• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.28 no.2
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• pp.143-149
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• 2022

PCS needs to freely switch AC and DC to connect the battery, external AC loads and renewable energy in both directions for energy efficiency. Whenever converting happens, power loss inevitably occurs. Minimization of the power loss to save electricity and convert it for usage is a very critical function in PCS. PCS plays an important role in the ESS(Energy Storage System) but the importance of stabilizing semiconductors on PCB(Printed Circuit Board) should be empathized with a risk of failure such as a fire explosion. In this study, the temperature variation inside PCS was reviewed by cooling fan on top of PCS, and the vibration characteristics of PCS were analyzed during truck transportation for reliability of the product. In most cases, a cooling fan is mounted to control the inner temperature at the upper part of the PCS and components generating the heat placed on the internal aluminum cooling plate to apply the primary cooling and the secondary cooling system with inlet fans for the external air. Results of CFD showed slightly lack of circulating capacity but simulated temperatures were durable for components. The resonance points of PCS were various due to the complexity of components. Although they were less than 40 Hz which mostly occurs breakage, it was analyzed that the vibration displacement in the resonance frequency band was very insufficient. As a result of random-vibration simulation, the lower part was analyzed as the stress-concentrated point but no breakage was shown. The steel sheet could be stable for now, but for long-term domestic transportation, structural coupling may occur due to accumulation of fatigue strength. After the test completed, output voltage of the product had lost so that extra packaging such as bubble wrap should be considered.

• The Journal of Korean Medicine
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• v.28 no.2 s.70
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• pp.54-65
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• 2007

Objectives : In the present study, the author investigated whether Naenghyo-hwan(NHH) significantly affect mucin secretion from airway epithelial cells. Methods : Confluent hamster tracheal surface epithelial (HTSE) cells were metabolically radiolabeled with 3H-glucosamine for 24 hrs and chased for 30 min in the presence of NHH to assess the effect of the agent on 3H-mucin secretion. Total elutionprofiles of control spent media and treatment sample through Sepharose CL-4B column were analysed. Effect of NHH on contractility of isolated tracheal smooth muscle was investigated. Also, effect of the agent on MUC5AC gene expression in cultured NCI-H292cells was investigated. Possible cytotoxicities of the agent were assessed by measuring both lactate dehydrogenase (LDH) release from HTSE cells and examining the rate of survival and proliferation of NCI-H292 cells. Results : NHH significantly increased mucin secretion from cultured HTSE cells, with significant cytotoxicity. NHH chiefly affected the 'mucin' secretion. NHH inhibited ACh-induced contraction of isolated tracheal smooth muscle. NHH disturbed both the extraction of total RNA from NCI-H292 cells and polymerase chain reaction, nonspecifically. Therefore, in this experiment, theeffect of NHH on the expression levels of MUC 5AC gene in cultured NCI-H292 cells could not be elucidated. Conclusions : The author suggests that the effect of NHH with their components should be further investigated and it is valuable to find, from oriental medical prescriptions, novel agents which might regulate mucin secretion from airway epithelial cells.

• The Journal of Internal Korean Medicine
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• v.41 no.4
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• pp.553-562
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• 2020

Objective: To investigate the vasodilatory effect of Sipjeondaebo-tang by inhibiting RhoA activity in vascular cells during cold exposure. Methods: Human vascular endothelial cells and pericytes were pretreated with Sipjeondaebo-tang for 30 min, followed by incubation at 37 ℃ (control) or 25 ℃ (cold exposure) for 30 min. Activation of endothelin-1-mediated RhoA in pericytes was assessed by pretreating the cells with Sipjeondaebo-tang for 30 min, followed by incubation with endothelin-1 at 37 ℃ for 30 min. Western blotting was performed to measure the expression of active RhoA. Endothelin-1 and nitric oxide release from endothelial cells was examined with enzyme-linked immunosorbent assay kits. The formation of stress fibers and focal adhesion complexes was analyzed by immunocytochemistry. Results: Cold treatment activated RhoA in both pericytes and vascular endothelial cells, whereas Sipjeondaebo-tang treatment inhibited this activation. Sipjeondaebo-tang treatment also reversed the cold-mediated production of endothelin-1 and nitric oxide. Cold exposure promoted the formation of stress fibers and focal adhesion complexes by increasing the expression of phospho-focal adhesion complex kinase, whereas Sipjeondaebo-tang treatment suppressed this response. Conclusions: These findings suggested that Sipjeondaebo-tang inhibits cold-induced RhoA activation and its related pathway components, including endothelin-1 and nitric oxide, in vascular cells. Therefore, Sipjeondaebo-tang could be beneficial for the treatment of Raynaud's phenomenon.

• Journal of Physiology & Pathology in Korean Medicine
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• v.19 no.6
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• pp.1666-1672
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• 2005

Oriental medicinal drugs have a broad spectrum of clinical use for the cure of nervous system diseases including brain ischemic damages or neuropathies. Yet, specific drugs or drug components used in the oriental medicine in relation to none fiber regeneration are not known. In the present study, possible growth promoting effects of oriental medicinal drugs were investigated in the injured sciatic nerve system in the rat. By immunofluorescence staining, we found that Jahageo (JHG, Hominis placenta) increased Induction levels of axonal growth associated protein GAP-43 in the rat sciatic none. Small growth promoting activity was found in Golsebo (GSB, Drynariae rhizoma) and Baikhasuo (BHSO, Polygoni multiflori radix) drugs. JHG also increased cell cycle protein Cdc2 levels in the injured area of the sciatic nerves. Immunofluorescence staining indicated that induced Cdc2 protein was mostly localized in the Schwann cells in the injury area, implying that JHG activity might be related to increased Schwann cell proliferation during axonal regeneration. Moreover, levels of phospho-extracellular signal-regulated (ERK) pathway in the injured neNes were elevated by JHG treatment while levels of total ERK were unaltered. In vivo measurement of axonal regeneration using retrograde tracer showed that JHG, GSB and BHSO significantly enhanced Dil-labeled regenerating motor neurons compared with saline control. The present data suggest that oriental medicinal drugs such as JHG, GSB, and BHSO may be a useful target for developing specific drugs of axonal regeneration.

• Smart Structures and Systems
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• v.14 no.5
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• pp.765-784
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• 2014

In comparison with conventional shape memory actuated structures, antagonistic shape memory alloy (SMA) actuators permits a fully reversible two-way response and higher response frequency. However, excessive internal stress could adversely reduce the stroke of the actuators under repeated use. The two-way shape memory effect might further decrease the range of the recovered strain under actuation of an antagonistic SMA actuator unless additional components (e.g., spring and stopper) are added to regain the overall actuation capability. In this paper, the performance of all four possible types of SMA actuation schemes is investigated in detail with emphasis on five key properties: recovered strain, cyclic degradation, response frequency, self-sensing control accuracy, and controllable maximum output. The testing parameters are chosen based on the maximization of recovered strain. Three types of these actuators are antagonistic SMA actuators, which drive with two active SMA wires in two directions. The antagonistic SMA actuator with an additional pair of springs exhibits wider displacement range, more stable performance under reuse, and faster response, although accurate control cannot be maintained under force interference. With two additional stoppers to prevent the over stretch of the spring, the results showed that the proposed structure could achieve significant improvement on all five properties. It can be concluded that, the last type actuator scheme with additional spring and stopper provide much better applicability than the other three in most conditions. The results of the performance analysis of all four SMA actuators could provide a solid basis for the practical design of SMA actuators.

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.4
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• pp.451-458
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• 2009

This experimental study was conducted to investigate macroscopic characteristics of the flash boiling spray with tow component mixing fuel. Homogeneous Charge Compression Ignition (HCCI) is a newer combustion method for internal combustion engines to reduce nitrogen oxide and particulate matter simultaneously. But it is difficult to put this combustion method to practical use in an engine because of such problems as instability of combustion in low load operating conditions and knocking in high load operating conditions. In HCCI, combustion characteristics and exhaust emissions depend on conditions of air/fuel mixture and chemical reactions of fuel molecules. The fuel design approach is achieved by mixing two components which differ in properties such as density, viscosity, volatility, ignitability and so on. We plan to apply the fuel design approach to HCCI combustion generated in a real engine, and examine the possibility of mixture formation control using the flash boiling spray. Spray characteristics of two component fuel with a flash boiling phenomenon was investigated using Shlieren and Mie scattering photography. Test fuel was injected into a constant volume vessel at ambient conditions imitated injection timing BTDC of a real engine. As a result, it was found that a flash boiling phenomenon greatly changed spray structure, especially in the conditions of lower temperature and density. Therefore, availability of mixture formation control using flash boiling spray was suggested.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.707-710
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• 2011

System safety is defined as the state where the hazard risks due to internal system, interface, operation and maintenance are controlled as acceptable levels. It is represented and evaluated either with the risk level of each risk factor with the consideration of operation environments or with Safety Integrity Level (SIL) which is the system functional safety without considering application environments. The assessment results are issued in forms of certificates and they are reused in many cases. However, the conditions and restrictions for different application environments vary in each case, therefore, additional evaluation on the preconditions of assessment in comparison with the actual application environment must be carried out. For the area of train control, TR 50506-1 has been established based on the IEC 62425 (international standard for safety of train control system by RSSB) and EN 50129 (Europe standard) for the further assessment. In this paper, the analysis on TR 5056-1 has been conducted in depth. The purpose of the study is to determine the requirements for inter-acceptability including scope, procedures, principles, examination and suitability. The results can be utilized for the system safety maintenance when new devices or components are introduced in conventional systems.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.9
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• pp.1547-1553
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• 2008

This paper presents a method that generates various facial expressions of vector graphic character by using the simplified principle component vector. First, we analyze principle components to the nine facial expression(astonished, delighted, etc.) redefined based on Russell's internal emotion state. From this, we find principle component vector having the biggest effect on the character's facial feature and expression and generate the facial expression by using that. Also we create natural intermediate characters and expressions by interpolating weighting values to character's feature and expression. We can save memory space considerably, and create intermediate expressions with a small computation. Hence the performance of character generation system can be considerably improved in web, mobile service and game that real time control is required.

• Tuberculosis and Respiratory Diseases
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• v.46 no.5
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• pp.697-708
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• 1999

Background : Leukotriene (LT) $C_4$, $D_4$, and $E_4$, the main components of slow-reacting substance of anaphylaxis (SRS-A), have been suggested to play an important role in bronchial asthma such as antigen-induced bronchoconstriction, airway hyperreactivity, and pulmonary eosinophil accumulation. The purpose of this study was to evaluate the effects of treatment with the cysteinyl-LTs (cys-LTs) antagonist, pranlukast on allergen-induced guinea pig asthma model. Methods : Guinea pigs of treatment and placebo groups were sensitized by subcutaneous injection of ovalbumin(OVA) and challenged by inhalation of aerosolized OVA (1% weight/volume OVA). Normal control group did not sensitize with OVA. Oral ingestion of pranlukast and normal saline to the treatment and placebo groups was performed. In the treatment and placebo groups, airway resistance was measured before and after oral ingestion. Serum $LTC_4$ and eosinophilic infiltration of the bronchiolar and peribronchiolar tissues were measured after ingestion in the treatment and placebo groups. Results : Allergen-induced airway constriction developed in 20 (8 in treatment group, 12 in placebo group) among 35 guinea pigs. Airway resistance was significantly decreased at 3 and 6 minutes after OVA challenge in the pranlukast treatment group. In the placebo group, there was no difference of airway resistance between before and after saline ingestion. Serum $LTC_4$ levels showed 348.4 pg/ml in the treatment group, 373.9 pg/ml in the placebo group, and 364.4 pg/ml in the control group. There were no statistically significant difference between treatment and placebo group (p=0.232), and treatment and control group (p=0.501). Eosinophilic infiltrations in the peribronchiolar region per one-microscopic field ($\times$400 high power fields) demonstrated 7.06 in the treatment group, 19.2 in the placebo group, and 4.50 in the control group. There was significant decrement of eosinophilic infiltration in the treatment group which was compared with placebo group (p=0.001). Conclusion : These results demonstrate that pranlukast, a cys-LTs receptor antagonist, can attenuate allergen induced early-phase bronchoconstriction and eosinophilic infiltration in the bronchiolar tissues.

• 지역과문화
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• v.8 no.4
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• pp.1-22
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• 2021

This ethnographic study aimed to understand the emotional labor of traditional performing artists who hide and control their emotions in performances and the components and characteristics of their emotional labor by means of in-depth interviews with traditional performing artists and Giorgi's analysis method. As a result of the analysis, first, the factors that lead to emotional labor of traditional performing artists can be divided into external and internal ones. The external factors arose from expressing various emotions while creating or suppressing their own emotions in an effort to draw out the emotions of the audience. Also, emotional labor occurred depending on the performance place, performance type and audience reaction. The internal factors consisted of the emotional burden experienced due to concerns over mistakes and audience satisfaction as they voluntarily commit themselves to the performance in order to satisfy the audience. Second, complex emotions that remain after the performance sometimes lead to aftereffects of emotional labor. Third, factors of emotional labor that originate from belonging to an organization had an influence, which resulted in their considering job change or resignation. Fourth, emotional labor arises from the specificity of the traditional performing arts field, that is, negative perceptions and unfair internal practices of traditional performing arts. The study showed that traditional performing artists relieve their emotional labor through hobbies and chatting with colleagues, and took the emotional labor as granted, not recognizing that the occupational emotional labor as emotional labor. This study is significant in that it recognized and analyzed traditional performing artists as emotional workers and focused on the emotional labor components of traditional performing artists.