. In the study results, knee angle were significantly different in all groups(p<0.05) but there was no significant difference between the groups(p>0.05). In the study results, TUG were significantly different in all groups(p<0.05) but there was no significant difference between the groups(p>0.05). Based on the results of this study, I hope that more detailed research will proceed.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.33 no.3
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• pp.110-121
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• 2021

The importance of tidal flats lost due to industrialization has recently received attention, and attention is being paid to the creation of artificial tidal flats and maintenance of natural tidal flats. However, there is still a lack of understanding about the behavioral characteristics of mud, mud, and sand that form tidal flats. Although research on the movement characteristics of mixed soils such as tidal flats has been conducted through field investigations and hydraulic experiments, interest in developing a numerical model based on these results has not yet reached. In this paper, the purpose of this paper is to establish a mixed soil model that can efficiently manage the low quality of the tidal flats. In constructing a model for reproducing the surface movement of mixed soil, the numerical stability of the reproduction and movement of sand and mud constituting the mixed soil in the numerical model should be considered first, so first, the volume of sand and mud constituting the mixed soil A mixed soil model representing the relationship was proposed based on a topographical diagram representing the geometric structure of the mixed soil. In order to consider the dry bulk density of the mixed soil, it was possible to consider the dry bulk density of the mud by introducing the water content of the mud containing water. In addition, it was confirmed that the mud and sand movement calculation according to the slope collapse of the mixed soil was stably performed through the calculation of the slope collapse of the mixed soil through the numerical analysis model to which the proposed mixed soil model was applied.

• Applied Chemistry for Engineering
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• v.22 no.4
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• pp.376-383
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• 2011

The CMCs of LA and LA3 nonionic surfactants obtained from the reaction between glycidol and lauryl alcohol were found to be $0.97{\times}10^{-3}mol/L$ and $1.02{\times}10^{-3}mol/L$ respectively and the surface tensions for 1 wt% surfactant were 26.99 and 27.48 mN/m respectively. Dynamic surface tension measurements using a maximum bubble pressure tensiometer showed that the adsorption rate of surfactant molecules at the interface between the air and the surfactant solution was found to be relatively fast in both surfactant systems, presumably due to the high mobility of surfactant molecules. The contact angles of LA and LA3 nonionic surfactants were 27.8 and $20.9^{\circ}$ respectively and the dynamic interfacial tension measurement by a spinning drop tensiometer showed that interfacial tensions at equilibrium condition in both systems were almost the same. Also both surfactant systems reached equilibrium in 2~3 min. Both surfactant solutions showed high stability when evaluated by conductometric method and the LA nonionic surfactant system provided the higher foam stability than the LA3 nonionic surfactant system. The phase behavior experiments showed a lower phase or oil in water (O/W) microemulsion in equilibrium with an excess oil phase at all temperatures studied. No three-phase region was observed including a middle-phase microemulsion or a lamellar liquid crystalline phase.

• The Korean Journal of Applied Statistics
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• v.34 no.3
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• pp.309-327
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• 2021

Dynamic treatment regimes (DTRs) are decision-making rules designed to provide personalized treatment to individuals in multi-stage randomized trials. Unlike classical methods, in which all individuals are prescribed the same type of treatment, DTRs prescribe patient-tailored treatments which take into account individual characteristics that may change over time. The Q-learning method, one of regression-based algorithms to figure out optimal treatment rules, becomes more popular as it can be easily implemented. However, the performance of the Q-learning algorithm heavily relies on the correct specification of the Q-function for response, especially in observational studies. In this article, we examine a number of double-robust weighted least-squares estimating methods for Q-learning in high-dimensional settings, where treatment models for propensity score and penalization for sparse estimation are also investigated. We further consider flexible ensemble machine learning methods for the treatment model to achieve double-robustness, so that optimal decision rule can be correctly estimated as long as at least one of the outcome model or treatment model is correct. Extensive simulation studies show that the proposed methods work well with practical sample sizes. The practical utility of the proposed methods is proven with real data example.

• Korean Chemical Engineering Research
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• v.60 no.2
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• pp.282-288
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• 2022

Facial masks have become indispensable in daily life to prevent infection and spread through respiratory droplets in the era of the corona pandemic. To understand how effective two different types of masks (i.e., KF-94 mask and dental mask) are in blocking respiratory droplets, i) we preferentially analyze wettability characteristics (e.g., contact angle and contact angle hysteresis) of filters consisting of each mask, and ii) subsequently observe the dynamic behaviors of microdroplets impacting at high velocities on the filter surfaces. Different wetting properties (i.e., hydrophobicity and hydrophilicity) are found to exhibit depending on the constituent materials and pore sizes of each filter. In addition, the pneumatic conditions for stably and uniformly dispensing microdroplets with a certain volume and impacting behaviors associated with the impacting velocity and filter type change are systematically explored. Three distinctive dynamics (i.e., no penetration, capture, and penetration) after droplet impacting are observed depending on the type of filter constituting the masks and droplet impact velocity. The present experimental results not only provide very useful information in designing of face masks for prevention of transmission of infectious respiratory diseases, but also are helpful for academic researches on droplet impacts on various porous surfaces.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.1
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• pp.59-70
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• 2022

In this paper, we proposed an active fault tolerant control (AFTC) method for the position control of a quadrotor with complete loss of effectiveness of one motor. We obtained the dynamics of a quadrotor using Lagrangian equation without small angle assumption. For detecting the fault on a motor, we designed a fault detection module, which consists of the fault detection and diagnosis (FDD) module and the fault detection and isolation (FDI) module. For the FDD module, we designed a nonlinear observer that observes the states of a quadrotor based on the obtained dynamics. Using the observed states of a quadrotor, we designed residual signals and set the appropriate threshold values of residual signals to detect the fault. Also, we designed an FDI module to identify the fault location using the designed additional conditions. To make a quadrotor track the desired path after detecting the fault of a motor, we designed a fault tolerant controller based on the multiple sliding surface control (MSSC) technique. Finally, through simulations, we verified the effectiveness of the proposed AFTC method for a quadrotor with complete loss of effectiveness of one motor.

• Korean Chemical Engineering Research
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• v.60 no.2
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• pp.300-307
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• 2022

Time-resolved serial femtosecond crystallography (TR-SFX) is a powerful technique for determining temporal variations in the structural properties of biomacromolecules on ultra-short time scales without causing structure damage by employing femtosecond X-ray laser pulses generated by an X-ray free electron laser (XFEL). The mixing rate of reactants and biomolecule samples, as well as the hit rate between crystal samples and x-ray pulses, are critical factors determining TR-SFX performance, such as accurate image acquisition and efficient sample consumption. We here develop two distinct sample delivery systems that enable ultra-fast mixing and on-demand droplet injecting via pneumatic application with a square pulse signal. The first strategy relies on inertial mixing, which is caused by the high-speed collision and subsequent coalescence of droplets ejected through a double nozzle, while the second relies on on-demand pneumatic jetting embedded with a 3D-printed micromixer. First, the colliding behaviors of the droplets ejected through the double nozzle, as well as the inertial mixing within the coalesced droplets, are investigated experimentally and numerically. The mixing performance of the pneumatic jetting system with an integrated micromixer is then evaluated by using similar approaches. The sample delivery system devised in this work is very valuable for three-dimensional biomolecular structure analysis, which is critical for elucidating the mechanisms by which certain proteins cause disease, as well as searching for antibody drugs and new drug candidates.

• Journal of the Korean Wood Science and Technology
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• v.32 no.2
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• pp.40-49
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• 2004

Phyllostachys pubescens planted in the Nambu Forest Experiment station in Jinju city of Gyongnam province was used, to investigate the physical and mechanical property of bamboo in this study. The ages of the P. pubescens were 1, 2 and 3 years, respectively. This experiment was carried out in August and January. The P. pubescens were divided into upper, middle and lower parts according to the growing points. The physical and mechanical properties of the P. pubescens were investigated before and after treatment of hot water and microwave irradiation. 1. The upper part of the P. pubescens indicated the highest static MOE according to the growing points. The range of the static MOE was from 70,000 to 110,000kgf/cm². 2. When P. pubescens were treated with hot water of 95℃, the ratio of softening was about 10~30%. 3. As microwave irradiation time was increased, the MOE values was decreased in both green and water-saturated bamboos. For the irradiation time of 20 and 30 seconds, the static MOE of P. pubescens was decreased up to about 50% comparing with non-treated.

• The Journal of the Korea Contents Association
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• v.22 no.4
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• pp.1-12
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• 2022

Since the early 20th century, along with the interest and development of alternative psychotherapy, the field of art therapy has also been developed and expanded. In particular, the recent development of technology and the untact era brought about by the COVID-19 Pandemic is accelerating the development of new digital art therapy contents. Among them, the hot interest in virtual reality is raising expectations and questions about the effectiveness of psychotherapy given by new media beyond traditional art therapy. In this study, the characteristics of VRAT (Virtual Reality Art Therapy) content therapeutic factors were investigated through qualitative literature analysis based on the conceptual framework and therapeutic components of ETC (Expressive Therapies Continumm), an integrated art therapy theory. As a result of the study, VRAT contents showed mostly therapeutic factors in the left hemisphere that triggered the user's dynamic, perceptual, and cognitive factors, and the therapeutic factors in the right hemisphere, which focused on sensory, emotional, and symbolic factors, were relatively few. The reason seems to be due to the nature of the experimental stage, the absence of active intervention by the therapist and long-term session composition, and the fear, clumsiness, and unfamiliarity of users about VRAT in addition to the characteristics and technical limitations of the VRAT medium. The limitations of the study include the small number of documents to be analyzed and the insufficient form of current VRAT to be called art therapy. It is expected that the characteristics of the therapeutic factors of VRAT content media and environment derived as a result of this study will be usefully used for the appropriate development of VRAT content in the future.

• KIPS Transactions on Computer and Communication Systems
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• v.11 no.10
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• pp.363-372
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• 2022

Since the recent COVID-19 Pandemic, the ransomware fandom has intensified along with the expansion of remote work. Currently, anti-virus vaccine companies are trying to respond to ransomware, but traditional file signature-based static analysis can be neutralized in the face of diversification, obfuscation, variants, or the emergence of new ransomware. Various studies are being conducted for such ransomware detection, and detection studies using signature-based static analysis and behavior-based dynamic analysis can be seen as the main research type at present. In this paper, the frequency of ".text Section" Opcode and the Native API used in practice was extracted, and the association between feature information selected using K-means Clustering algorithm, Cosine Similarity, and Pearson correlation coefficient was analyzed. In addition, Through experiments to classify and detect worms among other malware types and Cerber-type ransomware, it was verified that the selected feature information was specialized in detecting specific ransomware (Cerber). As a result of combining the finally selected feature information through the above verification and applying it to machine learning and performing hyper parameter optimization, the detection rate was up to 93.3%.