• 디지털산업정보학회논문지
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• 제16권2호
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• pp.53-59
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• 2020

Malicious file upload attacks mean that the attacker to upload or transfer files of dangerous types that can be automatically processed within the web server's environment. Uploaded file content can include exploits, malware and malicious scripts. An attacker can user malicious content to manipulate the application behavior. As a method of detecting a malicious file upload attack, it is generally used to find a file type by detecting a file extension or a signature of the file. However, this type of file type detection has the disadvantage that it can not detect files that are not encoded with a specific program, such as PHP files. Therefore, in this paper, research was conducted on how to detect and block any program by using essential commands or variable names used in the corresponding program when writing a specific program. The performance evaluation results show that it detected specific files effectively using the suggested method.

• 펄프종이기술
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• 제41권5호
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• pp.44-49
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• 2009

Old newspaper was deinked using commercial cellulolytic enzymes and a surfactant complex at low alkalinity. The properties of the deinked pulp(DIP) were evaluated and the suspended solids content, cationic demand, turbidity, and chemical oxygen demand(COD) of the process water were measured. The results can summarized as follows, 1. The brightness and yield of the DIP were improved using enzymatic surfactant complex deinking. 2. The amount of foaming during deinking with the enzyme surfactant complex was higher than that with synthetic surfactant deinking. However, it was not sufficient to cause process problem. 3. The pH and turbidity of the white water from deinking with the enzyme surfactant complex were similar to those of the white water from surfactant deinking. 4. The suspended solids content, cationic demand, and COD of the white water from deinking with the enzyme surfactant complex were improved compared to those of the white water from surfactant deinking.

• 펄프종이기술
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• 제32권2호
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• pp.16-25
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• 2000

The influence of four process parameters of soft nip calendering including calendering pressure, temperature, moisture content and nip residence time on bulk, smoothness and tensile strength of newsprints has been investigated. In addition, the effect of basis weights on calendering responses has been examined. Bulk of newsprints decreased and smoothness increased with the increase of the calendering pressure, temperature, moisture content of the sheets and nip residence time. Improvement in tensile strength was observed when low calendering pressure and high temperature of heat-ing roll were employed. Tensile strength of the newsprint, however, decreased abruptly when the calendering temperature and pressure increased above certain levels due to the rupture of sheet structure, which has been verified by SEM. SEM micrographs also showed that it would be possible to maintain the inner bulk while densifying the fibers on the outer surface of newsprint by adjusting the soft nip calendering variables properly.

• 펄프종이기술
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• 제48권2호
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• pp.99-105
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• 2016

The increase of wet web solid content after wet press and dry compressive strength were observed in lab study by judicious application of wood flour and starch for the old corrugated container (OCC). Pearl starch was better than cationic starch in strength development, but cationic starch was better for drainage. Application of vacuum on the mixed solution of wood flour and starch helped strength development further without loss of other properties. The effect of wood flour addition on wet web solid content improved as the wet pressing pressure increased. The use of wood flour and starch mixture improved wet web solid contents further.

• 펄프종이기술
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• 제42권3호
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• pp.37-42
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• 2010

The properties of paper are very susceptible to moisture content originated from relative humidity. This propensity of PVA impregnated paper was investigated in this study. Especially the hardening effect of borax treatment after PVA impregnation on the response of paper sample to the relative humidity was evaluated. When the moisture content was increased with the relative humidity, tensile stretch and tear resistance were increased while tensile strength and stiffness were decreased. A great increase in folding endurance of PVA impregnated paper sample was found at the higher relative humidity. The borax treatment could reduce the response of PVA impregated paper to the relative humidity.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제52권12호
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• pp.616-623
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• 2003

Conventional P/PI speed controller of today's servo drives should be manually tuned the controller switching set-point by trial-and-errors, which may translate the drive system down-time and loss of productivity. The adjustable drive performance is heavily dependent on the quality of the expert knowledge and becomes inadequate in applications where the operating conditions change in a wide range, i.e., tracking command, acceleration/deceleration time, and load disturbances. In this paper, the demands on simple controls/setup are discussed for industry servo drives. Analyzing the frequency content of motor torque command, P/PI control mode switching is automatically performed with some prior knowledge of the mechanical dynamics. The dynamic performance of the proposed scheme assures a desired tracking response curve with minimal oscillation and settling time over the whole operating conditions. For comprehensive comparison of traditional P/PI control scheme, extensive test is carried out on actual servo system.

• 펄프종이기술
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• 제34권2호
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• pp.22-31
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• 2002

In this paper, PVA(polyvinylalcohol), oxidized starch and SBR latex were used as binders for ink-jet printing papers, and their effects of the type and blending ratio of binders on ink-jet printing properties were compared. In case of coating color using PVA mainly used for a binder in ink-jet printing, spreading of printed letters decreased and excellent images were manifested resulting from strong hydrophilic of PVA. However, increasing solids content of coating color was somewhat limited because of the interaction of PVA and functional groups in silica as well as high molecular weight of PVA. When oxidized starch and SBR latex were mixed with PVA at desirable ratio to solve these problems, runnability in coating process was improved and good printing properties were shown. Gloss was improved when latex was used along with PVA as a binder because of the thermoplastic property of the latex. From this result, possibilities of high solids content and high gloss ink-jet printing papers were investigated.

• 한국펄프종이공학회:학술대회논문집
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• 한국펄프종이공학회 2000년도 춘계학술발표논문집
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• pp.103-110
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• 2000

This study was done in order to increase production speed using coater dryer in maximum capacity without print mottle. The aim of this study was to measure coating color immobilization content(CCIC) and to decrease CCIC through coating color optimization. The final goal of this study was the prevention of print mottle in maximum drying condition by CCIC control. As a result the measuring method of CCIC was set by brightness transition and the effective factors in pigments and binders were defined. With color optimization considered this factors, CCIC was decreased by 4%. Through this CCIC decrease and modification of coater utility, the print mottle was prevented even though using coater dryer in maximum.

• 디지털산업정보학회논문지
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• 제9권4호
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• pp.213-226
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• 2013

Recently, the social commerce on Facebook.com and Twitter.com, which is represented by SNS (Social Network Service), has been expanding in the form of a combination of SNS market. This study attempted to examine the cost-effect analysis between portal-based advertisement and SNS-based advertisement in order to establish an effective advertising strategy for e-learning content providers. The results showed that portal-based advertisement is more effective than SNS-based advertisement in terms of advertising effectiveness against cost. According to these empirical research results, this article discusses the practical implications for e-learning content providers in an attempt to enable them to take competitive advantage.

• 펄프종이기술
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• 제43권1호
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• pp.29-35
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• 2011

Since the role of lignin in the wood cell wall is to keep integrity and structure rigidity of lignocellulosic substrate, lignin of the cell wall has to be destroyed before enzymatic hydrolysis of wood polysaccharides. The aspen wood meals were delignified with ozone in acidic condition. The chemical characteristics of wood meal were investigated. The 60% of lignin and almost zero % of polysaccharides in aspen wood meal was degraded with 10min. ozone treatment. The phenolic hydroxyl groups of lignin in ozonated wood meal were increased with ozonation time. The sugar composition of ozonated wood meal showed that the hemicellulose was more susceptible to ozonation than cellulose. The yield of aldehyde was increased in some degree with 10min. ozone treatment and decreased with longer ozone treatment.