• Journal of Broadcast Engineering
• /
• v.12 no.2
• /
• pp.148-158
• /
• 2007

Recently, IEEE 802.15.4a(low-rate UWB) technique has been paid much attention to the LR-UWB communication system for WPAN. However, there are various interferences such as MPI(Multi Path Interference) or IPI(Inter Piconet Interference) in IEEE 802.15.4a wireless channel. In order to cancel various interferences occurred to WPAN environment, in this paper, we propose a UWB wireless communication system with high QoS(Quality of Service) which is a chaotic-OOK(On-Off Keying) system using unipolar ZCD(Zero Correlation Duration) spreading code in physical layer level. Furthermore, we analyze its performance via simulations and verify the availability of proposed system with prototype implementation.

• Microbiology and Biotechnology Letters
• /
• v.43 no.2
• /
• pp.150-157
• /
• 2015

This study was intended to evaluate the anti-atopic effect of Sargassum fulvellum water extract (SFWE). Atopic dermatitis (AD) was induced in BALB/c mice by spreading 2,4-dinitrochlorobenzene (DNCB) to the dorsal skin area. The production of IL-4 and total IgE of the SFWE treated group was significantly less than the DNCB only group. On the other hand, the production of the IFN-γ of SFWE treated group was greater than that of the DNCB only group. In addition, SFWE alleviated the AD symptoms when compared to the DNCB only group and reduced the epidermal thickness and the number of mast cells in histological analysis. In conclusion, these results suggest that the application of SFWE has an anti-atopic activity through the modulation of IL-4 and IFN-γ cytokines, and the total IgE in DNCB-induced BALB/c mice. Therefore, SFWE can be utilized with atopic disease therapies.

• Korean Security Journal
• /
• no.9
• /
• pp.27-68
• /
• 2005

Recently, because credit card crime using a personal credit information is increasing, professionalizing, and spreading the area, the loss occurring from credit card crime is enormous and is difficult to arrest and punish the criminals. At past, crime from forging and counterfeiting the credit card was originated by minority criminals, but at present, the types and appearance of credit card crime is very different to contrasting past crime. The numbers of people using credit card in the middle of 1990's was increasing and barometer of living conditions was evaluated by the number having credit card, therefore this bad phenomenon occurring from credit card crime was affected by abnormal consumption patterns. There is no need emphasizing the importance of personal credit card in this credit society. so, because credit card crime using personal credit card information has a bad effect, and brings the economic loss and harms to individuals, credit card company, and members joining credit card. Credit card crime using personal credit card information means the conduct using another people's credit card information(card number, expiring duration, secret number) that detected by unlawful means. And crime using dishonest means from another people's credit information is called a crime profiting money-making and a crime lending an illegal advance by making false documents. A findings on countermeasures of this study are as follows: Firstly, Diverting user's mind, improving the art of printing, and legitimating password from payment gateway was suggested. Secondly, Complementing input of password, disseminating the system of key-board protection, and promoting legitimations of immediate notification duty was suggested. Thirdly, Certificating the electronic certificates as a personal certificates, assuring the recognition by sense organ of organism, and lessening the ratio of crime occurrence, and restricting the ratio of the credit card crime was suggested.

• Journal of Korea Soil Environment Society
• /
• v.2 no.1
• /
• pp.21-34
• /
• 1997

Retention ponds have been dug along some of the motorways in France to minimize environmental pollution by preventing pollutants from spreading over the surrounding area. A series of studies have been conducted to determine the physicochemical characteristics of the particles settling down in such a pond to evaluate the effectiveness of the pond as a trap for heavy metals such as Pb, Zn and Cd. The highly contaminated roadside soil and the uncontaminated background soil were also studied for comparison. The settling particles exhibited heavy metal concentrations of 2 to 8 times as much as the background Sologne soil, depending on the metal species. However, the heavy metal concentrations in the roadside soil were 7 to 26 times higher than those in the· settling particles. Sequential extraction experiments illustrated that the highly contaminated roadside soil consisted mainly of the readily soluble fractions (FII, FIII and FIV) for all three heavy metals, but little W which is hardly soluble. The proportion of W considerably increased up to one third of the total in the settling particles for Pb and Zn. This result as well as the large concentration differences between the roadside soil and the settling particles indicates that most of the heavy metals were lost to the surroundings even before reaching the retention pond. Cd exhibited somewhat different behavior in that the most soluble FI, which is negligible for Pb and Zn, occupied as much as one fourth of the total in the roadside soil. In addition, FV for Cd did not increase in the settling particles.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.47 no.6
• /
• pp.129-138
• /
• 2019

'Private Garden', is a legal concept that encourages the opening of private gardens to the public. Twenty-five private gardens have registered with the Forest Service since the 2015 policy was enacted. Although it is a positive system in terms of spreading and encouraging garden culture, the exact nature, role, and designation requirements have not been fully discussed. The purpose of this study is to analyze the characteristics of 25 private gardens in Korea. The results of the study noted that the southern region occupied a large part of the geographical distribution of the private gardens, which is due to the natural and climatic conditions, the policies of the local governments, and the discretion of public officials. In addition, the gardens are almost all made up of modern gardens; there was only one house garden from the Joseon Dynasty. The owners of the gardens range from their 50s to 80s in age. The gardens were started because the owner believed it was a good endeavor, but many owners felt that it was difficult to manage the enlarged garden and eventually opened it through as a Private Garden in anticipation of receiving economic support. There are also owners who are willing to revitalize the area. In addition, profits are generated from facilities other than the gardens, and some operate related programs to promote the culture of gardening. For a sustainable Private Garden system, it is necessary to check the registration criteria and establish a clear role in the region. There is also a need for further measures for management and marketing. This study is meaningful as basic research on the Private Garden system that is not yet systematic.

• Korean journal of applied entomology
• /
• v.59 no.1
• /
• pp.41-54
• /
• 2020

Two mosquito species were collected in still-water near farming area in Andong, Korea. Based on morphological characters, these two mosquitoes were identified as Aedes koreicus and Culex vagans, respectively. DNA barcode analyses supported the identification. An entomopathogenic bacterium, Bacillus thuringiensis subsp. israelensis (BtI), exhibited insecticidal activities against the two mosquito species and its virulence was more potent than that of B. thuringiensis subsp. kurstaki. It has been known that the bacterial metabolites of Xenorhabdus spp. suppress insect immunity and enhance pathogenicity of B. thuringiensis. This study tested the effect of the bacterial culture broth of Xenorhabdus spp. on enhancing BtI pathogenicity. Among three Xenorhabdus spp., culture broth of X. ehlersii (Xe) was relatively effective to enhance BtI pathogenicity against both mosquito species. Indeed, organic extracts of Xe culture broth suppressed the hemocyte-spreading behavior, suggesting the presence of immunosuppressant in the culture broth. These results suggest a formulation of BtPlus by mixing BtI spore and Xe culture broth to be applied to control the two mosquito species.

• The Journal of Fisheries Business Administration
• /
• v.18 no.1
• /
• pp.37-57
• /
• 1987

This article discussed the characteristics of several Pareto-optimal incentive contracts between owner and labor, more specifically, four situations: reporting output jointly observable by labor ana owner; reporting both output and effort; incorporating other endogenous elements (like capital) that affect the production process and Pareto-optimal fee schedules; and ascertaining the effects of private pre-decision information private- decision information, and per-contact informational asymmetries. Also presented were several extensions of the basic contractual model, and the different components of agency costs associated with labor-owner contractual relations. In a single-period model, the agency problem exists because the uncertainty prevents the owner from using the cash flow to determine unambiguously the labor's action. Holmstrom(1979) suggests that "when the same situation repeats itself over time, the effects of uncertainty tend to be reduced and dystunctional behavior is more accurately revealed, thus alleviating the problem of moral hazard. " Under these conditions, if the labor selects the first-best level of effect in each period, the cash flow will be independent and identically distributed over time. As the number of periods increases, the variance of the labows average output, if he selects the first-best level of effort in each period, gets smaller. Note that for this diversification effect to occur, it is necessary that the owner evaluate the labor's effort over the entire history of his employment, rather than evaluate each period's performance separately. Radner(1980) and Rubinstein and Yaari(1980) consider the extreme case in which there are an infinite number of observations. They show that the owner can eventually detect and systematic shirking on the part of the labor by comparing the labor's average output with what would be expected if the labor had been selecting the first-best level of effort in each period. In a dynamic model with incentive problems we have demonstrated that the labor's second-period compensation will depend on his first-period performance. This allows the owner to diversify away some of the uncertainty surrounding the labor's actions. In addition, this allows the owner to smooth the labor's income over time by spreading the risk of the first-period outcome over both periods. At least some unexplored avenves in this area invite future accounting research: situations where owner has different incompatible objectives and negotiates a contract with labor; circumstances in which owner deals with multiple objectives and negotiates contracts with several labors simultaneously; the value of costly accounting information systems and communication in establishing, Pareto-optimal incentive contracts, and the value and effects of inside information, Thorough theoretical or empirical research on each of these topics not only would increase our knowledge about the role and significance of accounting information but could also provide explanations of the inherent differences among various organizations and in their economic behavior. behavior.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.44 no.5
• /
• pp.212-219
• /
• 2018

Objectives: The objective of this study was to analyze 11 cases of subcutaneous emphysema associated with dental procedures from a single hospital and discuss approaches for accurate diagnosis and treatment of the condition. Materials and Methods: The medical records of 11 patients who were treated for subcutaneous emphysema related to dental procedures between January 2009 and April 2017 were analyzed retrospectively. Patients with subcutaneous emphysema within the facial area or that spread to the neck and beyond, including the facial region, were assigned to two groups and compared in terms of age, sex, and durations of antibiotic use, hospitalization, and follow-up until improvement. The correlation between location of the origin tooth and range of emphysema spread was analyzed. Results: The average durations of antibiotic use during conservative treatment and follow-up until improvement were 8.55 days (standard deviation [SD], 4.46 days) and 1.82 weeks (SD, 1.19 weeks), respectively. There was no intergroup difference in duration of antibiotic use (P=0.329) or followup (P=0.931). Subcutaneous emphysema was more common after dental procedures involving the maxilla or posterior region than after those involving the mandible or anterior region. There was no significant difference in air distribution according to location of the air orifice (maxilla, mandible, or both; P=0.106). Conclusion: Upon adequate conservative treatment accompanied by prophylactic antibiotic treatment considering the risk of infection, patients showed signs of improvement within a few days or weeks. There was no significant difference in treatment period between patients with subcutaneous emphysema localized to the facial region and those with subcutaneous emphysema spreading to the neck or beyond. These findings need to be confirmed by analysis of additional cases.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.39 no.7
• /
• pp.567-578
• /
• 2015

Single droplet-wall collision heat transfer characteristics on a heated plate above Leidenfrost temperature were experimentally investigated considering the effects of impact velocity. The collision characteristics of the droplet impinged on the heated wall and the changes in temperature distribution were simultaneously measured using synchronized high-speed video and infrared cameras. The surface heat flux distribution was obtained by solving the three-dimensional transient heat conduction equation for the heated substrate using the measured surface temperature data as the boundary condition for the collision surface. As the normal impact velocity increased, heat transfer effectiveness increased because of an increase in the maximum spreading diameter and a decrease in the vapor film thickness between the droplet and heated wall. For We < 30, droplets stably rebounded from a heated wall without breakup. However, the droplets broke up into small droplets for We > 30. The tendency of the heat transfer to increase with increasing impact velocity was degraded by the transition from the rebounding region to the breakup region; this was resulted from the reduction in the effective heat transfer area enlargement due to the breakup phenomenon.

• Journal of Science and Technology Studies
• /
• v.18 no.1
• /
• pp.219-265
• /
• 2018

Recently, interest in energy tranisition is rising. Energy transition requires active participation and cooperation of diverse stakeholders, including users / citizens, in that it requires not only changes in technological factors but also changes and coordination of various social factors. Living labs are attracting attention as one of the ways to do this. This article is a detailed analysis of the activities of the mini-PV living lab in the urban area from 2016 to 2017 at the Seoul, Sung Dae Goal. Through the Living Lab, mini PV DIY products, backup centers, local financial services, and the development of a variety of education and training strategies have been achieved. These activities and achievements were analyzed through questions raised on strategic, tactical, and operational levels, as well as through multi-level perspective and interaction between initiative, regime, and niche. In conclusion, this living lab activity confirmed the possibility of a 'transition lap' to solve social problems such as sustainability of energy production and utilization. In particular, it gained remarkable results in terms of the operational leves of transition management governance, that is, transition experiment, and it was also remarkable in that it was the initiative of citizens. However, it did not proceed without difficulty. In particular, structural problems such as the conflict between the flexibility inherent in living lab and the bureaucratic rigidity of the financial support organization have appeared. There was also a limitation that there was no 'transition field' on the strategic level necessary to replicate and expand strategic niches while spreading the knowledge gained from the transition experiment, forming the vision of transition.