• Korean Journal of Heritage: History & Science
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• v.42 no.4
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• pp.4-19
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• 2009

Though admitting that, in light of the recent archaeological trend, the excavation on relics of Sam-gama (a sort of kiln steaming the hemp) is increasingly reported, little efforts by far have been made not only to restore its traditional structure design but also to research hardly the change of hemp-steaming technologies in ages. In this regard, this paper shows the exploration of structural method and design as well as operability with regard to Sam-gut, traditional hemp-processing equipment that was recently reconstructed in Jungsun, Kangwon Province. Samgut, generally positioned at the waterside area, is an traditional device for steaming hemp to get bast fibers from the raw material of hemp, principally consisting of HWA-JIP(fire-place) to obtain steams by feeding fire ad Mong-got(boiling chamber) to make the hemp steamed after stacking. More specifically, thick round-logs were piled at the bottom of Hwajip prior to stacking stones around its circumferential area. When the timber positioned below gets burned with high temperature to heat stones existing in the upper side, waters then poured onto it after laying a bundle of grass and soil up to the boiled stones. If so, there generates hot vapor, which is conveyed to Monggot to steam the hemp. Functionally, it is of outstanding importance that Samgut is capable of producing high-temperature water vapors instantaneously under the intensive manpower, thus being constructed achievable for those purposes. The Samgut made by digging the ground is an instant facility that is closed after use. The remains, which were used to generate higher thermal power for steaming hemp, make it hard to excavate the historic traits because there left little vestiges in the soil, which means keen attention must be paid to find out the trace of Smgama relics. Future research stall be focused on collection of broader data regarding Samgut including technological review in extracting bas fibers from the hemp.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.8
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• pp.1647-1652
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• 2011

This paper presents the shielding effectiveness for the IEC 61000-2-9 standard when HEMP source penetrates through an aperture in a planar conducting plane of infinite extent. An integral equation is derived and solved by applying Galerkin's method of moments for calculating the electric shielding effectiveness. The electric shielding effectiveness is examined based on changing the aperture length and width. It is shown that the electric shielding effectiveness is suddenly decreases as the aperture width of 0.4 ~ 0.45${\lambda}$. It is also found that the penetrated electric field for the IEC 61000-2-9 incident field is different from the Bell Laboratory incident field, but the frequency characteristic of the electric shielding effectiveness becomes the same shape.

• Fibers and Polymers
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• v.3 no.4
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• pp.129-133
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• 2002

It is well known residual gum exists in degummed or rotted hemp fibers. Gum removal results in improvement in fiber fineness and the properties of the resultant hemp yams. However, it is not known what correlation if any exists between the residual gum content in retted hemp fibers and the fiber fineness, described in terms of fiber width in this paper. This study examined the mean width and coefficient of variation (CV) of fiber width of seventeen chemically rotted hemp samples with reference to residual gum content. The mean and CV of fiber width were obtained from an Optical fiber diameter analyser (OFDA 100). The linear regression analysis results show that the mean fiber width is directly proportional to the residual gum content. A slightly weaker linear correlation also exists between the coefficient of variation of fiber width and the residual gum content. The strong linear co-relation between the mean of fiber width and the residual gum content is a significant outcome, since testing for fiber width using the OFDA is a much simpler and quicker process than testing the residual gum content. Scanning Electron Microscopy (SEM) reinforces the OFDA findings. SEM micrographs show a flat ribbon like fiber cross-section hence the term \"fiber width\" is used instead of fiber diameter. Spectral differences in the untreated dry decorticated skin samples and chemically treated and subsequently carded samples indicate delignification. The peaks at $1370cm^{-1}$, $1325cm^{-1}$, $1733cm^{-1}$, and $1600cm^{-1}$ attributed to lignin in the untreated samples are missing from the spectra of the treated samples. The spectra of the treated samples are more amine-dominated with some of the OH character lost.cter lost.

• Convergence Security Journal
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• v.19 no.3
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• pp.43-50
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• 2019

In a hyper-connected society, electric power infrastructures and information and communication infrastructures are the core of critical national infrastructures. However, electric power infrastructure is very deadly to high-frequency nuclear electromagnetic pulse (HEMP) threats recently issued by North Korea, so the resilience through rapid recovery after attack is directly related to the survivability of our country. Therefore, electric power infrastructure should take precedence over any other key infrastructure, with preemptive protection measures and fast recovery plans. In this paper, the characteristics of the HEMP threats was examined, and the risks and effective major protection measures of the electric power infrastructures are discussed. In the future, it is expected that it will be able to help establish the direction of enactment and revision of legal schems related to the 'high power EMP infringement prevention' for Korea's electric power infrastructures.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.23 no.3
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• pp.392-401
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• 2012

This paper gives a electromagnetic coupling mechanism of the high altitude electromagnetic pulse (HEMP) into large- scale underground multilayer structures using analytic and numerical methods. The modeling methods are firstly addressed to the HEMP source which can be generated by intentional nuclear explosion. The instantaneous and intense electromagnetic pulse of the HEMP source is concerned from DC to 100 MHz band, because the power spectrum of the HEMP is rapidly decreased under -30 dB over the 100 MHz band. Through this range, a penetrated electric field distribution is computed within the large-scale underground multilayer structures. As a result, the penetrated electric field intensities at 0.1 and 1 MHz are about 10 and 5 kV/m, respectively. Therefore, additional shielding techniques are introduced to protect buried structures within the large-scale underground structures such as high-lossy material and filtering structures (wire screen).

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.6
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• pp.644-653
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• 2013

In this paper, a formulation for obliquely incident electromagnetic wave has been presented for an analysis of highpower electromagnetic pulse penetration into multilayered dispersive media. Based on generalized models of measured dielectric constants and propagation channels reflecting the Earth's general features, the propagation phenomenon of the obliquely incident early-time(E1) high altitude electromagnetic pulse(HEMP) is analyzed. In addition, the polarization and critical angle are also considered. It is found that the total reflection occurs at an incident angle of about 38 degrees at the soil-rock interface, and that the parallel-polarized E1 HEMP penetrates better than the perpendicular-polarized one. The peak level of the penetrating electric field is found to be 5.6 kV/m at normal incidence, regardless of the type of polarization, and E1 HEMP is greatly reduced near the critical angle. Moreover, the penetrating E1 HEMP is analyzed as a variation of moisture content and depth of materials, resulting E1 HEMP could be useful in determining the levels of shielding required for buried facilities.

• Journal of Conservation Science
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• v.5 no.2 s.6
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• pp.57-64
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• 1996

Korean Paintings have been drawn on in the main two types of support material - paper and silk. In these things, silk designates picture silk, that of a specially weaved textile for painting since CHO-SUN dynasty, different such as hemp, ramie have been started to use for support material In addition to picture silk. However the structure of hemp and ramie are so close and progue, They are not proper to express the technique of pigments on the back of the paintings. On the other hand, picture silk is efficacious in pigments on the back of the painting with its interval between the strands and translucent textile. As the result, paintings on the silk has many - sided techniques as compared with painting on the papers therfore various devices in conservation have to be considered to deal with the techniques. In this report the focus is on classifying the method of removing the Lining paper according to the several types of expression technique of paintings on the silk.

• 보존과학연구
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• s.17
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• pp.65-99
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• 1996

We exanmined the each effect of $NO_2$ and $SO_2$gas, the maincomponets of air pollutants, on the deterioration of 6 organic materials with Gasexposure cabinet. The organic materials were used 2 kind of papers(Korean paper, Oldbook paper) and 4 kind of textiles (Cotton, Silk, Hemp, ramie) in gas exposure experiments. In order to know how to change of physical conditions, the materials were exposed to 2000, 1000 ppm. h of $SO_2$dose, to 100 ppm. h of $NO_2$ dose at 65% RH. The color difference, tensile strength, elongation coeffient, mass reduction and fabric status of each materials were discussed the following below.1. The color difference of cotton and hemp was larger than that of silk and ramie in the presence of $SO_2$ gas. and the color difference of korean paper was less than that of the textile materials in the presence of $SO_2$ gas.2. The tensile strength of cotton fell suddenly at 100ppm.h of $SO_2$ dose and even became 56% of the unexposed cotton.3. The weight of 6 materials began to decrease in the presence of $SO_2$ gas.4. The tensile strength and elongation of the materials tended to decrease at 12.5ppm.h of $NO_2$ especially silk was the strongest tendency to decrease.5. Cotton, hemp and ramie were influenced by $SO_2$ gas more than by $NO_2$, but silk were influenced by $NO_2$ more thang by $SO_2$ at 10ppm.h of each noxious gas.

• Journal of the Korean Home Economics Association
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• v.23 no.1
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• pp.11-17
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• 1985

This paper aims to examine the variety of the absorption of cotton, T/C and hemp fabrics seperately seperaterly sized by rice, wheat, potato, corn flour and pp.V.A.. Experimental variables occurring in the concentration of sizing agents, the water content of unsized fabrics and an iron temperature show the following results, 1. When fabrics sized, the rate of absorption increases according to the order of rice, corn, pp.V.A., potato, wheat flour for cotton fabrics, of rice, corn, pp.V.A., wheat, potato flour for hemp fabrics and of the rice, pp.V.A., potato, corn, wheat flour for T/C fabrics : rice flour shows an absorption rate highest among all the others mentioned above. 2. To a certain extent, the stronger the concentration of sizing agents, the higher the rate of absorption. 3. The higher fabrics density, the higher absorption rate. 4. The structure and hydrophilic property of the sized fabrics affect the rate of absorption. 5. The fabrics with water content of 20% before sizing it shows the rate of absorption highest. 6. An iron temperature after sizing fabrics shows the rate of absorption highest at the properest at the properest one : $180^{\circ}C$ for cotton, $150^{\circ}C$ for T/C and $200^{\circ}C$ for hemp fabrics.

• Journal of the Korean Home Economics Association
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• v.25 no.2
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• pp.31-38
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• 1987

This paper aims to examine the velocity of water absorption of cotton, hemp, and T/C fabrics sized by rice, wheat, potato, corn flour and pp.V.A.. Experimental variables such as the concentration of sizing agents, the moisture regain of unsized fabrics and the ironing temperature showed the following results. 1. When the fabrics were sized, the velocity of water absorption increased according to the order of corn, rice, potato, wheat flour and pp.V.A. for cotton fabrics, of corn, potato, rice, wheat flour and pp.V.A. for hemp fabrics, and of corn, wheat, rice, potato flour and pp.V.A. for T/C fabrics; corn flour showed the highest velocity of water absorption and pp.V.A. did the lowest among all the others mentioned above. 2. The higher fabric density, the higher velocity of water absorption. The finer the count of fabric yarn, the higher velocity of water absorption. 3. The material of sized fabrics most affected the velocity of water absorption than other factors of those. 4. To a certain extent, the higher the concentration of sizing agent, the higher the velocity of water absorption. 5. The fabrics with moisture regain of 20% before sizing showed the highest velocity of water absorption. 6. The ironing temperature after sizing fabrics mentioned below showed the highest velocity of water absorption; 180$^{\circ}C$ for cotton, 200$^{\circ}C$ for hemp, and 160$^{\circ}C$ for T/C fabrics.