• Journal of Life Science
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• v.27 no.9
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• pp.975-985
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• 2017

To investigate the beneficial effects of an agar gel mask (AGM) on UV-induced photoaging, SKH-1 hairless mice were treated with a topical application of AGM and an AGM dipped in essence (AGMdE). The mice were divided into an no radiation group, UV + AGM, UV + AGMdE, and UV + vehicle (PBS) treatment groups. Alterations in skin wrinkles, skin phenotype, histological structures, oxidative status, and toxicity were then evaluated during 4 weeks of exposure. The topical application of AGM and AGMdE inhibited wrinkle formation, suppressed the erythema index, prevented transepidermal water loss, and enhanced skin hydration. In addition, epidermal thickness recovered to a similar level as that in the no irradiation group in the UV + AGM and UV + AGMdE treatment groups compared with the UV + vehicle (distilled water) group. Furthermore, the expression levels of matrix metalloproteinase-1 (MMP-1) and tyrosinase were reduced in the UV + AGM and UV + AGMdE treatment groups, although the highest level varied. Moreover, superoxide dismutase (SOD) activity was significantly lower in the UV + AGM and UV + AGMdE treatment groups as compared with the UV + vehicle group. No significant alterations induced by most toxic compounds were measured in serum biochemical markers and liver and kidney histological features of the UV + AGM and UV + AGMdE treatment groups. These results suggest that AGM may protect against skin aging by regulating skin morphology, histopathological structures, and oxidative conditions.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.6
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• pp.757-765
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• 2009

Bread was prepared with different concentrations of Pleurotus eryngii powder ($2.5{\sim}10.0%$), and the fermentation characteristics were investigated. While pH of dough increased, fermentation power of dough expansion by fermentation decreased with the increase of Pleurotus eryngii powder added. Although bread weight decreased, there were no significant differences in dough weight, dough yield and baking loss as Pleurotus eryngii powder content increased. In case of volume and specific volume, they were significantly decreased as Pleurotus eryngii powder content increased. Size of bread decreased gradually and aircell uniformity became bigger and random as Pleurotus eryngii powder content increased. As the results of color values, L and b values of crust decreased; however, there was no significant difference in a value. L value of crumb decreased although a and b values increased by adding the Pleurotus eryngii powder content. In the textual characteristics, hardness, gumminess and brittleness of bread significantly increased as Pleurotus eryngii powder content increased. Cohesiveness and springiness of bread decreased as Pleurotus eryngii powder content increased. In case of free amino acid, Glu content was the largest in most samples and most amino acid contents increased by adding the Pleurotus eryngii powder content except for Asp. In descriptive test, scores of color, flavor, hardness and palatability increased, however aircell uniformity, springiness and moistness decreased as Pleurotus eryngii powder content increased. As the results of preference test, color was the best preferred in control${\sim}5.0%$ groups without significant difference. The preference of flavor and texture was in the order of 2.5% group> 5.0% group> 7.5% group> control> 10.0% group as 2.5% group was the most preferred.

• Journal of Korean Society of Forest Science
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• v.98 no.1
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• pp.55-65
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• 2009

Annex I parties continued its consideration of how to address, the definitions, modalities, rules and guidelines for the treatment of Land Use, Land-use Change and Forestry (LULUCF) in the second commitment period of the Kyoto Protocol by the year of 2009. In the AWG-KP conference held in Accra, Ghana in 2008, four alternatives (gross-net carbon accounting, net-net with base year or base period accounting, net-net with forward looking baseline accounting, and land-based accounting method) for negotiations were decided in order to revise gross-net accounting method applied during the first commitment period of the Kyoto Protocol. In this study, alternative scenarios are set in consideration with reporting system (voluntary or compulsory), discount factors and cap about these three alternatives except for the method of net-net with forward looking baseline accounting, and then estimates the Removal Unit (RMU) among the countries. In the case that article 3.4 activities under the Kyoto Protocol revises from voluntary reporting to mandatory reporting, it is estimated that the loss of RMU would be huge in Russia, Australia, New Zealand, as well as Canada potentially. Net-net with base year or base period carbon accounting and land-based carbon accounting method have big difference of RMU in accordance with the base year or the base period. So the more unfavorable the country with a lot of old-age forests was, the closer the base year or period comes to the commitment period in the context of RMU. If it is getting lowered for the current rate of 85% in discount factors, RMU is getting higher to the whole countries. Therefore in Korea with little potential for afforestation and reforestation, there was the most sensitive response to the change of discount factors. Post-2012 LULUCF hereafter, it is strongly expected for the succession of current carbon accounting system which is voluntary reporting of gross-net carbon accounting and the activity for article 3.4. Other carbon accounting method is hard to accept in aspect that there is big differentiated interests among the countries and it is required enormous cost and time to develop reliable method. Provide for Post-2012 mandatory greenhouse gas reduction, Korea needs to have a competitive negotiation strategies differentiated from Annex I countries. The most reliable alternative would be to lower the discounting factors about the activities for forest management.

• The Korean Journal of Air & Space Law and Policy
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• v.29 no.1
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• pp.33-66
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• 2014

While the numbers of overseas travelers has been increased rapidly each year, the numbers of passengers in the aircraft also has continued to be increased gradually. In the mist of these increasing numbers, such accidents as threatening an aircraft safety like riot, aircraft hijacking and terrorism have happened constantly. In these circumstances, South Korean government has prescribed "Aviation on Security Act" in accordance with the Convention on International Civil Aviation and other international agreements. This act aims to prevent illegal activities and illegal items on the aircraft to ensure the safety and security of civil aviation. However, this act is not sufficiently regulating all the illegal crimes and illegal items on the flight. For the worse, there is a lack of effective supervisory capacity. Likewise, the inherent problems of the current laws relating to the prevention of the illegal items on the aircraft are appearing on the surface continually. Above all, illegal items on the aircraft are directly connected to the issue of aviation safety and security as well as a safe utilization of the flight service. Thus, when there occurs a serious accident on board, it surely would be led to a huge economic loss not mentioning the loss of lives following the accident. Therefore safety of the flight passengers cannot be guaranteed without ensuring the safety of aircraft facilities and good supervisory mechanism of illegal items on the aircraft. Accordingly, establishing a safe operation order tends to influence economy and tourism of a country in no small measure. Therefore, it is an urgent issue to settle down a reasonable and adequate supervisory regulations regarding the prevention of the illegal items on the aircraft. Consequently, in this article, I studied on a reasonal and effective mechanism to control the prevention of the illegal items and illegal acts on the aircraft in order to ensure a safety and security of civil aircraft.

• Archives of design research
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• v.19 no.2 s.64
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• pp.261-272
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• 2006

As we cannot think of our lives without a nation, it is closely related to almost every part of our daily lives. The role of government is becoming more important in the complex modern society as an essential element of national authority even though the government has indirect and secondary characteristics in its functional performance. Therefore, the government has to be efficient in planning and executing its policies, and it needs to be representative and fair as part of a national authoritative community. In the 21st century when symbolic and cultural importance of images are becoming more important, it is crucial for the government organizations to have an integrated identity design system that can satisfy both of these requirements of the government. However, the C.I.(Corporate Identity) of each Korean administrative branch has been developed separately and sporadically, which resulted in lack of consistency as part of the government. Shape and material of their C.I.s that follow short term design trend and popularity also lack uniqueness which can be distinguished from those of any private corporation. This may show that our government lacks systematic administrative capability, since image of a feature represents its characteristics and reality, and their recognition and evaluation from others become identity of the feature. In this perspective, the purpose of this thesis is to suggest an identity design system that has certain rules and regularity with wide variety of possible alterations for the central administration in Korea. In order to represent this visually, identity design system with both integrity and variety of possible alteration is created based on traditional Korean culture, especially the concept of Umyang-ohaeng and Samjae.

• Journal of the Korean Society for Nondestructive Testing
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• v.26 no.4
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• pp.211-219
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• 2006

The UET(ultrasound excited thermography) for the ,eat-time diagnostics of the object employs an infrared camera to image defects of the surface and subsurface which are locally heated using high-frequency putted ultrasonic excitation. The dissipation of high-power ultrasonic energy around the feces of the defects causes an increase In temperature. The defect's image appears as a hot spot (bright IR source) within a dark background field. The UET for nondestructive diagnostic and evaluation is based on the image analysis of the hot spot as a local response to ultrasonic excited heat deposition. In this paper the applicability of VET for fast imaging of defect is described. The ultrasonic energy is injected into the sample through a transducer in the vertical and horizontal directions respectively. The voltage applied to the transducer is measured by digital oscilloscope, and the waveform are compared. Measurements were performed on four kinds of materials: SUS fatigue crack specimen(thickness 14mm), PCB plate(1.8 mm), CFRP plate(3 mm) and Inconel 600 plate (1 mm). A high power ultrasonic energy with pulse durations of 250ms Is injected into the samples in the horizontal and vertical directions respectively The obtained experimental result reveals that the dissipation loss of the ultrasonic energy In the vertical injection is less than that in the horizontal direction. In the cafe or PCB, CFRP, the size of hot spot in the vortical injection if larger than that in horizontal direction. Duration time of the hot spot in the vertical direction is three times as long as that in the horizontal direction. In the case of Inconel 600 plate and SUS sample, the hot spot in the horizontal injection was detected faster than that in the vertical direction

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.34 no.1
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• pp.85-95
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• 1998

The broadband ultrasonic transducers have been designed to use in obtaining the broadband echo signals from fish schools in relation to the identification of fish species. The broadening of bandwidth was achieved by attaching double acoustic matching layers on the front face of a Tonpilz transducer consisted of an aluminum head, a piezoelectric ring, a brass tail and to evaluate the performance characteristics, such as the transmitting voltage response(TVR) of transducers. The constructed transducers were tested experimentally and numerically by changing the parameters such as impedances and thicknesses of the head, tail and matching layers, in the water tank. Also, the developed transducer was excited by a chirp signal and the received chirp waveforms were analyzed. According to the measured TVR results, the available 3 dB bandwidth of the transducer with double matching layers of an $Al_O_3/epoxy$ composite of 7 mm thick and a polyurethane window of 18 mm thick was 7.3 kHz with a center frequency of 38.8 kHz, and the maximum and the minimum values of the TVR in this frequency region were 135.7 dB and 132.7 dB re $1\;{\mu}Pa/V$ at 1 m, respectively. Also, the available 3 dB bandwidth of the transducer with double matching layers of an $Al_O_3/epoxy$ composite of 11 mm thick and a polyurethane window of 15 mm thick was 6.2 kHz with a center frequency of 38.6 kHz, and the maximum TVR value in the frequency region was 136.3 dB re $1\;{\mu}Pa/V$ at 1 m. Reasonable agreement between the experimental results and the numerical results for the TVR of the developed transducers was achieved. The frequency dependant characteristics of experimentally observed chirp signals closely matched to the measured TVR results. These results suggest that there is potential for increasing the bandwidth by varying other parameters in the transducer design and the material of the acoustic matching layers.

• Korean Journal of Environmental Agriculture
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• v.37 no.4
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• pp.268-276
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• 2018

BACKGROUND: In the month of January 2018, fine dust alerts and warnings were issued 36 times for $PM_{10}$ and 81 times for PM2.5. Air quality is becoming a serious issue nation-wide. Although interest in air-purifying plants is growing due to the controversy over the risk of chemical substances of regular air-purifying solutions, industrial spread of the plants has been limited due to their efficiency in air-conditioning perspective. METHODS AND RESULTS: This study aims to propose a vegetation-based bio-filter system that can assure total indoor air volume for the efficient application of air-purifying plants. In order to evaluate the quantitative performance of the system, time-series analysis was conducted on air-conditioning performance, indoor air quality, and comfort index improvement effects in a lecture room-style laboratory with 16 persons present in the room. The system provided 4.24 ACH ventilation rate and reduced indoor temperature by $1.6^{\circ}C$ and black bulb temperature by $1.0^{\circ}C$. Relative humidity increased by 24.4% and deteriorated comfort index. However, this seemed to be offset by turbulent flow created from the operation of air blowers. While $PM_{10}$ was reduced by 39.5% to $22.11{\mu}g/m^3$, $CO_2$ increased up to 1,329ppm. It is interpreted that released $CO_2$ could not be processed because light compensation point was not reached. As for the indoor comfort index, PMV was reduced by 83.6 % and PPD was reduced by 47.0% on average, indicating that indoor space in a comfort range could be created by operating vegetation-based bio-filters. CONCLUSION: The study confirmed that the vegetation-based bio-filter system is effective in lowering indoor temperature and $PM_{10}$ and has positive effects on creating comfortable indoor space in terms of PMV and PPD.

• Journal of Life Science
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• v.29 no.3
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• pp.295-302
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• 2019

Liquiritigenin (LG) is a chiral flavonoid isolated from the roots of licorice. It exhibits multiple biological activities including anti-oxidant, anti-cancer, and anti-inflammatory effects. In particular though, the anti-cancer activity of LG in oral squamous cell carcinoma has yet to be elucidated, and LG-induced apoptosis in oral squamous cell carcinoma remains poorly understood. In the present study, we tested the role of LG in inducing apoptosis in oral squamous cell carcinoma cells. LG treatment of HN22 cells resulted in a dose-dependent inhibition of cell viability as detected by a 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide assay. The induction of apoptosis in terms of Annexin V/7-Aminoactinomycin D staining, sub-G1 population, and multi-caspase activity were assessed with a $Muse^{TM}$ Cell Analyzer. Flow cytometric analysis revealed that LG treatment resulted in G2/M arrest in cell cycle progression and downregulation of cyclin B1 and CDC2 expression in a concentration-dependent manner. It also resulted in significant upregulation of p27. In addition, LG was seen to trigger the generation of reactive oxygen species and induce CCAAT/enhancer-binding protein homologous protein and 78-kDa glucose-regulated protein in concentration-dependent upregulation. The LG treatment of HN22 cells led to a loss of mitochondrial membrane potential (${\Delta}{\Psi}m$); it also reduced the levels of anti-apoptotic protein and increased the expression of apoptotic protease activating factor-1, cleaved poly (ADP-ribose)polymerase and Bax. Overall, our results indicate that the pro-apoptotic effects of LG in HN22 cells depend on the activation of both intrinsic and extrinsic signaling pathways. Thus, our results suggest that LG constitutes a natural compound with a potential role as an anti-tumor agent in oral squamous cell carcinoma.

• Journal of Climate Change Research
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• v.1 no.2
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• pp.121-131
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• 2010

This study was carried out to evaluate spatial variations in rice production areas by simulating rice growth and yield with CERES-Rice growth model under GCM $2{\times}CO_2$ climate change scenarios. A modified window version(v4.0) of CERES-Rice was used to simulate the growth and development of three varieties, representing early, medium, and late maturity classes. Simulated growth and yield data of the three cultivars under the climate for 1971 to 2000 was set as a reference. Compared with the current normal(1971 to 2000), heading period from transplanting to heading date decreased by 7~8 days for the climate in $2^{\circ}C$ increase over normal, and 16~18 days for the climate in UKMO with all maturity classes, while change of ripening period from heading to harvesting date was different with maturity classes. That is, physical maturity was shortened by 1~3 days for early maturity class and 14~18 days for late maturity class under different climate change scenarios. Rice yield was in general reduced by 4.5%, 8.2%, 9.9%, and 14.9% under the climate in $2^{\circ}C$, $3^{\circ}C$, $4^{\circ}C$, and about $5^{\circ}C$ increase, respectively. The yield reduction was due to increased high temperature-induced spikelet sterility and decreased growth period. The results show that predicted climate changes are expected to bring negative effects in rice production in Korea. So, it is required for introduction of new agricultural technologies to adapt to climate change, which are, for example, developing new cultivars, alternations of planting dates and management practices, and introducing irrigation systems, etc.