• Journal of the Korean Home Economics Association
• /
• v.35 no.2
• /
• pp.111-122
• /
• 1997

This thesis researched for the conservation of a suit of armor, one glove, one belt, and on knife case that General Jung, Gong-chung had been worn in the early 17 th centuries. The armor was Doojung-kab for the battle. It was made of two kinds of fabrics, one of them was silk satin's outer fabrics, the other was quilt4d cotton's lining. as the armor was made of silk and cotton, it was treated by dry solvents and dry soap. In the dry cleaning method, used solvents were n-hexane, cyclohexane, benzene, and n-decane. the volume ratio of dry soap was 120: 1. The reaction temperature was 30℃, and reaction time was 10 to 30 minutes per one turn. The glove, belt and knife case were made with leather. They were dipped on the polyethyleneglycol 150 saturated solution during 24hours at 50℃ and then dried naturally. They were washed by toluene to remove the untreated pp.E.G. on the surfaces. It was sterilized by two gases of methylenebromide and ethyleneoxied. For the conservation, it was packed thoroughly by ？ polyethylene film sheet without air.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.27 no.4
• /
• pp.608-613
• /
• 2003

In this paper, the effect of interconnected boundary between journal and thrust bearings on the performance of self-acting air-lubricated bearings is investigated. When journal and thrust bearings have common boundary, conventional boundary condition which assumes that the boundary pressure is equal to atmosphere is no more valid. Instead, new boundary condition by mass conservation at interconnected boundary is needed. To do this, a duct model satisfying mass conservation at interconnected boundary is developed. Using this model, pressure distribution at interconnected boundary is numerically analyzed with changing the volume of interconnecting part. As a result, it is shown that load capacity of thrust bearing can be greatly increased when journal and thrust have a common boundary.

• Nuclear Engineering and Technology
• /
• v.55 no.12
• /
• pp.4395-4407
• /
• 2023

Bubble columns are widely encountered in several industries, especially in the field of nuclear safety. The Eulerian-Eulerian and the Eulerian-Lagrangian methods are commonly used to investigate bubble columns. Eulerian approaches require additional tasks such as strict volume conservation at the interface and a predefined well-structured grid. In contrast, the Lagrangian approach can be easily implemented. Hence, we introduce a fully Lagrangian approach for the simulation of bubble columns using the discrete bubble model (DBM) and moving particle semi-implicit (MPS) methods. Additionally, we propose a rigorous method to estimate the volume fraction accurately, and verified it through experimental data and analytical results. The MPS method was compared with the experimental data of Dambreak. The DBM was verified by analyzing the terminal velocity of a single bubble for each bubble size. It agreed with the analytical results for each of the four drag correlations. Additionally, the improved method for calculating the volume fraction showed agreement with the Ergun equation for the pressure drop in a packed bed. The implemented MPS-DBM was used to simulate the bubble column, and the results were compared with the experimental results. We demonstrated that the MPS-DBM was in quantitative agreement with the experimental data.

• Journal of the Korean GEO-environmental Society
• /
• v.14 no.11
• /
• pp.5-12
• /
• 2013

The purpose of this study is to estimate the behavior and the mechanism of debris flow at the end of mountain side when a berm was set on the inclined plane. The numerical model was performed by using the Finite Difference Method(FDM) based on the equation for the mass conservation and momentum conservation. In order to measure the behavior of the debris flow, the debris flow of a straight channel slope and the debris flow of channel slope with 3 types of berms were compared. First, the flow discharge and the sediment volume concentration at the downstream of the channel slope, depending on the various berm width and the different inflow discharges at the upstream of the channel were analyzed. The longer the berm width, the flow discharge at the downstream of the channel was decreased and the high flow fluctuation was reduced by a berm. And it means that a berm can effect for the delay of the debris flow. Through Root Mean Square ratio(RMS) comparison, the flow discharge of the channel slope with a berm was lower than that of a straight channel slope. The longer the berm width, for the sediment volume concentration, an inflection point did not show but mild curve. Because the low sediment concentration with water mixture by a berm continuously flow at the downstream end, it will be effect for reducing the disaster caused by debris flow. The results of this study will provide useful information in predicting and preventing disaster caused by the debris flow.

• Journal of Korean Society on Water Environment
• /
• v.32 no.6
• /
• pp.562-569
• /
• 2016

Recently, Low Impact Development (LID) is being used in Korea to control urban runoff and nonpoint source pollution. In this study, we evaluated the reduction of surface runoff from a study area, as the effect of connecting three bioretention as LID-BMP. Surface runoff and storage volume of bioretention is estimated by the Curve Number (CN) method. In this study, the storage volume of bioretention is divided by the volume of surface runoff and precipitation which directly enters the bioretention. The ratio of captured surface runoff volume to storage volume is highly influenced by the ratio of drainage area to surface area of bioretention. The high bioretention surface area-to-drainage area ratio captures more surface runoff. The ratio of 1.2 captures 51~54% of the total surface runoff, ranging from 5-30cm of bioretention depth; a ratio of 6.2 captures 81~85%. Three connected bioretentions could therefore captures much more runoff volume, ranging from $35.8{\sim}167.3m^3$, as compared to three disconnected bioretentions at their maximum amount of precipitation with non-effluent from the connecting three bioretentions. Hence, connecting LID-BMPs could improve the removal efficiencies of surface runoff volume and nonpoint source pollution.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.29 no.5B
• /
• pp.429-439
• /
• 2009

When Catastrophic extreme flood occurs due to dam break, the response time for flood warning is much shorter than for natural floods. Numerical models can be powerful tools to predict behaviors in flood wave propagation and to provide the information about the flooded area, wave front arrival time and water depth and so on. But flood wave propagation due to dam break can be a process of difficult mathematical characterization since the flood wave includes discontinuous flow and dry bed propagation. Nevertheless, a lot of numerical models using finite volume method have been recently developed to simulate flood inundation due to dam break. As Finite volume methods are based on the integral form of the conservation equations, finite volume model can easily capture discontinuous flows and shock wave. In this study the numerical model using Riemann approximate solvers and finite volume method applied to the conservative form for two-dimensional shallow water equation was developed. The MUSCL scheme with surface gradient method for reconstruction of conservation variables in continuity and momentum equations is used in the predictor-corrector procedure and the scheme is second order accurate both in space and time. The developed finite volume model is applied to 2D partial dam break flows and dam break flows with triangular bump and validated by comparing numerical solution with laboratory measurements data and other researcher's data.

• Journal of Korean Society of Forest Science
• /
• v.112 no.2
• /
• pp.209-216
• /
• 2023

This study aimed to use national forest inventory data to develop a forest productivity index and yield prediction model of a Tilia amurensis stand. The site index displaying the forest productivity of the Tilia amurensis stand was developed as a Schumacher model, and the site index classification curve was generated from the model results; its distribution growth in Korea ranged from 8-16. The growth model using age as an independent variable for breast height and height diameter estimation was derived from the Chapman-Richards and Weibull model. The Fitness Indices of the estimation models were 0.32 and 0.11, respectively, which were generally low values, but the estimation-equation residuals were evenly distributed around 0, so we judged that there would be no issue in applying the equation. The stand basal area and site index of the Tilia amurensis stand had the greatest effect on the stand-volume change. These two factors were used to derive the Tilia amurensis stand yield model, and the model's determination coefficient was approximately 94%. After verifying the residual normality of the equation and autocorrelation of the growth factors in the yield model, no particular problems were observed. Finally, the growth and yield models of the Tilia amurensis stand were used to produce the makeshift stand yield table. According to this table, when the Tilia amurensis stand is 70 years old, the estimated stand-volume per hectare would be approximately 208 m³ . It is expected that these study results will be helpful for decision-making of Tilia amurensis stands management, which have high value as a forest resource for honey and timber.

• Proceedings of the Korea Water Resources Association Conference
• /
• 1998.05b
• /
• pp.3-3
• /
• 1998

In this pressentation it is argued that the heterogeneity of a hydrologic attribute which may seem to be nonstationary at one scale, may become stationary at a larger scale. The fundamental reason for transformation from nonstationarity to stationarity whith the increase in scale is the phenomenon of coarse-graining of the hydrologic processes with increasing scale. Due to the phenomenon of aliasing, a particular scale hydrologic process heterogeneity which is observed as a nonstationary process at that scale, may be observed as a stationary process at a higher(larger) scale whose size is bigger than the stationary extent of the lower scale heterogeneity. As one goes through a hierarchical sequence of larger and larger scales for observations, one would eliminate nonstationarities which emerge at some lower scales at the expense of losing information on the high frequency fluctuations of the lower scale heterogeneities which will no longer be observed at the larger sampling scales. We call this phenimenon as the "coarse-graining in hydrologic observations". In this presentation, it is also argued that by the coarse-graining of hydrologic processes due to the averaging and aliasing operations at increasing scales, the conservation laws corresponging to these scales may still be quite parsimonious, and need not be more complicated as the scales get larger. It is shown that shen a higher(larger) scale process is formed by averaging a lower(smaller) scale process in time or space, the high frequency components of the lower scale process will be eliminated by the averaging operation. Thereby, the resuliiting average hydrologic dynamics, free from the effects of the high frequency components of the lower scale process, can still be quite simple in form. This is demonstrated by means of some recent upscaling work on the solute teansport conservation equation for hetergeneous aquifers. By means of this solute transport example, it is also shown that for the ensemble average form of a hydrologic conservation equation to be equivalent to its volume-average form at any scale, the parameter functions of that conservation equation at the immediately lower scale must be ergodic.

• Conservation Science in Museum
• /
• v.22
• /
• pp.27-40
• /
• 2019

Minutes of cabinet meetings (hereafter referred to as "minutes") offer records on important activities of the government of the Republic of Korea. The National Archives of Korea has implemented a series of preservation for these minutes such as condition survey, deacidification, microfilming, digitization, making boxes, etc. Conservation treatment plans were further established in 2018 to pursue more preservation of over 2,000 volumes of minutes based on the result of the condition survey of the minutes. Among ninety-seven volumes that require conservation treatments, six volumes have been treated so far. A major concern of conservation treatment of minutes was found that a single volume of minutes contains 800 pages, leading to heavier and bulkier than most of other bound volumes. This paper presents the measures taken to solve the problems resulting from this bulky structure of the bound minutes. It is expected that the study will offer an opportunity to consider effective conservation methods for records on paper of which the physical shapes are yet to be determined.

• Korean Journal of Heritage: History & Science
• /
• v.47 no.4
• /
• pp.106-119
• /
• 2014

The $76^{th}$ National Treasure is consisted of seven volumes of Nanjung Ilgi (War Diary of Admiral Yi Sun-sin; each titled by the author based on the zodiac name of the year covered, i.e. Imjin Ilgi, Gyesa Ilgi, Gabo Ilgi, Byeongsin Ilgi, Jeongyu Ilgi, Sok Jeongyu Ilgi, Musul Ilgi), Seogancheob (Letters of Admiral Yi) and Imjin Jangcho (Drafts of Imjin War Reports of Admiral Yi). These are currently in the custody of Hyeonchungsa shrine, the state-managed memorial shrine of Admiral Yi, and has been added to UNESCO's Memory of the World Register in June 2013 in the appreciation of its historical and academic importance as a commander's hand-written battlefield accounts during Japanese invasions of Korea. Imjin Jangcho, among these nine volumes, is a record of battles, including observations on the enemy fleets, suggestions on naval matters, battle expenditure, and methods of battle preparation, transcribed by someone else according to Admiral Yi's instructions. It is Admiral Yi's honest detailobservations on the war situation during Japanese invasions of Korea from 1592 as a Naval Commander of Left Jeolla Province, till 1594 (Year 27 of King Seonjo's reign) as a Commander-in-Chief of the Naval Forces of the South. It is a draft of the war report to be submitted to the King in a single volume as a folio (each sheet folded once to produce one leaf) bound in a side-stitched binding with five holes and inner binding of twisted paper. This study explores the condition and the treatment performed on Imjin Jangcho which could have an implication for the conservation of cultural assets on paper of late Joseon Dynasty.