• Journal of Conservation Science
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• v.29 no.1
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• pp.47-54
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• 2013

The following study tests for the effects of mordants on the production of restoration papers during the conservation process of damaged paper artifacts. For this, four different types of synthetic mordants that are being marketed currently ($K_2CO_3$, $AlK(SO_4)_2{\cdot}12H_2O$, $Cu_2SO_4{\cdot}5H_2O$, $FeSO_4$) were selected to produce samples for measuring variable properties through artificial degradation. The research conducts tests for changes in color, tensile index, and pH level (degree of acidity). The results for changes in color have shown that the value of ${\Delta}E^*ab$ of $K_2CO_3$ mordant sample was the highest, and the tests for tensile index have shown that the strength of dyeing sample was decreased in accordance with the aging time, but Changes according to the mordant was not evident. Finally, the findings for pH level have shown that samples with $Cu_2SO_4{\cdot}5H_2O$ and $FeSO_4$ have pH levels drop below 6. As a result, the research have concluded that mordants used for dyeing restoration paper were identified to have an affect in the dyeing and aging characteristics of the paper.

• Applied Biological Chemistry
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• v.38 no.2
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• pp.135-140
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• 1995

Changes in pH of the soaking solution and physical properties of the soybean curd during immersing in solution of different concentrations at different temperatures were determined. Compared with $0{\sim}3%$ NaCl soaking solution, 5% NaCl soaking solution distinctively reduced the pH drop, increasing rate of turbidity and microorganism growth during storage. This indicated the concentration of soaking solution influences the shelf life of curd. As the storage temperature was lowered to $5^{\circ}C$, their changing rates were also reduced. Physical properties such as initial stress $({\sigma}_0)$, elastic constant (E), viscous constant $({\eta})$ and failure test were influenced by storage temperature, but not a function of concentration of salt solution. The result of the sensory test indicated the hardness and salty taste of curd were statistically significant among samples and $1{\sim}5%$ NaCl solutions did not show any significant difference in the salty taste.

• Korean Journal of Environmental Agriculture
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• v.5 no.1
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• pp.61-66
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• 1986

A small pot experiment, filled with one hundred fifty gram of Cd amended soil, was conducted in order to learn the effect of combined application of lime and organic matter and of calcium silicate on Chinese cabbage(Brassica pekinensis, Var. Seoul, Heungnong, Miho 70 days). Results obtained are as follows: 1. The application of lime without organic matter depressed the growth of cabbage at the first and second harvests, but, at the later part of third harvest the growth was facilitated so as to harvest very good yield. 2. The combined application of lime and organic matter gave not only a good growth of cabbage from the first crop, but also lowered the cadmium content of dry cabbage bellow that of cabbage harvested from the plot applied with slaked lime alone. Those effect of combined application of both materials were lasted untill the third harvest. 3. Although gave little effect on soil pH, calcium silicate raised a normal good cabbage, and depressed the cadmium content of dry cabbage, by 0.21 me per 100g, which is higher than that of slaked lime plot cabbage, but within the range of no harm to cabbage growth. 4. The control and organic matter plots resulted in a remarkable soil pH drop and high cadmium content in dry cabbage, which lead the crop to a death from the second crop. 5. A negative correlation was observed between the contents of cadmium and calcium in dry cabbage crop, but positive correlations between those of cadmium and magnesium or cadmium and potassium. These relations were grown up as the harvesting were proceeding.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.5
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• pp.55-63
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• 2018

Recently, the use of duplex stainless steel which with a two-phase microstructure (equal mixture of ferrite and austenite) has been increased in a variety of industrial fields due to higher strength leading to weight saving, greater corrosion resistance(particularly, stress corrosion cracking) and lower price. However, currently, stainless steels are not included in the structural materials of Korean Building Code and corresponding design standards are not specified. In this paper, experimental studies have been performed to investigate the structural behaviors of duplex stainless steel (STS329FLD) bolted connection with two bolts for providing the design data. Main variables are shear connection type (single shear and double shear) and end distance parallel to the direction of applied force. Fracture modes at the final step of test were classified into typical block shear fracture, tensile fracture and curling. Curling occurrence in single shear connection led to ultimate strength drop by up to 20%. Test strengths were compared with those by current design specifications such as AISC/AISI/KBC, EC3 and AIJ and proposed equations by existing studies. For specimens with no curling, Clement & Teh's equation considering the active shear plane provided a higher strength estimation accurancy and for specimens with curling, Kim & Lim's equation considering strength reduction by curling was also overly unconservative to predict the ultimate strength of curled connections.

• Journal of the Optical Society of Korea
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• v.15 no.2
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• pp.174-181
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• 2011

An airborne sensor is developed for remote sensing on an aerial vehicle (UV). The sensor is an optical payload for an eletro-optical/infrared (EO/IR) dual band camera that combines visible and IR imaging capabilities in a compact and lightweight package. It adopts a Ritchey-Chr$\'{e}$tien telescope for the common front end optics with several relay optics that divide and deliver EO and IR bands to a charge-coupled-device (CCD) and an IR detector, respectively. The EO/IR camera for dual bands is mounted on a two-axis gimbal that provides stabilized imaging and precision pointing in both the along and cross-track directions. We first investigate the mechanical deformations, displacements and stress of the EO/IR camera through finite element analysis (FEA) for five cases: three gravitational effects and two thermal conditions. For investigating gravitational effects, one gravitational acceleration (1 g) is given along each of the +x, +y and +z directions. The two thermal conditions are the overall temperature change to $30^{\circ}C$ from $20^{\circ}C$ and the temperature gradient across the primary mirror pupil from $-5^{\circ}C$ to $+5^{\circ}C$. Optical performance, represented by the modulation transfer function (MTF), is then predicted by integrating the FEA results into optics design/analysis software. This analysis shows the IR channel can sustain imaging performance as good as designed, i.e., MTF 38% at 13 line-pairs-per-mm (lpm), with refocus capability. Similarly, the EO channel can keep the designed performance (MTF 73% at 27.3 lpm) except in the case of the overall temperature change, in which the EO channel experiences slight performance degradation (MTF 16% drop) for $20^{\circ}C$ overall temperate change.

• Journal of Korean Orthopaedic Sports Medicine
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• v.3 no.1
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• pp.66-72
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• 2004

Purpose: To evaluate the compensatory mechanism in vivo and develop the treatment guide by performing the comprehensive functional tests of the posterior cruciate ligament (PCL) deficient subjects. Material and Methods: 10 PCL deficient subjects and 10 healthy control group were evaluated. Performed functional tests were range of motion, posterior drawer test, Telos, 30$^{\circ}$ flexion wt-bearing view, KT-1000 arthrometer, gait analysis, EMG test and isokinetic tests. Results: Physical, KT-1000, Telos posterior tests showed significant differences, but 300 full weight bearing lateral view, muscle strength test revealed no difference between two groups. Less knee flexion at initial contact and reduced maximum valgus moment were observed in PCL deficient group. In vertical drop landing, PCL group had increased plantar flexion angle at initial contact. Conclusion: Compensatory mechanisms such as reduced unstable components and absorbing the maximal load of the joint were occurred after PCL insufficiency, which result in good clinical and functional outcomes. Further investigations would be needed to understand the functional adaptations of PCL deficient subjects.

• Particle and aerosol research
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• v.13 no.2
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• pp.79-85
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• 2017

This study identified the loss of minimum fluidization velocity and pressure in accordance with the superficial velocity of $NiO/MoO_3/MoS_2$, a rare metallic oxide and high value-added material in the lab-scale fluidized bed reactor (L=0.25 m, D=0.05 m). The average pressure loss in L/D 1, 2, and 3 of $NiO/MoO_3/MoS_2$ within the scope of superficial gas velocity between 0.07 and 0.45 m/s based on the L/D 1, 2, and 3 of the specimen was shown to be 290~1952 Pa at decreasing flux and 253~1925 Pa at increasing flux. The comparison between the theoretical value proposed by Wen and the test data showed a difference between 0.021~0.36 magnification. Based on these results, this study was able to determine the operation conditions where rare metallic oxides could be applied in real phenomena.

• Journal of the Korean GEO-environmental Society
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• v.19 no.11
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• pp.5-14
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• 2018

Worldwide, soil compaction work is one of the most important activities that are carried out on civil engineering works sites. Compaction work, particularly in the area of road construction, is considered to be important, as poor compaction work is closely related with poor construction even after a construction is complete. Currently, the plate bearing test or the sand cone method relative to the unit weight of soil test are commonly used to measure the degree of compaction, but as these require a great deal of time, equipment and manpower, it is difficult to secure economic efficiency. The method that is used to measure the degree of compaction according to the penetration depth achieved by free fall objects through gravity is the Free-Fall Penetration Test (FFPT), which uses a so-called "portable compaction measuring meter (PCMM)." In this study, the degree of compaction was measured and a penetration depth graph was developed after the field test using the portable compaction measuring meter. The coefficient of determination was 0.963 at a drop height of 10 cm, showing the highest level of accuracy. Both horizontal axis and longitudinal axis were developed in a decimal form of graph, and the range of allowable error was ${\pm}1.28mm$ based on the penetration depth. The portable compaction measuring meter makes it possible to measure the degree of compaction simply, quickly and accurately in the field, which will ensure economic efficiency and facilitate the process management.

• Korean Journal of Agricultural and Forest Meteorology
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• v.6 no.4
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• pp.211-217
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• 2004

The instrument used in this study consists of a lkg capacity loadcell and a Imm tipping bucket rain gauge. There are two signals: one is the weight of the water in the tipping bucket and the other is the pulse from the reversing mechanism of the tipping bucket. The loadcell measures the weight of water with a 0.0lmm resolution up to 1mm rainfall and the bucket reverses beyond 1mm. From this point, a pulse signal generates and the loadcell starts measuring the weight again. A field test was carried out with the range of rainfall intensity from 42mm/h to 250mm/h. The result shows an error range from -2.2% to + 2.6% in 12 measurement cases with a rainfall of l00mm or more. This result satisfies the WMO recommendation for rainfall intensity instrumentation which allows a 5% range. In a field experiment during 17 to 19 August, 2004, more than 100mm/h rainfall intensity was observed by this instrument, confirming that our instrument has a sufficient capacity of rainfall intensity measurement under extreme conditions like Jangma (Bai-u season). Compared with existing commercial models which employ a water drop measurement method, our method can give a practical solution for diagnostic check of remote rain gauges using two independent signals.

• Korea journal of population studies
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• v.33 no.2
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• pp.85-111
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• 2010

South Korea has experienced a rapid fertility decline and notable mortality improvement. As the drop in TFR was quicker and greater in terms of tempo and magnitude, it cast a new challenge of population projection - how to improve the forecasting accuracy in the country with a super-low fertility pattern. This study begin with the current status of the national population projection as implemented by Statistics Korea by comparing the 2009 interim projection with the 2006 official national population projection. Secondly, this study compare the population projection system including projection agencies, projection horizons, projection intervals, the number of projection scenarios, and the number of assumptions on fertility, mortality and international migration among super-low fertility countries. Thirdly we illustrate a stochastic population projection for Korea by transforming the population rates into one parameter series. Finally we describe the future challenges of the national population projection, and propose the projection scenarios for the 2011 official population projection. To enhance the accuracy, we suggest that Statistics Korea should update population projections more frequently or distinguish them into short-term and long-term projections. Adding more than four projection scenarios including additional types of "low-variant"fertility could show a variety of future changes. We also expect Statistics Korea topay more attention to the determination of a base population that should include both national and non-national populations. Finally we hope that Statistics Korea will find a wise way to incorporate the ideas underlying the system of stochastic population projection as part of the official national population projection.