• Clinical and Experimental Reproductive Medicine
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• v.26 no.3
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• pp.363-368
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• 1999

This study was to confirm whether the vitrification method using EFS40 freezing solution has detrimental effect on the cytoskeleton and chromosome constitution of the immature mouse oocytes by indirect immunocytochemistry and chromosome analysis. Immature mouse oocytes were vitrified using EFS40 (40% EG, 18% ficoll, 0.5 M sucrose diluted in M2 medium), thawed and then survived oocytes were in vitro matured for 16 hr. When the microtubule morphology and micro filament distribution in vitrified-thawed immature mouse oocytes were examined, normal percentage of two cytoskeleton in vitrified group (93.9 and 100.0%) was not significantly different from that in control (100.0 and 100.0%) and exposed group (94.4 and 100.0%). The rate of oocytes containing a normal chromosome number in vitrified group was 65.8%, this result was not significantly different from that in control (79.6%) and exposed group (69.0%). These results indicated that exposure to cryoprotectant or freezing has not effect on the alteration of cytoskeleton morphology and the chromosome constitution of mouse oocytes and that our vitrification methods using EFS40 freezing solution was suitable for the cryopreservation of immature mouse oocytes.

• Journal of the Korean Society for Railway
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• v.14 no.4
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• pp.313-319
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• 2011

In a modern society, various type of transportation modes are utilized, among them the subway system is the one of the main transportation mode which more than 7.21 million people ride a day in Seoul. Due to the increased interests on the indoor air quality (IAQ) of underground facilities, public concerns on IAQ of subway system are increasing also. Platform screen door (PSD) recently installed at the whole stations of Seoul subway and tunnel washing-out appeared to be effective in reducing particulate matters in the platform and tunnel. However there has not been any attempt to improve IAQ of subway cabin inside. Most technologies for removing airborne particulate matters are known to be difficult to adopt on the subway cabin due to the problem of maintenance cost. Therefore, the object of this study is a practical development of cabin air cleaning system which can reduce the concentration of airborne particles and harmful gases at the same time. In this paper, we focused on the development of particle removing system utilizing a roll-filter for increasing operating time of air filter. The prototype of system was designed and manufactured based on the numerical prediction results. For rollfilter device, 5 candidate filter materials were tested in point of particle collection efficiency and pressure drop. It was found that the electrically charged filter material showed the highest performance among them.

• Journal of the Korean Society for Railway
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• v.18 no.5
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• pp.439-446
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• 2015

The turnout system, which determines the direction of the train, is not only a key system but also a vulnerable system. Failure of this system may lead to a delay of the train or even casualties. In this light, it is necessary to precisely the conditions of the turnout system. Currently, ROADMASTER of Germany is used as a diagnostic system in Korea. However, a new diagnostic system should be developed for optimized operation of the turnout system with maintenance that is suitable for the Korean railway environment. In this paper, a Fault Tree Analysis for the representative faults of the turnout system is conducted and physical quantities, which can be the cause of the fault, are classified according to the component and function. Also, the measuring factors for the monitoring are derived and a decision making theory is suggested. On the basis of the results, we propose a new turnout diagnostic system that can provide more driverse and precise information than the conventional system.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.35 no.2
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• pp.103-110
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• 2009

The objective of this study is to analyze the influences of fatty alcohols and fatty acids on rheological properties of oil in water (O/W) emulsions using viscosity and rheograms. As the chain length of fatty alcohols and fatty acids lengthened, the viscosity of emulsions was increased. The influence of fatty alcohols on viscosity enhancement was stronger than that of fatty acids. Both stearyl alcohol and cetearyl alcohol, which have carbon chain length similar to lipophilic portion of surfactant used in emulsion preparation, had showed the best increase in viscosity of O/W emulsions. O/W emulsions prepared with fatty alcohols and fatty acids were pseudo-plastic fluid and they showed shear thinning behaviour like as the common cosmetic emulsions. O/W emulsions prepared with cetyl alcohol, cetearyl alcohol and stearyl alcohol were thixotropic fluids and thixotropy increased with an increase in the concentration of fatty alcohols and fatty acids. Also O/W emulsions prepared with fatty alcohols were more thixotropic than those prepared with fatty acids. For the sake of viscosity increase related to O/W emulsions stability and spreadability enhancement related to payoff, it is thought that fatty alcohols are more useful than fatty acids in the O/W emulsions as the emulsion stabilizer.

• Proceedings of the KOR-BRONCHOESO Conference
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• 1977.06a
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• pp.6.1-6
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• 1977

Among the various audiometric test batteries, pure tone and speech audiometry was carried as routine. During the past 20 years, there have been works on speech word list for Korean language. As a preliminary work for standardization of Korean speech word list, the authors are intended to study on the factors of test methods with these proposal speech word lists. Now, authors has studied as followings methods and materials and the results were obtained as followings. A. Materials and Methods a. Word List 1. Paik Chun Kee (Paik) 2. Soh Jin Myoung (Soh) 3. Cynn Kyu Shik (Cynn) 4. Lee Jong Dam (Lee) 5. Hahm Tae Young (Hahm) b. Test Method 1. ascending 2. descending c. Test Material 1. live voice 2. Recorded male voice 3. Recorded female voice B. Results 1. Score of ascending method was better result than descending method. 2. Speech reception threshold and discrimination score were better in recorded female voice, live voice and recorded male voice in that order. 3. Speech reception thresholds among tested word lists were Hahm, Lee, Soh, Cynn and Paik in that order. 4. Discrimination score was highest with Cynn and Lee, Soh, Hahm, Paik in that order.

• Food Science and Preservation
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• v.14 no.6
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• pp.598-604
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• 2007

Process development and standardization are necessary in maintaining high hygienicquality of side dishes. Seasoned perilla leaves are a typical side dish needing process development. In this study the optimum condition for preparing seasoned perilla leaves was investigated experimentally. The best sensory quality was established by response surface methodology. The rinsing and washing method of preparing fresh perilla leaves was optimized to decontaminate the raw material and preserve the product in chilled storage. Washing and rising with 3% salt water reduced the aerobic bacterial count of perilla leaves to 0.55 (log CFU/g), while rinsing reduced the load from 8.08 to 4.27 (log CFU/g). The effect of rinsing method was maintained during subsequent storage of the prepared seasoned leaves at $10^{\circ}C$. There was no significant quality change in the product during chilled storage at $10^{\circ}C$. Soaking in 3% salt water for 1 min, followed by rinsing with tap water, contributed positively to the microbial quality, and is proposed as the optimal preparation method.

• Food Science and Preservation
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• v.21 no.4
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• pp.565-572
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• 2014

This study was conducted to examine the antioxidant activities of extracts derived with different extraction methods (HE, hot water extraction; UE, ultrasonic extraction; and PE, pressured extraction) from Phellinuslinteus mycelium in Mori ramulus. The extraction yield of PE (7.73%) was higher than that of UE (6.03%) and of HE (5.44%). The total phenolic and flavonoid contents of PE were 9.87 g/100 g and 1.90 g/100 g, respectively. The oxygen radical absorbance capacity (ORAC) of PE ($769.63{\mu}M/g$ FW) was higher than that of HE ($622.96{\mu}M/g$ FW) and of UE ($249.06{\mu}M/g$ FW). The DPPH and ABTS radical scavenging activities of PE at $1,000{\mu}g/mL$ were 35.85% and 51.42%, respectively. The superoxide radical scavenging activity of PE, 29.16-93.89%, was higher than that of other extracts. The ferric-reducing antioxidant power and the reducing power of PE were $180.60-607.93{\mu}M$ and 0.14-0.51, respectively. The tyrosinase inhibition activity of PE (9.66-24.05%) improved with an increase in the treatment concentration. The antioxidant and tyrosinase inhibition activities of PE were significantly higher than those of the other extracts. In conclusion, we provided experimental evidence that Phellinus linteus mycelium extracts from Mori ramulus have potential as functional materials.

• Food Science and Preservation
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• v.20 no.1
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• pp.37-44
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• 2013

To investigate the usability of the bitterns produced during salt manufacture, the characteristics of soybean curds coagulated with bitterns like solar salt bitterns (SSB), dehydrated salt bitterns (DSB), concentrated sea water (CSW) and bitterns produced during the storage of solar salt (BSS) were measured. The Mg contents of all the bitterns were the same, but the Na content of the BSS was 1.0-2.0 times as high as that of the other bitterns. The yield of the soybean curds did not differ with the addition of coagulants, except for the CSW. However, the soybean curds were acquired in large quantities by the DSB and CSW. The mg and Na contents of the soybean curds that were made with the bitterns were higher than those of $MgCl_2$. The heavy metals were below 3 ppm in the curds, especially those produced by the CSW, but Pb was not detected. Among the mechanical characteristics of the soybean curds, their adhesiveness was not affected by the coagulants, but the mechanical hardness of the curds produced by the DSB and CSW was lower. The sensory evaluation showed that the curds that were produced by the bitterns were more highly preferred than those produced by $MgCl_2$. In particular, the soybean curd that was made with the CSW was favored due to its soft texture. The results of this study, particularly the high yield of the curds that showed a soft texture, showed that the bitterns, especially the CSW, could be used safely and economically.

• Spatial Information Research
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• v.17 no.3
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• pp.361-370
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• 2009

As the increasing interests of spatial information for different application area such as disaster management, there are many researches and development of indoor spatial data models and real-time evacuation management systems. The application requires to determine and optical paths in emergency situation, to support evacuees and rescuers. The optimal path in this study is defined to guide rescuers, So, the path is from entrance to the disaster site (room), not from rooms to entrances in the building. In this study, we propose a time-dependent optimal routing algorithm to develop real-time evacuation systems. The network data that represents navigable spaces in building is used for routing the optimal path. Associated information about environment (for example, number of evacuees or rescuers, capacity of hallways and rooms, type of rooms and so on) is assigned to nodes and edges in the network. The time-dependent optimal path is defined after concerning environmental information on the positions of evacuees (for avoiding places jammed with evacuees) and rescuer at each time slot. To detect the positions of human beings in a building per time period, we use the results of evacuation simulation system to identify the movement patterns of human beings in the emergency situation. We use the simulation data of five or ten seconds time interval, to determine the optimal route for rescuers.

• International Commerce and Information Review
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• v.15 no.1
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• pp.227-256
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• 2013

Existing multinational subsidiary typologies seem to have limitations in two respects. First, the prevalence of subsidiary classification along two-dimensions fails to capture many distinct subsidiary types. Failure to reflect a sufficient richness in dimensionality can give rise to a partial picture of subsidiary typologies in the international business literature. A new typology developed from multi-dimensional approach will be required for reflecting various subsidiary roles in the multinational enterprise. Second, multinational subsidiary performing a number of activities is hard to be defined functionally across the value chain activities. In addition, multinational subsidiary roles can vary dramatically. In conclusion, despite a growing amount of work on subsidiary typologies, there seems to be limited convergence of results. the study regarding subsidiary roles still remain a challenge. In this respect, the purpose of this study is to develop a new typology based on multi-dimensional approach in order to overcome the limitations of traditional typologies. To classify subsidiary types, we propose 8 types of multinational subsidiary according to three dimensions that are adopted: (1) number of required value chain activities (2) subsidiary's sourcing capability and autonomy (3) global orientation (3) The case study analyzing Korean foreign subsidiaries appropriate for 8 types is performed to establish the validity of this study.