• 한국HCI학회:학술대회논문집
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• 한국HCI학회 2006년도 학술대회 1부
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• pp.954-959
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• 2006

Virtual Reality simulation enables immersive 3D experience of a Virtual Environment. A simulation-based VE can be used to map real world phenomena into virtual experience. This research studies on the use of Newton's physics law to demonstrate the effects of forces upon object's falling movement, and their effects towards other fallible objects. A reconfigurable simulation enables users to reconfigure the parameters of the objects involved in the simulation, so that they can see different effects from the different configurations, such as force magnitude and distance between objects. This concept is suitable for a classroom learning of physics law. Preliminary implementation is done on a PC with a joystick for 4DOF movement. The graphics is implemented by SGI OpenGL Performer. A middleware called NAVERLib that consists of Performer's modules for easy XML-based configuration is used for management of visualization, network and devices connection, and where the engine of this domino simulation is attached.

• International Journal of Internet, Broadcasting and Communication
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• 제12권4호
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• pp.11-17
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• 2020

This paper proposed the design of a new window signage system architecture, which utilized a window of a building, with attached LED for visible light communication. In this paper, the proposed method using the LED strip to transmit light data and receive the data through a HMD with a smart device camera. The LED strip attached to the existing building window, as a part of semi-transparent signage. Semi-transparent signage based on a controllable LED strip-modules and attached to the window used to provide entertainment contents and the information service to people through optical camera communication (OCC) as well. Also, this work suggests using the camera supplied Head Mounted Device (HMD) as an OCC receiver. The LED attached window signage system structure described in this paper can be utilized in various buildings infrastructure like house, shopping areas, industrial building, etc.

• 대한환경공학회지
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• 제29권7호
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• pp.833-838
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• 2007

본 연구에서는 양전하를 띤 여재 입자에서 박테리아의 부착 및 이동에 관한 연구를 위하여 회분 및 칼럼실험을 수행하였다. 본 실험에 사용된 박테리아는 E. coli ATCC 11105(길이: 2.2 ${\mu}m$ 직경: 0.6 ${\mu}m$)이었고, 여재는 석영모래(입경분포: 0.5-2.0 mm, 평균 입경: 1.0 mm)와 철코팅 모래이었다. 회분실험결과에 의하면 철코팅 함량이 증가함에 따라, 박테리아의 부착량이 증가하는 것으로 나타났다. 철코팅 모래의 함량 0%(석영모래 100%)에서는 약 46% 정도의 박테리아가 부착되었고, 철코팅 모래의 함량 100%(석영모래 0%)에서는 약 97% 정도의 박테리아가 부착되었다. 칼럼실험결과 또한 철코팅 함량이 증가함에 따라, 박테리아의 부착량이 증가하는 것을 보여주고 있다. 철코팅 모래의 함량이 0에서 100%로 증가함에 따라 박테리아의 부착량이 8에서 94%로 증가하였다. 본 연구의 실험결과를 통해 양전하를 띤 여재 입자가 박테리아의 이동에 영향을 미칠 수 있음을 알 수 있다.

• 정보보호학회논문지
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• 제27권4호
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• pp.753-761
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• 2017

최근 각 분야에서 외장형 USB 매체를 활용한 악성코드 감염 및 비밀문건의 유출 사고가 빈번하게 발생하고 있다. 외장형 USB 매체를 이용해서 발생한 사건들을 조사하기 위해서 매체들에 대한 수사를 진행하지만, 분실 및 훼손이 발생할 수 있다는 점에서 많은 어려움이 있다. 결국 외장형 USB 매체에 대한 사건 조사를 위해서는 외장형 USB 매체뿐만 아니라 해당 매체가 연결되었던 시스템에 대한 직접적인 분석을 진행해야만 한다. 본 논문은 외장형 USB 매체가 연결되었던 Windows 시스템의 아티팩트에 대한 분석으로 매체에서의 작업이력을 점검하는 방법을 제안한다. 이를 통해 외장형 USB 매체를 확보하지 못한 상황에서도 시스템에서 USB 매체를 통해서 수행되었던 작업이력을 분석하는데 활용될 수 있을 것으로 기대된다.

• 아동학회지
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• 제29권1호
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• pp.305-324
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• 2008

This study investigated conditions and teachers' perceptions of the Christian preschool curriculum in Korea. Participants were 119 teachers in Christian preschools(84 teachers in preschools attached to churches and 35 teachers in non-attached Christian preschools). They responded to a questionnaire developed for the study. Most of the Christian preschools used appropriate educational aims clearly reflecting a Christian world view and the purpose of Christian education. However, teaching methods and instructional media were limited. Type of educational institution, academic background, and years of teaching in Christian institutions affected the results.

• 환경위생공학
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• 제14권4호
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• pp.172-179
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• 1999

In this research, biological treatability test was conduced using seawater flocculated tannery wastewater by fixed biofilm reactor. During one cycle, the removal efficiency of organic corbon obtained with fixed biofilm process for treating tannery wastewater was considerably greater than that with activated sludge process. As the hydraulic retention time increased form 0.5day to 4day, removal efficiency of organic carbon was increased from 72% to 87.3%. Attached biomass in media increased with influent organic loading up to 29g MLSS/L, that could reduce the specific organic loading rate. The continual measurement of attached biomass was possible for the operation of the biofilm reactor. Equal and low nitrication rates were observed in both suspended growth activated sludge process and fixed biofilm process, despite commercial nitrifier was seeded. Through the process of treating the tannery wastewater, EC50 values which is measured by the use of Ceriopdaphnia dubia, were decreased to the extent of 50% after treatment of seawater flocculation and of 83% after biological treatment, respectively, compared to those of the untreated wastewater.

• Bulletin of the Korean Chemical Society
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• 제32권2호
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• pp.664-672
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• 2011

A series of hydrophilic chromophores was synthesized through introduction of dendritic sulfonate anions using click chemistry. A dendron structure bearing several sulfonate groups enhances hydrophilicity of attached chromophores. A click triazole formation connects chromophores with hydrophilic groups. A neutral trichloroethyl sulfonate has versatile features such as easy introduction, chemical endurance for isolation or storage, and convenient transformation to a hydrophilic anion. Zinc and OH mediated cleavage of trichloroethyl group from the neutral sulfonate undergoes to generate a water-soluble sulfonate anion. The solubility was examined with different counter cations and in different pH media and thus increased with the number of attached sulfonate ion. Two hydrophilic chromophores of stilbene-derived and azobenzene-derived dipolar structures exhibit clear negative and positive solvatochromism in protic solvents, respectively.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2013년도 춘계학술대회
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• pp.249-252
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• 2013

The recent cyber attacks paralyzed several major banking services, broadcasters, and affected the services of a telecommunications provider. Media outlets classified the attack as cyber terror and named it an Advanced Persistant Threat. Although the attack significantly disrupted these services for at least one day, various components used in the attack were not new. Previous major cyber attacks towards targets in South Korea employed more advanced techniques thus causing greater damage. This paper studies the anatomy of the recent 2013.3.20 attack, studies the technical sophistication of the malware and attack vectors used compared with previous attacks.

• 한국환경보건학회지
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• 제15권1호
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• pp.89-96
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• 1989

An aerated submerged biofilm reactor is the reactor in which influent organic substrates are aerobically oxidized by suspended biomass and attached biomass of biofilm grown on the surface of submerged media. The objective of this study was to investigate the effect of aeration intensity on microbial characteristics and treatment efficiency in submerged biofilm process. In the organic loading rate (4.3kg BOD/$m^{3} \cdot day$), biofilm thickness (420-780$\mu$m) and attached biomass(1.79-2.94mg/cm$^{2}$) increased as the aeration intensity increased (2-8m$^{3}$ air/$m^{2} \cdot hr$), but biofilm density decreased (42.25-37.69mg/cm$^{3}$). The minimum aeration intensity for prevention of deposited biomass was 2m$^{3}$ air/$m^{2} \cdot hr$. The minimum dissolved oxygen of 2.5mg/l had to be maintained for improved efficiency.

• 미생물학회지
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• 제45권2호
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• pp.133-139
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• 2009

비점오염원 관리를 위하여 영양염류 농축장치를 개발하였다. 이 장치는 저농도 상태인 영양염류를 고농도로 전환시키며, 이 과정에서 세균이 중요한 역할을 하고 있다. 세균은 장치 내 여재에 생물막을 형성하면서 영양염류를 농축하였다. 총인의 농축효율을 확인하기 위해 장치로 유입되는 하천수와, 유출되는 공극수, 여재에서 총인과 용존무기인, 총세균수를 측정하였고 농축과정에서 미생물 군집이 어떻게 달라지는가를 파악하기 위해 DGGE를 수행한 후 염기서열을 분석하였다. 총인의 경우 하천수에서는 0.12~0.35 mg/L로 농도가 낮았지만 농축 후 유출수에서는 0.45~0.86 mg/L, 여재에서는 40.91~242.71 mg/kg로 매우 높았다. 그러나 용존무기인은 농축이 일어나지 않았다. 총세균수 역시 하천수에서는 $0.3\sim2.3\times10^6$ cells/ml이었으나 농축 후 유출수와 여재에서 각각 $0.4\sim4.4\times10^6$ cells/ml, $0.8\sim1.9\times10^9$ cells/g로 높게 나타났으며, 총인의 농도 변화와 비슷한 패턴을 보여 총인의 농도와 세균수 간에 밀접한 관계가 있음을 확인하였다. 또한 세균의 군집은 하천수에서는 Clostridium 속이 주로 나타났으나 여재에서는 Aquabacterium 속이 우점하다가 천이가 일어나서 Clostridium 속과 Enterococcus 속이 출현하였다. 결론적으로, 영양염류 농축장치의 여재에서 부착세균의 생장으로 인하여 총인의 농축이 일어났음을 확인하였다. 따라서 이 농축장치는 총인을 고농도로 회수함으로써, 저농도로 다량 유입되는 비점오염원의 관리를 용이하게 할 수 있으며, 회수된 농축수는 수계에 추가적인 부하로 작용하지 않는 자연비료로서 활용할 수 있다.