• 한국IT서비스학회지
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• 제15권2호
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• pp.35-49
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• 2016

With the gradual development of IT technology, voice phishing victims are increasing in number. In the past when only voice phone calls were made, personal information or financial information were stolen mainly by a direct phone call, but recently, as smart phones are widely in use, it is evolving into a way such as smishing that leads an access to a site with malicious codes spreading out. Since it is easy to run away after committing a crime, and trace are rarely left in case of voice phishing, it is difficult to find out criminal. In addition, it is most likely that a victim be would be exposed to further damage from another voice phishing. Its technique is growing in kinds and turning more intelligent day by day; Therefore, its victims are increasing in number. Previous researches mainly focused the area of legal studies while the factors exposed to voice phishing have not been made. Therefore, this study has analyzed the motifs in which voice phishing is done to draw out its outcomes as follows. First, a victim comes to trust the criminal by the factors of favorability, rare message, and mutuality. Second, the more sophisticated the technique of a criminal, the more likely a victim is exposed to voice phishing.

• E2M - 전기 전자와 첨단 소재
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• 제11권10호
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• pp.60-65
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• 1998

Deposition conditions, surface morphology, and electrical properties of polyamic acid alkylamine salts (PAAS) Langmuir-Blodgett(LB) films have been investigated through a study of surface pressure-area $\pi$-A isotherms, AFM (atomic force microscopy), and current-voltage characteristics. To obtain the optimum conditions of film deposition, the $\pi$-A isotherms were examined by varying temperature, barrier moving speed, dipping speed, spreading amount of solution etc. The Z-type LB films were made at the surface pressure of 5 mN m-1 and 25 mN m-1 for the AFM study; the former surface pressure forms the gas phase and the latter one forms the solid phase. The LB film made in the gas phase show domains with a size of about 200 A diameter and 70 A height. However, the LB films made in the solid phase show a very smooth surface with 2 A surface roughness. In the current-voltage characteristics measured along the perpendicular direction of the films, ohmic conduction has been observed below 105 V cm-1 and the calculated electrical conductivity is about 10-13 S cm-1. Nonohmic conduction has been observed above = 10-11 V cm and the conduction mechanism can be explained by the Schottky effect.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.1491-1498
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• 2003

Droplet evaporation can be used to transfer large amounts of energy since heat is transferred across a thin liquid film. Spreading the drop over a larger area can enhance this heat transfer. One method of accomplishing this is to dissolve gas into the liquid. When the drop strikes the surface, a gas bubble nucleates and can grow and merge within the liquid, resulting in an increase in the droplet diameter. In this study, time and space resolved heat transfer characteristics for a single droplet striking a heated surface were experimentally investigated. The local wall heat flux and temperature measurements were provided by a novel experimental technique in which 96 individually controlled heaters were used to map the heat transfer coefficient contour on the surface. A high-speed digital video camera was used to simultaneously record images of the drop from below. The measurements to date indicate that significantly smaller droplet evaporation times can be achieved. The splat diameter was observed to increase with time just after the initial transient dies out due to the growth of the bubble, in contrast to a monotonically decreasing splat diameter for the case of no bubbles. Bursting of the bubble corresponded to a sudden decrease in droplet heat transfer.

• 한국전산유체공학회지
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• 제20권1호
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• pp.10-15
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• 2015

In this study, the characteristics of water treatment mixer with various propeller profiles are numerically invesitgated. The computation was conducted by solving the incompressible Navier-Stokes equations on unstructured tetrahedral elements with k-${\varepsilon}$ turbulence model. It was found that the spreading angle and swirl magnitude of the jet are important factors for the mixer efficiency, since they clearly characterize the propeller and the frontal surface area of the propeller but not so much affected by the skew angle if it exceeds 30 degrees. The case1 and case2 models are found to show the best propeller efficiency. The case2 with low blade angle, however, requires the lowest power input for the same discharge capacity as the case1.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.261-261
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• 2017

This study was carried out to provide basic data for spreading rice direct seeding by inducing stabilization of seedlings, yield and quality according to sowing times in rice direct seeding cultivation. In 2016, 'Sukwang' was seeded 3 times by 10 days interval on May. 10, 20, 30 and 6kg/10ha of seeding rate respectively in Iksan. In summary, the number of rice seedling establishment was higher than the optimum seedling establishment level at all sowing periods and the seeding rate was better as the sowing period was delayed. Weed development by sowing was the highest at early sowing, May 10, and decreased at late sowing. Heading dates were delayed by 3days for sowing on May 10, 7days for sowing on May 20, and 11 days on sowing on May 30. Rice yield increased with the delay sowing time and compared to the transplanting. It was 84% in sowing on May 10, 94% in sowing on May 20, and 99% in sowing on May 30. In addition, head rice ratio and head rice yield increased according to delayed of seedling.

• 한국전자파학회논문지
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• 제12권5호
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• pp.740-746
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• 2001

1994년부터 국내 남해안지역에서 상용서비스되고 있는 TRS(Trunked Radio System)서비스에 빈번히 간섭이 발생되고 있는데, 그 원인은 일본해안에서 발사되는 이동전화 신호의 덕팅(ducting)전파에 의한 것으로 한.일간 합동조사에 의해 분석되었다. 이와 같은 인접국가 간의 간섭문제는 일본뿐만 아니라 중국 등 이동통신이 활성화되면 여러 주파수 대역에서 발생할 가능성이 커지면서 한.중 이동 서비스간의 간섭문제가 계속 대두될 것이다. 따라서 본 논문에서는 중국으로부터 들어오는 전파간섭 문제를 해결하기 위한 기초 연구로서 수행한 중국으로부터의 간섭전파 측정 및 분석 방법을 제시하고, 분석결과를 요약하였다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권5호
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• pp.2201-2204
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• 2014

Russian rates for melanoma incidence and mortality are relatively low as compared to some other white populations but the tumor is of increasing importance. In this paper, data are based on a retrospective descriptive analysis of melanoma epidemiology and clinicopathological characteristics in Krasnoyarsk Territory belonging to the Siberian Federal District of the Russian Federation. The age-adjusted incidence and mortality rates for the period 1996-2009 were determined with subsequent retrospective analysis of clinicopathological data of 103 primary melanoma cases. Our results showed that incidence and mortality rates in the region under consideration match the Russian national trends and correspond to epidemiological data of the countries of Eastern Europe. Stratification of melanoma cases by age, sex, clinicopathological state and localization revealed a prevalence of lesions on the trunk and lower extremities. Most melanomas diagnosed were of superficial spreading type and the third Clark's level of tumor invasion and stage II according to AJCC. In spite of comparatively low rates of incidence and mortality the trend to increase of melanoma cases in the region under consideration obviously calls for more attention and further investigation.

• 대한기계학회논문집A
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• 제29권9호
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• pp.1169-1174
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• 2005

Imprint lithography is a promising method for high-resolution and high-throughput lithography using low-cost equipment. In particular, ultraviolet-nanoimprint lithography (UV-NIL) is applicable to large area imprint easily. We have proposed a new UV-NIL process using an elementwise patterned stamp (EPS), which consists of a number of elements, each of which is separated by channel. Experiments on UV-NIL are performed on an EVG620-NIL using the EPS with 3mm channel width. The replication of uniform sub 70 nm lines using the EPS is demonstrated. We investigate the nonuniformity of residual layer caused by wafer deformation in experiment with varying wafer thickness. Severely deformed wafer works as an obstacle in spreading of dropped resin, which causes nonuniformity of thickness of residual layer. Numerical simulations are conducted to analyze aforementioned phenomenon. Wafer deformation in the process is simulated by using a simplified model, which is a good agreement with experiments.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2004년도 춘계 종합학술대회 논문집
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• pp.217-223
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• 2004

거래내역의 투명성 향상을 위한 기초 자료로 사용되는 전표데이터의 구조를 분석하여 전표 XML Schema를 설계하고, 기업회계의 공통적인 전표처리 기능을 전표데이터베이스와 연동되는 기업 회계와 관련된 다양한 분산 애플리케이션에서 이용할 수 있게 하는, 전표데이터의 표준화와 전표처리 서비스의 정형화 모델을 제시한다. 본 논문의 결과는 전자 상거래에 필요한 회계처리 시스템의 표준화, 웹 서비스에 의한 공통 전표처리기능의 간편한 재사용, 웹 서비스의 접근용이성을 이용한 기업 간 상호 연동성을 지원하는 표준화의 확산으로 분산 애플리케이션의 효율적인 개발에 기여할 것이다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 춘계학술대회논문집B
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• pp.520-524
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• 2000

A ejector system is one of the fluid machinery, which has been mainly used as an exhaust pump or a vacuum pump. The ejector system has often been pointed out to have only a limited efficiency because it is driven by pure shear action and the mixing action between primary and secondary streams. In the present work, numerical simulations were conducted to investigate the effects of the geometry and the mass flow ratio of supersonic ejector-diffuser systems on their mixing performance. A fully implicit finite volume scheme was applied to solve the axisymmetric Navier-Stokes equations, and the standard ${\kappa}-{\varepsilon}$ turbulence model was used to close the governing equations. The flow fields of the supersonic ejector-diffuser systems were investigated by changing the ejector throat area ratio and the mass flow ratio. The existence of the second throat strongly affected the shock wave structure inside the mixing tube as well as the spreading of the under-expanded jet discharging from the primary nozzle, and served to enhance the mixing performance.