• Magazine of the Korean Society of Agricultural Engineers
• /
• v.43 no.5
• /
• pp.63-69
• /
• 2001

The main purpose of this study is to seek desalinization effect of subsurface drainage system with rice hull packing in Dae-Ho Reclaimed Land. After 4 years installed sub-surface drainage system, distribution of drained water electric conductivity (ECw) was 4.43~12.78 ds/m. The soil profile showed partial development of the soil structure and compaction of subsoils with increased bulk density. The bulk density of the subsoil was 1.42~1.66 g/cm$^3$, which might limit root growth. The soil color changed near the drainage pipe line. Distribution of soil extract solution ECe and SAR as subsurface drainage pipe position and drainage canal distance showed desalinization effect of subsurface drainage system with rice hull packing as widening effective zone of subsurface drainage pipe.

• Journal of the Korea Institute of Building Construction
• /
• v.2 no.1
• /
• pp.163-169
• /
• 2002

In this study, there are kind of property experiments like fluidity, compressive strength, bleeding measurement, concrete sink for CFT use high fluidity concrete. The property difference between before transmit and after transmit concrete in the mock up test with ready mixed concrete equipment is examined. The variable factors in mock up are diaphragm existence and nonexistence, diaphragm placing hole sizes. To investing the concrete Property under diaphragm, concrete packing ability, hydration heat, core specimen strength tests are performed.

• Journal of the Korean Ceramic Society
• /
• v.31 no.9
• /
• pp.1044-1052
• /
• 1994

Tape casting technique was successfully applied to produce porous ceramics and multi-layered ceramics containing porous layers, where spherical hollow polymer particles were introduced as pore precursors. In the presence of extreme differences in density and size between Al2O3 and pore precursor particles, hindered settling was effective in preventing segregation of component particles and packing behavior of mixed powders was improved through bimodal packing. There were two transitions in packing behavior of mixed powders. The first transition took place at 40~50 vol% pore precursor addition, where majority of pores changed from close to open pore state. The other transition occured at 60~70 vol% pore precursor addition, where pore precursor particles formed a continuous network structure.

• Journal of Korean Society of Industrial and Systems Engineering
• /
• v.37 no.1
• /
• pp.157-164
• /
• 2014

The usage of corrugated cardboard for packing material is increasing in these days because it is light and easy to manufacture packing boxes. However, the structure analysis of packing boxes, made of cardboard, is not well carried. The reason can be deduced that its mechanical properties for structure analysis are not well known. The cardboards are made different shapes with various types of raw materials that are paper-based compound. In addition, the cardboards are considered to be orthotropic material. This research finds mechanical properties of triple layered cardboard which is composed of outer liner and inner liner. The moduli of elasticity and of shear for liners are found from tension test and T-Peel test. The mechanical properties of the cardboard are calculated using the super position method and equivalent evaluation method.

• Journal of Powder Materials
• /
• v.19 no.1
• /
• pp.1-5
• /
• 2012

In order to improve the remanence of (Nd, Dy)-Fe-B sintered magnets, we investigated the influence of compaction conditions such as packing density, applied field and green density on the magnetic properties. While the remanence decreased with increasing the packing density and green density, it increased with the increase of the applied field. In addition, XRD analysis revealed that the remanence was enhanced as the degree of powder alignment was improved. The green density was more influential on the remanence than the packing density and applied field.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.2 no.6
• /
• pp.110-116
• /
• 1994

In this research, the tensile strength of molded parts and pressure distribution were analyzed to study the cavity filling stage and packing stage in injection molding. The measurement of cavity pressure was obtained by a data acquisition system with the installation of transducers in the cavity. Molded parts were tested by a universal testing machine to obtain the tensile strength. For the experimental work, the tensile strength of molded parts increased with longer packing time and exact freezing time of the gate was obtained by a cavity pressure curve. In addition, the effect of packing did not occur and tensile strength was almost constant after early 1.5 sec of the freezing time of gate. Density tended to be higher about 0.2% due to a larger degree of mold temperature and melt temperature. Also, changing pressure in the cavity was effectively sensed. Thereafter, the possibility of the development of pattern recognition expert system was confirmed on the basis of the experimental results.

• Bulletin of the Korean Chemical Society
• /
• v.14 no.1
• /
• pp.34-34
• /
• 1993

The gelation phenomena of N-methylolated PAAm (M-PAAm) in aqueous media was studied. The critical gelation concentration (CGC) was very close to the calculated $C^*$ of the scaling theory. But the CGC of lower MW M-PAAm deviated from $C^*$ due to contamination of small molecules. We propose that the CGC is the close packing configuration of polymer molecules in solution. The experimental results of the gelation of M-PAAm/PAAm mixture proved that the close packing configuration is essential to make a gel. We calculated the minimum quantity of M-PAAm to make M-PAAm/PAAm mixture a gel by using the close packing configuration. We used a lattice model.

• Journal of the Korea Safety Management & Science
• /
• v.14 no.4
• /
• pp.193-203
• /
• 2012

In the limitless competition era of the 21st century, cost reduction is being highlighted as one of survival strategies of businesses. The first item for cost reduction of businesses is logistical costs. The most keenly required thing for this is to remove unnecessary elements, and the best way to realize it to cut down processes using automatic facilities. Packing container in logistics is like a facility. This study is intended to analyze reduction of costs, improvement of business process and reduction of working force through standardization of standardization, and logistics effects through improvement of environmental images in enterprises.

• Communications of the Korean Mathematical Society
• /
• v.34 no.1
• /
• pp.213-230
• /
• 2019

We construct new metric outer measures (multifractal analogues of the Hewitt-Stromberg measure) $H^{q,t}_{\mu}$ and $P^{q,t}_{\mu}$ lying between the multifractal Hausdorff measure ${\mathcal{H}}^{q,t}_{\mu}$ and the multifractal packing measure ${\mathcal{P}}^{q,t}_{\mu}$. We set up a necessary and sufficient condition for which multifractal Hausdorff and packing measures are equivalent to the new ones. Also, we focus our study on some regularities for these given measures. In particular, we try to formulate a new version of Olsen's density theorem when ${\mu}$ satisfies the doubling condition. As an application, we extend the density theorem given in [3].

• Journal of the Korean Mathematical Society
• /
• v.56 no.1
• /
• pp.25-37
• /
• 2019

Let G be a bipartite graph with (X, Y ) as its bipartition. Let B be a complete bipartite graph with a bipartition ($V_1$, $V_2$) such that $X{\subseteq}V_1$ and $Y{\subseteq}V_2$. A bi-packing of G in B is an injection ${\sigma}:V(G){\rightarrow}V(B)$ such that ${\sigma}(X){\subseteq}V_1$, ${\sigma}(Y){\subseteq}V_2$ and $E(G){\cap}E({\sigma}(G))={\emptyset}$. In this paper, we show that if G is a bipartite graph of order n with girth at least 12, then there is a complete bipartite graph B of order n + 1 such that there is a bi-packing of G in B. We conjecture that the same conclusion holds if the girth of G is at least 8.