• Journal of the East Asian Society of Dietary Life
• /
• v.14 no.5
• /
• pp.425-437
• /
• 2004

Medicinal plants are of great importance in providing healthcare to a large portion of the population in Korea. A number of plants are described in Dong-Ui-Bo-Gam for use in the treatment of allergic disorders, namely psoriasis, eczema, bronchial asthma, etc. In this study, we evaluated the effect of AllerQ, which is multi-complexes of various plants extracts such like Mori folium, Scutellaria baicallensis, Glycyrrhiza uralnsis, Mentha sacharinensis and Poncirus trifoliata on compound 48/80 induced anaphylactic shock, ovalbumin induced asthma in vivo and anti-IgE antibody induced hypersensitivity in vitro. We found antianaphylactic or antiallergic properties of AllerQ when given orally. AllerQ for prophylactic treatment for anaphylactic shocks have produced good results. AllerQ may modulate various aspects of immune function and allergic inflammation. In the present study, we analyse the effects of AllerQ on mast cell degranulation, mortality, cAMP/cGMP, O₂, H₂O₂ level, cyokine production and on the elicitation of IgE-mediated mast cell-dependent allergic inflammation in vivo and in vitro. We have established that AllerQ inhibited histamine release, cAMP/cGMP, O₂, H₂O₂ level, IL-4, tumor necrosis factor-alpha(TNF-α) and IL-6 production without having any significant physical change. These effects have been observed in mast cell(in vitro) and serum(in vivo) derived from three different origins that were activated by either immunological or non-immunological stimuli. These results suggest that the antianaphylactic and antiasthma tic action of AllerQ may be associated with an increase in the intracellular inhibition of the cAMP phosphodiesterase. Furthermore, AllerQ identified as potent inhibitors on O₂, H₂O₂ and cytokine activity. these data suggest that AllerQ may have an inhibitory role in mast cell-mediated allergic inflammation, and thus might be considered as an useful functional food.

• Journal of the Institute of Electronics Engineers of Korea CI
• /
• v.46 no.2
• /
• pp.114-123
• /
• 2009

Context-aware systems are reactive computing systems, aware of external context. Considering various sensors and actuators connected, application programming on top of such systems is known to be much more complex than in contentional ones. This paper suggests a formal framework for context-aware systems, by extracting their common properties. That makes a useful birds-eye view for the behaviors of a whole complex system, as a base for a convenient developing environment and systematic analysis. In this framework, reactive-ness is handled by event-condition-action rules and global state-transitions, which are essential in a lot of context-aware applications. In addition, behaviors of each elementary device are modelled with its own state-transitions, and tightly bound to the entire task.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.41 no.2
• /
• pp.24-31
• /
• 2018

As a system complexity increases and technology innovation progresses rapidly, leasing the equipment is considered as an important issue in many engineering areas. In practice, many engineering fields lease the equipment because it is an economical way to lease the equipment rather than to own the equipment. In addition, as the maintenance actions for the equipment are costly and need a specialist, the lessor is responsible for the maintenance actions in most leased contract. Hence, the lessor should establish the optimal maintenance strategy to minimize the maintenance cost. This paper proposes two periodic preventive maintenance policies for the leased equipment. The preventive maintenance action of policy 1 is performed with a periodic interval, in which their intervals are the same until the end of lease period. The other policy is to determine the periodic preventive maintenance interval minimizing total maintenance cost during the lease period. In addition, this paper presents two decision-making models to determine the preventive maintenance strategy for leased equipment based on the lessor's preference between the maintenance cost and the reliability at the end of lease period. The structural properties of the proposed decision-making model are investigated and algorithms to search the optimal maintenance policy that are satisfied by the lessor are provided. A numerical example is provided to illustrate the proposed model. The results show that a maintenance policy minimizing the maintenance cost is selected as a reasonable decision as the lease term becomes shorter. Moreover, the frequent preventive maintenance actions are performed when the minimal repair cost is higher than the preventive maintenance cost, resulting in higher maintenance cost.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.43 no.3
• /
• pp.243-253
• /
• 2020

As economic profits and social influences of firms grow with economic development and their organizational expansion, consumers increasingly require firms to have their social responsibility. Because social responsibility strongly influences corporate reliability, consumers' intention to purchase, customer loyalty to the products and the recognition of an ethical firm have gained attention as a concept of strategical importance. The prosperity of society should be proceeded for the sustainable development of a firm and the necessity of social responsibility should be emphasized to achieve virtuous circle structure that promotes growth. Additionally, the social responsibility should be proceeded to form trust on a firm. It is very important to change the recognition of consumers to purchase products and increase the profit of a company. This study aims to analyze how social responsibility properties of firms (economic, ethical, discretionary, and legal aspects as low-level factors of social responsibility which Carroll (1979) defined) affect corporate reliability and purchase intention. The analysis found that consumers trust in firms are positively influenced by ethical responsibility (0.391), economic responsibility (0.293), legal responsibility (0.251), and discretionary responsibility (0.248). The relationship between sub-factor of social responsibility and purchase intention is not significantly influenced by other explanatory variables. Corporate trust exerts a direct influence on purchase Intention (0.456). The social responsibility of a firm didn't influence a direct purchase intention. It was found that it brought positive effect on the purchase intention in the course of forming trust. This study suggests that firms should make efforts to understand the relationship between corporate trust and purchase intention along with the characteristics of social responsibility that consumers recognize and improve management strategies for mutual complementary interests.

• Journal of the Korea Concrete Institute
• /
• v.23 no.1
• /
• pp.23-30
• /
• 2011

In this study, deterioration degrees of concrete were investigated at laboratory under seawater attack and cycling freeze-thaw, which are major durability performance deterioration factors of concrete. Deteriorations of mixed concrete using Portland & blended cement were examined by instrumental analysis of changes in relative dynamic modulus of elasticity and compressive strength. After 520 cycles of freeze-thaw, relative dynamic modulus of elasticity and compressive strength of concrete mixed with normal Portland and LHC over 75% showed relatively low resistance of approximately 44% of those values of SRC. Concrete replaced with 50% fine powder of blast furnace slag showed the most excellent freeze-thaw resistance among the tested blended cement concrete.

• The Bulletin of The Korean Astronomical Society
• /
• v.41 no.1
• /
• pp.37.2-37.2
• /
• 2016

There exist scaling relations that link the mass of supermassive black holes with both the velocity dispersion and the mass of the central stellar cusp of their host galaxies. This implies that galaxies co-evolve with their central black holes, potentially through the feedback from actively accreting supermassive black holes (AGN). We use integral field spectroscopy data from the 8.2m Gemini-North telescope to investigate ionized gas outflows in luminous local (z<0.1) Type 2 AGN. Our sample of 6 galaxies was selected based on their [OIII] dust-corrected luminosity (>$10^{42}erg/s$) and signatures of outflows in the [OIII] line profile of their SDSS spectra. These are arguably the best candidates to explore AGN feedback in action since they are < 1% of a large local type 2 AGN SDSS sample selected based on their [OIII] kinematics. Expanding on previously reported results concerning the kinematic decomposition and size determination of these outflows, here we report their photoionization properties and energetics. We find strong evidence that connect the extreme kinematics of the ionized gas with AGN photoionization. The kinematic component related to the AGN-driven outflow is clearly separated from other kinematic components, such as gravitation- or stellar-driven motions, on the velocity and velocity dispersion diagram. Our spatially resolved kinematic analysis reveals that up to 90% of the mass and kinetic energy of the outflow is contained within the central kiloparcec of the galaxy. The total mass and kinetic energy of the outflow correlate well with the AGN bolometric luminosity, resulting in energy conversion efficiencies between 0.01% and 1%. Intriguingly, we detect ubiquitous signs of ongoing circumnuclear star formation. Their small size, the centrally contained mass and energy, and the universally detected circumnuclear star formation cast doubts on the potency of these AGN-driven outflows as agents of negative feedback.

• Korean Chemical Engineering Research
• /
• v.56 no.5
• /
• pp.625-630
• /
• 2018

The electrostatic interactions were investigated between the zirconia and the 11-Mercaptoundecylphosphoric-acid layer formed on gold surfaces for their complex structures. For the investigation, the atomic force microscope was used to measure the surface forces between the surfaces as a function of the salt concentration and pH value. The forces were analyzed with the Derjaguin-Landau-Verwey-Overbeek theory to estimate the potential and charge density of the surfaces for each condition. The concentration dependence of the surface properties, found from the measurement at pH 4 and 8, was consistent with the prediction from the law of mass action. The pH dependence was explained with the ionizable groups on the surface. It was found that the 11-Mercaptoundecylphosphoric-acid layer had higher values for the surface charge densities and potentials than the zirconia surfaces at pH 4 and 8, which may be attributed to the ionized-functional-groups of the layer.

• Membrane and Water Treatment
• /
• v.11 no.5
• /
• pp.323-331
• /
• 2020

With the increasing demand on reverse osmosis (RO) membranes for water purification worldwide, the number of disposed membrane elements is expected to increase accordingly. Thus, recycling and reuse of end-of-life RO membranes should be a global environmental action. In this work, we aim to reuse the spent RO membrane for nanofiltration (NF) and ultrafiltration (UF) process by subjecting the spent membrane to solvent and oxidizing solution treatment, respectively. Our results showed that solvent-treated RO membrane could perform as good as commercial NF membrane by achieving similar separation efficiencies, but with reduced water permeability due to membrane surface fouling. By degrading the polyamide layer of RO membrane, the transformed membrane could achieve high water permeability (85.6 L/㎡.h.bar) and excellent rejection against macromolecules (at least 87.4%), suggesting its reuse potential as UF membrane. More importantly, our findings showed that in-situ transformation on the spent RO membrane using solvent and oxidizing solution could be safely conducted as the properties of the entire spiral wound element did not show significant changes upon prolonged exposure of these two solutions. Our findings are important to open up new possibilities for the discarded RO membranes for reuse in NF and UF process, prolonging the lifespan of spent membranes and promoting the sustainability of the membrane process.

• Journal of Advanced Marine Engineering and Technology
• /
• v.37 no.5
• /
• pp.533-540
• /
• 2013

Prime movers in engine rooms inherently are much affected by the adjustment of their governors for the steady state and transient properties, consequently requiring that marine engineers shall be well familiar with the way to manage governor dials for normal operation. The hydro-mechanical governors basically have different control characteristics and adjustment parameters of stability from digital governors. The former include compensation mechanism using dash pot while the control algorithm of the latter is usually based on the PID action. This study is for configuring a simulation module to let trainees practice how to adjust dials for stability on hydraulic governors in the view that the practice by real governors and engines is time consuming and high cost for operation. The governor module includes the adjusting points such as speed set, speed droop, needle valve and compensation pointer with engine module of $2^{nd}$ order coupled. The results of simulation showed satisfactory responses as a training tool for the adjustment of control parameters.

• Elastomers and Composites
• /
• v.41 no.2
• /
• pp.88-96
• /
• 2006

The self-sealing rubber material for a fuel cell which has self-sealing ability, in case of fuel leakage, was studied. Cure characteristics, density, swelling, and surface morphology of foamed natural rubber were investigated with carbon black and with processing oil within the range of $10{\sim}30phr$. The rheological properties indicated that the value of $ts_2$ and the value of $Tc_{90}$ were increased with increasing a content of processing oil, while carbon black did not show a similar trend. A difference in density by foaming was decreased to one fifth scale compared to the initial value. According to the swelling test of foamed natural rubber in fuel C, isooctane and toluene, all the self-sealing action was finished in two minutes. From the SEM image for the surface of rubber compounding, a foaming by sodium bicarbonate was found to be unequal and consecutive foaming cell.