• Title/Summary/Keyword: IT

Search Result 395,622, Processing Time 0.287 seconds

Neutralization Treatment of Acid Mine Drainage Using Ca(OH)2 (소석회를 이용한 산성광산배수 중화처리)

  • Park, Young-Goo;Park, Joon-Seok;Hong, Seong-Ju
    • Applied Chemistry for Engineering
    • /
    • v.16 no.3
    • /
    • pp.391-396
    • /
    • 2005
  • This study was conducted to neutralize acid mine drainage (AMD) of Soo and Hambaek mines, located in Kangwon-Do Korea, using $Ca(OH)_2$. When 0.295 g $Ca(OH)_2/L$(AMD) was added to the drainage in a neutralization reactor, pH of liquid in the reactor and the effluent were maintained at 9.5 and 8.4, respectively. The pH met the required effluent standard. With 10~50% of feedback of effulent sludge to the reactor, the pH of neutralized fluid in the reactor remained nearly constant, but $SO{_4}^{-2}$ concentration in the effluent increased adversely compared to the non-return sludge case. With 30% of sludge feedback, it was possible to decrease suspended solids (SS) concentration in the effluent without a problem in Fe concentration. When 100 mL of 0.1 M $BaCl_2$ was added to 1 L of AMD treated with $Ca(OH)_2$, removal efficiency of $SO{_4}^{-2}$ increased to over 90%. Aanalyses of pH, Fe, and $SO{_4}^{-2}$ showed that the optimal results were obtained when pH of neutralizatio reactor and sludge return ratio were maintained at 9.5 and 30%. This can result in possible cost reduction of 31.4% for maintenance and 29.8% for facility construction by alternating $Ca(OH)_2$ to NaOH.

Control of the CaCO3 Saturation Index Parameters for Protecting the Corrosion of Waterworks Pipe (상수도관 부식방지를 위한 탄산칼슘 포화지수(LI) 인자 제어에 관한 연구)

  • Park, Young-Bok;Kong, Sung-Ho
    • Applied Chemistry for Engineering
    • /
    • v.16 no.3
    • /
    • pp.372-378
    • /
    • 2005
  • Calcium Carbonate Saturation Index (LI: Langelier Index), an indicator of $CaCO_3(s)$ saturation, indicates corrosiveness of drinking water and it has been used to monitor drinking water conditions in USA, E.U, and Japan. The objective of this research was to measure LI parameters including water temperature, pH, total alkalinity, calcium ion concentration, and electric conductivity, and to evaluate possibility of using LI in domestic system. Results showed that water temperature varied from 2.0 to $26^{\circ}C$ during 15 months, indicating an average annual temperature of $23.9^{\circ}C$. Total alkalinity was from 20 to 45 mg/L. The concentration difference between total alkalinity and $HCO_3{^-}$ value was hardly observed; the concentration of total alkalinity can be replaced by that of $HCO_3{^-}$. Tap water had a medium corrosiveness since LI values were from 2.0 to 0.5. To reduce the corrosiveness and to increase LI values of drinking water, the results of this study showed that chemicals such as $Ca(OH)_2$, $CaCO_3$, NaOH, or $NaHCO_3$ should be added to water treatment plants.

Study of CO2 Adsorption Characteristics on Acid Treated and LiOH Impregnated Activated Carbons (산 처리 및 LiOH 첨착 활성탄에서 이산화탄소의 흡착 특성에 대한 연구)

  • Han, Jae Uk;Kim, Dae Jung;Kang, Min;Kim, Jin Won;Kim, Ji Man;Yie, Jae Eui
    • Applied Chemistry for Engineering
    • /
    • v.16 no.3
    • /
    • pp.312-316
    • /
    • 2005
  • Adsorption characteristics of $CO_2$ on activated carbons were evaluated using dynamic adsorption method in a fixed bed with acid treatment, LiOH impregnation and water vapor supply. Physical and chemical properties of the activated carbons were measured using SEM, EDS, nitrogen adsorption, FTIR and XRD. Nitric acid treatment led to the decrease in BET surface area and the increase in oxygen content of virgin activated carbon, and it produced a new functional group that included nitrogen. For the reduction of BET surface area by LiOH impregnation, the nitric acid treated activated carbon (NAC) was less than the virgin activated carbon (AC). Large particles of LiOH were present on the carbon surface when the content of LiOH was over 2 wt%. The adsorbed amount of $CO_2$ on activated carbon in a fixed bed increased with the acid treatment, LiOH impregnation and water vapor supply. The XRD results indicated that LiOH was converted to $Li_2CO_3$ after the adsorption of $CO_2$ on LiOH precursor.

Digital Camera Identification Based on Interpolation Pattern Used Lens Distortion Correction (디지털 카메라의 렌즈 왜곡 보정에 사용된 보간 패턴 추출을 통한 카메라 식별 방법)

  • Hwang, Min-Gu;Kim, Dong-Min;Har, Dong-Hwan
    • Journal of Internet Computing and Services
    • /
    • v.13 no.3
    • /
    • pp.49-59
    • /
    • 2012
  • Throughout developing digital technology, reproduction of image is growing better day by day. And at the same time, diverse image editing softwares are developed to manage images easily. In the process of editing images, those programs could delete or modify EXIF files which have the original image information; therefore images without the origin source are widely spread on the web site after editing. This matter could affect analysis of images due to the distortion of originality. Especially in the court of law, the source of evidence should be expressed clearly; therefore digital image EXIF file without deletion or distortion could not be the objective evidence. In this research, we try to trace the identification of a digital camera in order to solve digital images originality, and also we focus on lens distortion correction algorism which is used in digital image processing. Lens distortion correction uses mapping algorism, and at this moment it also uses interpolation algorism to prevent aliasing artifact and reconstruction artifact. At this point interpolation shows the similar mapping pattern; therefore we want to find out the interpolation evidence. We propose a minimum filter algorism in order to detect interpolation pattern and adjust the same minimum filter coefficient in two areas; one has interpolation and the second has no interpolation. Throughout DFT, we confirm frequency character between each area. Based on this result, we make the final detection map by using differences between two areas. In other words, thereby the area which has the interpolation caused by mapping is adjusted using minimum filter for detection algorism; the second area which has no interpolation tends to different frequency character.

A Study on the Factors Influencing the Intention of Silve Generation to Use Internet (실버세대의 인터넷 활용 영향요인 연구)

  • Kim, Mi-Ryang;Kim, Tae-Ung;Kim, Jae-Hyoun
    • Journal of Internet Computing and Services
    • /
    • v.10 no.1
    • /
    • pp.145-158
    • /
    • 2009
  • No other change in Kora has offered gredter chalenges and opportunities than the emergence of the Internet and its related Information Technology. In the technology for accessing the ever growing wave of information. The quality of the silver generation is increasingly difficult to achieve because of the complexities of life in today's ICT(Information & Comunication Technology) dependent society, Life is more interesting when one knows what is going on, what opportunities exist, and when alternatives to current practices can be discovered and utilized with ease. The purpose of this study is to identify the determinants of attitude and planned behavior toward using internent for the quality of life. This study employ the intention to use internet, perceived ease of use, perceived usefuiness, self-efficacy, stress factor, generation gap, and income as major research variables, and collected 288 survey responses from senior citizen over 55. The results indicate that the perceived usefuiness and ease of use influence the intention to use internet, and that the self-efficacy, the ease of use and generation gap has some impact on the attitude, but the stree factor and the income level do not appear significant to the attitude. It was also found that the self-efficacy and the income level determine the level of ease of use. In addition, some useful suggestions concerning the continuing education program for silver generations are presented.

  • PDF

Game Based Cooperative Negotiation among Cloud Providers in a Dynamic Collaborative Cloud Services Platform (게임 이론 기반 동적 협력 클라우드 서비스 플랫폼에서의 클라우드 공급자간 협상 기법)

  • Hassan, Mohammad Mehedi;Huh, Eui-Nam
    • Journal of Internet Computing and Services
    • /
    • v.11 no.5
    • /
    • pp.105-117
    • /
    • 2010
  • In recent years, dynamic collaboration (DC) among cloud providers (CPs) is becoming an inevitable approach for the widely use of cloud computing and to realize the greatest value of it. In our previous paper, we proposed a combinatorial auction (CA) based cloud market model called CACM that enables a DC platform among different CPs. The CACM model allows any CP to dynamically collaborate with suitable partner CPs to form a group before joining an auction and thus addresses the issue of conflicts minimization that may occur when negotiating among providers. But how to determine optimal group bidding prices, how to obtain the stability condition of the group and how to distribute the winning prices/profits among the group members in the CACM model have not been studied thoroughly. In this paper, we propose to formulate the above problems of cooperative negotiation in the CACM model as a bankruptcy game which is a special type of N-person cooperative game. The stability of the group is analyzed by using the concept of the core and the amount of allocationsto each member of the group is obtained by using Shapley value. Numerical results are presented to demonstrate the behaviors of the proposed approaches.

Geometric Distortion Compensation of Projector Image based on Equation of Straight Line (직선의 방정식을 기반으로 한 프로젝터 영상의 기하왜곡 보정)

  • Jung, Jung-Il;Cho, Jin-Soo
    • Journal of Internet Computing and Services
    • /
    • v.11 no.5
    • /
    • pp.27-35
    • /
    • 2010
  • In this paper, we propose a method that can compensate the geometric distortions of image caused from an arbitrary nonflat display surface(or wall) under the environment of portable overhead projector without a flat screen. In the proposed method, we first project a grid pattern to an arbitrary nonflat display surface and then derive an equation of straight line that represents the geometry relationship between the distorted grid pattern and the original grid pattern. Next, after determining the proper size of the original grid pattern according to the form of the display surface, we generate a compensation pattern from the derived equation of straight line, which can symmetrically compensate for the distorted image. Finally, we compensate for the geometric distortions of the projected image by segmenting the real image to be projected from portable overhead projector and prewarping it according to the compensation pattern. To evaluate the proposed method, we performed experiments of image compensation on inclined surface, bent surface and curved surface that are frequently occurred in the environment of portable overhead projector without a flat screen. From the experimental results, we found that the proposed method could be very effective in compensating for the general types of the geometric distortions of the projected images.

High Concentrated Toluene Decomposition by Non-thermal Plasma-Photocatalytic (Mn-Ti-MCM-41) Hybrid System (상온 방전 플라즈마-광촉매(Mn-Ti-MCM-41) 복합 시스템에 놓인 고농도 톨루엔의 분해성능)

  • Ban, Ji-Young;Son, Yeon-Hee;Lee, Sung-Chul;Kang, Misook;Choung, Suk-Jin;Sung, Joon-Yong
    • Applied Chemistry for Engineering
    • /
    • v.16 no.3
    • /
    • pp.413-421
    • /
    • 2005
  • This study focused on the decomposition of toluene in a plasma-photocatalytic hybrid system. Hexagonally packed meso-structured Mn-titanosilicates (Mn-Ti-MCM-41), as the photocatalysts, have been prepared by the hydrothermal method. The physical properties of the photocatalysts were characterized using XRD, XPS, TEM, BET/ICP, and $NH_3$/Toluene-TPD. Experiments were carried out at the applied voltage of 9.0 kV and at room temperature of $20^{\circ}C$. In the plasma only system, the activity of the toluene decomposition was higher than that in the photocatalytic system. However, the amount of by-products, such as phenol, $C_2{\sim}C_4$ alkene, was also increased in the plasma only system. However, the by-products decreased remarkably in a plasma-photocatalytic hybrid system. When Mn5mol%-Ti-MCM-41 was used as a photocatalyst in a plasma-photocatalytic hybrid system, the $CO_2$ selectivity in products was increased dramatically compared to other catalysts. It was confirmed that a plasma-photocatalytic hybrid system was better for toluene decomposition compared to photocatalytic and plasma only systems.

Active Network Management System with Automatic Generation of Network Management Program using Triggers (트리거를 이용한 네트워크관리프로그램 자동생성 기능을 가진 능동적인 네트워크 관리 시스템)

  • Shin, Moon-Sun;Lee, Myong-Jin
    • Journal of Internet Computing and Services
    • /
    • v.10 no.1
    • /
    • pp.19-31
    • /
    • 2009
  • Network management involves configuring and operating various network elements in a suitable manner. Generally, a network management system can perform basic functionalities such as configuration management, performance management, and fault management. Due to the open structure of the Internet, the volume of network traffic and the network equipment used have increased in size and complexity. Therefore, it is expensive and time consuming to develop a network management program for heterogeneous network equipment in an SNMP.based network. In order to facilitate the management of network environments and the control of heterogeneous devices in an efficient manner, we propose an Active Network Management System (ANMS) comprising an automatic generator that uses triggers to generate a network management program. The concept of triggers can be represented through event condition action rules performed in response to a change in the status of a network environment. The proposed ANMS comprises basic components for real time network management and also includes an automatic generator (AG). When the ANMS is monitoring network elements that are newly added or changed, a trigger rule is activated and these components are then able to collaborate and automatically generate a new network management program by using the information provided along with the SNMP libraries. Our method is useful for expanding the network structure and replacing network equipment. Through experiments, we have proved that our ANMS is useful when new network objects are added or changed in the network environment to expand the network structure. Further, we have verified that our ANMS system reduces the time and cost required to develop a network management program as compared to the manual method used in existing network management systems.

  • PDF

Miscibility and Specific Intermolecular Interaction Strength of PBl/Pl Blends Depending on Polyimide Structures (폴리이미드의 구조에 따른 방향족 PBI/PI 블렌드의 상용성 및 상호작용의 세기)

  • Ahn, Tae-Kwang
    • Applied Chemistry for Engineering
    • /
    • v.9 no.2
    • /
    • pp.185-192
    • /
    • 1998
  • Four kinds of polyamicacids(PAAs) were prepared by the condensation reaction of four diamines with different linkages, 3,3'-diaminodiphenyl sulfone(3,3'-$DDSO_2$), 4,4'-diaminodiphenyl sulfone(4,4'-$DDSO_2$), 4,4'-methylene dianiline(4,4'-MDA) and 4,4'-oxydianiline(4,4'-ODA), and dianhydride, 3,3', 4,4'-benzophenone tetracarboxylic dianhydride (BTDA) using the solvent, dimethylacetamide(DMAc). These four PAAs were blended with poly[2,2-(m-phenylene)-5,5'-bibenzimidazole](PBI) from the solution blending. Then called as Blend-I, II, III, and IV, respectively. Cast films or precipitated powders of the PBI/PAA blends were cured at a higher temperature than expected Tg to transform into PBI/PIs blends. Miscibility, specific intermolecular interaction for miscibility and their relative strength as a function of polyimide chemical structure with different four diamines in the PBI/PI systems were investigated. Four blends used in this study were all miscible, and the specific intermolecular interactions existing in these blends was thought to be the hydrogen bonding between the N-H of PBI and the C=O of PIs. The hydrogen bonding in the blends were shown to be stronger in the Blend-III and Blend-IV than Blend-I and II. It is speculated that the differences of hydrogen bonding strength of PBI/PI blends are dependent upon chemical structures of PIs, that is, PIs consisting of $SO_2$ group have a weaker hydrogen bonding strength than those of O or $CH_2$ group because the former has a larger spacer than the latter.

  • PDF