• Journal of the Korean Society of Propulsion Engineers
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• v.24 no.6
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• pp.78-84
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• 2020

The performance of pintle thruster is analyzed by using the pintle thruster performance analysis model which integrating the element models introduced in Part I. To verify the performance analysis, the results of the developed program are compared with the experimental data of kerosene/hydrogen peroxide liquid pintle thrusters. Based on the results, the characteristics of the pintle thruster are analyzed. The sensitivity analysis is performed to investigate the effect of thruster shape and operation parameters on performance characteristics using both OAT and scatter plot methods. The four performance parameters such as droplet diameter, film flow rate, O/F ratio, and nozzle throat diameter are evaluated to investigate their effects on characteristic speed, combustor pressure, and specific thrust.

• CELLMED
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• v.11 no.1
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• pp.6.1-6.7
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• 2021

In situ gelling devices, as they enter the body, are dosage forms in the shape of the sol but turn into gel types under physiological circumstances. Transition from sol to gel is contingent on one or a mixture of diverse stimuli, such as transition of pH control of temperature, irradiation by UV, by the occurrence of certain ions or molecules. Such characteristic features may be commonly employed in drug delivery systems for the production of bioactive molecules for continuous delivery vehicles. The technique of in situ gelling has been shown to be impactful in enhancing the potency of local or systemic drugs supplied by non-parenteral pathways, increasing their period of residence at the absorption site. Formulation efficacy is further improved with the use of mucoadhesive agents or the use of polymers with both in situ gelling properties and the ability to bind with the mucosa/mucus. The most popular and common approach in recent years has provided by the use of polymers with different in situ gelation mechanisms for synergistic action between polymers in the same formulation. In situ gelling medicine systems in recent decades have received considerable interest. Until administration, it is in a sol-zone and is able to form gels in response to various endogenous factors, for e.g elevated temperature, pH changes and ions. Such systems can be used in various ways for local or systemic supply of drugs and successfully also as vehicles for drug-induced nano- and micro-particles. In this review we will discuss about various aspects about use of these in situ gels as novel drug delivery systems.

• Korean Journal of Environmental Agriculture
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• v.39 no.4
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• pp.281-288
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• 2020

BACKGROUND: Generally, ammonia occurs from agricultural waste disposal. Ammonia is known as a harmful substance to the human body and has a bad influence such as eutrophication on the ecosystem. It is possible to remove the ammonia by ammonia adsorption method using natural zeolite, without external influence. However, due to the natural zeolite shape, it is hard to reuse. METHODS AND RESULTS: Electrospinning method can produce fiber with constant diameter. Moreover, electrospinning method has no limitation for selecting the material to make the fiber, and thus, it is valuable to reform the surface of adsorbent. In this study, reusable membrane was made by electrospinning method. The highest removal efficiency was shown from the membrane with 20% of zeolite included, and it has been verified that it is possible to reuse the membrane through chemical treatment. The highest ammonia removal efficiency was about 92.4%. CONCLUSION: In this study, ammonia adsorption characteristics of zeolite fibers were studied. Electrospinning method can produce zeolite fiber with even distribution. Ammonia can be removed efficiently from ion exchange ability of the natural zeolite. The result of adsorption isotherm indicated that both Freundlich model and Langmuir model provided the best fit for equilibrium data. And study on desorption has demonstrated that the ion exchange from zeolite was reversible when 0.01 M NaCl and KCl solution were used.

• Structural Engineering and Mechanics
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• v.78 no.5
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• pp.599-610
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• 2021

Early detection of small concrete crack or reinforcement corrosion is necessary for Structural Health Monitoring (SHM). Global vibration based methods are advantageous over local methods because of simple equipment installation and cost efficiency. Among vibration based techniques, FRF based methods are preferred over modal based methods. In this study, a new coupled method using frequency response function (FRF) and proper orthogonal modes (POM) is proposed by using the dynamic characteristic of a damaged beam. For the numerical simulation, wave finite element (WFE), coupled with traditional finite element (FE) method is used for effectively incorporating the damage related information and faster computation. As reported in literature, hybrid combination of wave function based wave finite element method and shape function based finite element method can addresses the mid frequency modelling difficulty as it utilises the advantages of both the methods. It also reduces the dynamic matrix dimension. The algorithms are implemented on a three-dimensional reinforced concrete beam. Damage is modelled and studied for two scenarios, i.e., crack in concrete and rebar corrosion. Single and multiple damage locations with different damage length are also considered. The proposed methodology is found to be very sensitive to both single- and multiple- damage while being computationally efficient at the same time. It is observed that the detection of damage due to corrosion is more challenging than that of concrete crack. The similarity index obtained from the damage parameters shows that it can be a very effective indicator for appropriately indicating initiation of damage in concrete structure in the form of spread corrosion or invisible crack.

• Journal of Korean Medical classics
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• v.34 no.1
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• pp.135-148
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• 2021

Objectives : The purpose of this paper is to study the correlation between cheekbone and life span prediction. Methods : The 『Huangdineijing』 was searched for verses that include terms that refer to the zygoma such as '顴骨', '䪼', '頄', '目下', '墻'. Terms such as '大骨' that are directly related to life span were searched as well, of which the results were analyzed. The relationship between bone shape and life span, the characteristic of facial bone diagnosis, the relationship between zygoma diagnosis and life span, and zygoma related contents in physiognomy texts such as the 『Mayixiangfa』 were examined. Results & Conclusions : Dagu[大骨, big bone] refers to bones in major joints that reflect the condition of Essence Qi, which is why the diagnosis of Dagu is key to determining one's life span. The zygoma is the big bone of the face, and a bad complexion in this area reflects pathogenic heat penetration into the Kidney, which is the foundation of Yin. As Kidney water as Yin Essence is directly connected to life, complexion change in the zygomatic area is highly relevant to life span. Moreover, as one of the main bones where the Kidney Essence is concentrated, the zygoma is the last to stand when the body is deteriorating, as it is the manifestation of heightened bone qi that is rooted in Yin Essence, thus an important site that provides clues to determine one's life span.

• The Research Journal of the Costume Culture
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• v.28 no.6
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• pp.858-874
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• 2020

This study attempts to analyze the social and cultural meanings of the ethnic groups to which different types of shamans belong in Siberia from the appearance characteristics in terms of clothing through Roland Barthes's semiotic theory. The research method here is to analyze three types of shaman costume classified by Holmberg, which are bird-type, deer-type, and bear-type, through theoretical research and to investigate the analysis process of Roland Barthes's semiotics theory. Roland Barthes's approach to semiotics presents an analysis model that can explore the sociocultural meaning of the Siberian shaman costume. The research results are as follows. In the first type, to be closer to the god of the upperworld, shamans transform themselves into birds by decorating their costumes with the characteristic elements of birds such as feathers and wings. In the second type, the shamans' costumes are made of deerskin, and the headdress is shown in the shape of antlers to make it easier to receive messages from the upperworld and run fast in the underworld. In the third type, the shaman's costume is made of bearskin, the head is covered with bearskin, and the body is decorated with bear pendants. Through the power of the bear, the shaman is sent to the underworld to defeat evil gods and remove diseases. Shamans can show their particularity of being a demigod and non-binary gender through clothing. They use this to reflect their authority as a medium of communication between man and god.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.1
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• pp.30-40
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• 2022

Electrocardiogram (ECG) signal's shape and characteristic varies through each individual, so it is difficult to classify with one neural network. It is difficult to classify the given data directly, but if corresponding normal beat is given, it is relatively easy and accurate to classify the beat by comparing two beats. In this study, we classify the ECG signal by generating the reference normal beat through the template cluster, and combining with the input ECG signal. It is possible to detect abnormal beats of various individual's records with one neural network by learning and classifying with the imaged ECG beats which are combined with corresponding reference normal beat. Especially, various neural networks, such as GoogLeNet, ResNet, and DarkNet, showed excellent performance when using the comparative learning. Also, we can confirmed that GoogLeNet has 99.72% sensitivity, which is the highest performance of the three neural networks.

• Journal of Korea Water Resources Association
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• v.55 no.1
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• pp.59-70
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• 2022

Water distribution systems (WDSs) are a representative infrastructure injecting chlorine to disinfect the pathogenic microorganisms and supplying water from sources to consumers. Also, WDSs prescribe to maintain the usual standard (0.1-4.0 mg/L) of residual chlorine. However, the user's usage pattern, water age, network shape, and type affect the hydraulic features (i.e. nodal pressure, pipe velocity) and water quality features (i.e., the residual chlorine concentration). Therefore, this study developed an optimization approach for optimizing WDSs considering water quality-hydraulic factors using Multi-objective Harmony Search (MOHS). The design cost and the system resilience were applied as the design objective functions, and the nodal pressure and the concentration of residual chlorine are used as constraints. The derived optimal designs through this approach were analyzed according to network characteristics such as the network shapes and type. These optimal designs can meet the safety of economic and water quality aspects to increase user acceptance.

• Journal of the Korea Convergence Society
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• v.12 no.11
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• pp.291-299
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• 2021

Recently, due to environmental problems caused by densification and high rise of urban areas, interests in air flow is increasing and appropriate shape and layout design of buildings is required. Therefore, in this study, we intend to propose an experimental method that can observe the air flow around a building using thermochromic pigment. Thermochromic pigments have limitations in observing precise temperature changes due to the characteristic that the color changes only with respect to a specific temperature, but they have the advantages of easy configuration of experimental equipment and short time required for experiments. In this study, the air flow tendencies around a building was examined by performing CFD analysis for a simple model and then compared with the thermochromic experiment results in order to review the usefulness of the proposed experimental method. As a result of the experiment, it was possible to observe the formation of separated flow and vortex region generated by buildings using the charateristics of thermochromic pigment and it was confirmed that the proposed method can be useful for buildings design and urban city planning.

• Journal of Fashion Business
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• v.26 no.5
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• pp.36-48
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• 2022

This study aims to analyze the patterns made with knitted jacquard and intarsia techniques to provide essential data to help plan different knitwear designs using the techniques and patterns. Based on approximately 3,000 jacquard and intarsia knitwear published in the four significant womenswear collections over the past decade, eight main pattern types were classified, and each characteristic was analyzed. Firstly, it is a logo and symbol type pattern that appears mainly as a means of emphasizing a brand. Secondly, it is a traditional pattern with settled patterns from the past to the present. Third, it is a geometric pattern that appears both typically and atypically in various forms. Fourth, an abstract pattern type does not show a precise form or motif. Fifth, it is a colorful and diverse flower and plant pattern. Sixth, it is a landscape pattern that expresses nature and living space. Seventhly, it is an animal pattern type that expresses the appearance of an animal or the shape of the. Finally, it is a caricature pattern type using characters and various cartoonish motifs. Based on the analysis results of this study, creative and diverse design development of Jacquard and Intarsia knitwear and development of the knitwear market will take place.