• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.116-122
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• 2021

This study quantitatively evaluated the performance improvement of a circular reinforced concrete pier under dynamic load with strengthening using a steel plate. Various three-dimensional elements were applied using the finite element program ABAQUS. The analytical parameters included the ratios of the steel cover length to the pier's total height and the ratios of the steel cover thickness to the pier diameter for inelastic-nonlinear analysis. The lower part of the pier had fixed boundary conditions, and lateral repetitive loads were applied at the top of the pier. The pier was investigated to evaluate the dynamic performance based on the load-displacement curve, stress-strain curve, ductility, energy absorption capability, and energy ratio. The yield and ultimate loads of piers with steel covers increased by 3.76 times, and the energy absorption capability increased by 4 times due to the confinement effects caused by the steel plate. A plastic hinge part of the column with a steel plate improved the ductility, and the thicker the steel plate was, the greater the energy absorption capacity. This study shows that the reinforced pier should be improved in terms of the seismic performance.

• Journal of the Korean Geotechnical Society
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• v.25 no.6
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• pp.5-16
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• 2009

The is study is to evaluate the small strain shear modulus ($G_{max}$) of Busan clay using in-situ penetration tests. A series of dilatometer tests (DMT) and piezocone penetration tests (CPTu) are performed at Busan newport and Noksan sites, and hybrid oedometer tests are also carried out on the specimens obtained from both sites. The $G_{max}$ is evaluated from the shear wave velocity ($V_s$) measured by the bender elements installed at the boundary of oedometer cell. By analyzing these data, the relationship of $G_{max}$ and state variables, such as confined stress and void ratio, is developed. The analysis of lab and in-situ test results reveals that the ratio of $G_{max}$ to $q_t$ is inversely proportional to the plasticity index while the ratio of $G_{max}$ to $E_D$ has a linear relationship with ($I/I_D$)$(p_a/{\sigma}'_v)^{0.5}$. Two correlations suggested in this study, based on CPT and DMT results, appear to provide reasonable predictions of the small strain shear modulus.

• Journal of Physiology & Pathology in Korean Medicine
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• v.16 no.1
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• pp.32-44
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• 2002

Gu-Chang is a disorder characterized by recurring ulcers confined to the oral mucosa. Despite much clinical and research attention, the causes remain poorly understood. In this paper, we will compare Gu-Chang with Recurrent Aphthous Stomatitis(RAS) in order to know what is the similiarity between Gu-Chang and RAS. So we will arrange various oriental and western medical literatures which are important. As a result of arrangement of the causes, symptoms and therapys of Gu-Chang, we can conclude through the studies as follows. 1. The etiologies of Gu-chang are following. In the Sthenia syndrome, there are evil heat of external factor, heat of heart and spleen, insomnia, heat of upper warmer, stress and diet, heat of lung and heart, excessive heat of upper warmer, inappropriate food intake, heat conveyance of organ, heat of stomach merdian, moistured heat of spleen and stomach and stasis of liver energy. In the Asthenia syndrome, there are deficiency of stomach energy, deficiency of upper warmer leading to heat, deficiency of middle warmer leading to cold, deficiency of lower warmer leading to heat, deficiency of middle energy, deficiency of blood, decreased fire and deficiency of soil, yin fire of lower warmer, deficiency of heart yin, deficiency of spleen yin and deficiency of qi and blood. 2. In western medicine the causes of RAS is presumed as local, microbial, systemic, nutritional, genetic, immunologic factors. 3. Once Gu-chang is compared with RAS, in the deficiency of yin leading to hyperactivity of fire, deficiency of yin leading to floating of fire and stasis of liver energy, recurring of Gu-chang is similar to RAS. Although recurring of Gu-chang due to tripple warmer of excessive fire has no recurrance, since there are the degree of Pain, site of lesion, dysphagia etc, it is similar to major RAS. It is may be believed that Sthenia Gu-chang is similar to major RAS, shape of recurring, site of lesion, degrree of Pain and white color of Asthenia Gu-chang are similar to minor RAS, but there is no similarity concerning herpes RAS in the literatures that describe the symptoms. 4. Generally, the treatment of Gu-chang is divided into Asthenia and Sthenia Syndrome. The method of cure to Sthenia syndrome is heat cleaning and purge fire, Asthenia syndrome is nourish yin to lower and adverse rising energy and strength the middle warmer and benefit vital energy. 5. Following is the medication for Sthenia syndrome. Heat of heart and spleen is Do Jok San, Yang Gyek San, Juk Yup Suk Go Tang, evil heat of external factor is Yang Gyek San Ga Gam, Stasis of liver energy is Chong Wi Fae Dok Yum, moistured heat of spleen and stomach is Chong Gi Sam Syep Tang. The medication for Asthenia Syndrome is following. Deficiency of upper warmer leading to heat is Bo Jung Ik Gi Tang, deficiency of middle warmer leading to cold is Bu Ja Lee Jung Tang, deficiency of lower warmer leading to heat is Yuk Mi Ji Hwang Tang, deficiency of yin leading to hyperactivity of fire is Ji Baek Ji Hwang Hwan, deficiency of yin leading to floating of fire is Lee Jung Tang Ga Bu Ja Medicine for external use were Yang Suk San, Boo Wyen San, Rok Po San, Yoo Hwa San ate. 6. In western medicine, there is no specific treatment for RAS, and management strategies depend on dinical presentation and symptoms and includes antibiotics, oral rinses, glucocorticoids, immunomodulatory drugs, vitamines, analgesics, laser and antiviral agents.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.15 no.2
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• pp.51-61
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• 2010

Surface particulate organic carbon (POC) concentration was measured in the Northeastern Gulf of Mexico on 9 cruises from November 1997 to August 2000 to investigate the seasonal and spatial variability related to synchronous remote sensing data (Sea-viewing Wide Field-of-view Sensor (SeaWiFS), sea surface temperature (SST), sea surface height anomaly (SSHA), and sea surface wind (SSW)) and recorded river discharge data. Surface POC concentrations have higher values (>100 $mg/m^3$) on the inner shelf and near the Mississippi Delta, and decrease across the shelf and slope. The inter-annual variations of surface POC concentrations are relatively higher during 1997 and 1998 (El Nino) than during 1999 and 2000 (La Nina) in the study area. This phenomenon is directly related to the output of Mississippi River and other major rivers, which associated with global climate change such as ENSO events. Although highest river runoff into the northern Gulf of Mexico Coast occurs in early spring and lowest flow in late summer and fall, wide-range POC plumes are observed during the summer cruises and lower concentrations and narrow dispersion of POC during the spring and fall cruises. During the summer seasons, the river discharge remarkably decreases compared to the spring, but increasing temperature causes strong stratification of the water column and increasing buoyancy in near-surface waters. Low-density plumes containing higher POC concentrations extend out over the shelf and slope with spatial patterns and controlled by the Loop Current and eddies, which dominate offshore circulation. Although river discharge is normal or abnormal during the spring and fall seasons, increasing wind stress and decreasing temperature cause vertical mixing, with higher surface POC concentrations confined to the inner shelf.

• Journal of the Korean Wood Science and Technology
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• v.2 no.2
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• pp.8-12
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• 1974

1. If one unity is given to the prongs whose ends touch each other for estimating the internal stresses occuring in it, the internal stresses which are developed in the open prongs can be evaluated by the ratio to the unity. In accordance with the above statement, an equation was derived as follows. For employing this equation, the prongs should be made as shown in Fig. I, and be measured A and B' as indicated in Fig. l. A more precise value will result as the angle (J becomes smaller. $CH=\frac{(A-B') (4W+A) (4W-A)}{2A[(2W+(A-B')][2W-(A-B')]}{\times}100%$ where A is thickness of the prong, B' is the distance between the two prongs shown in Fig. 1 and CH is the value of internal stress expressed by percentage. It precision is not required, the equation can be simplified as follows. $CH=\frac{A-B'}{A}{\times}200%$ 2. Under scheduled drying condition III the kiln, when the weight of a sample board is constant, the moisture content of the shell of a sample board in the case of a normal casehardening is lower than that of the equilibrium moisture content which is indicated by the Forest Products Laboratory, U. S. Department of Agriculture. This result is usually true, especially in a thin sample board. A thick unseasoned or reverse casehardened sample does not follow in the above statement. 3. The results in the comparison of drying rate with five different kinds of wood given in Table 1 show that the these drying rates, i.e., the quantity of water evaporated from the surface area of I centimeter square per hour, are graded by the order of their magnitude as follows. (1) Ginkgo biloba Linne (2) Diospyros Kaki Thumberg. (3) Pinus densiflora Sieb. et Zucc. (4) Larix kaempheri Sargent (5) Castanea crenata Sieb. et Zucc. It is shown, for example, that at the moisture content of 20 percent the highest value revealed by the Ginkgo biloba is in the order of 3.8 times as great as that for Castanea crenata Sieb. & Zucc. which has the lowest value. Especially below the moisture content of 26 percent, the drying rate, i.e., the function of moisture content in percentage, is represented by the linear equation. All of these linear equations are highly significant in testing the confficient of X i. e., moisture content in percentage. In the Table 2, the symbols are expressed as follows; Y is the quantity of water evaporated from the surface area of 1 centimeter square per hour, and X is the moisture content of the percentage. The drying rate is plotted against the moisture content of the percentage as in Fig. 2. 4. One hundred times the ratio(P%) of the number of samples occuring in the CH 4 class (from 76 to 100% of CH ratio) within the total number of saplmes tested to those of the total which underlie the given SR ratio is measured in Table 3. (The 9% indicated above is assumed as the danger probability in percentage). In summarizing above results, the conclusion is in Table 4. NOTE: In Table 4, the column numbers such as 1. 2 and 3 imply as follows, respectively. 1) The minimum SR ratio which does not reveal the CH 4, class is indicated as in the column 1. 2) The extent of SR ratio which is confined in the safety allowance of 30 percent is shown in the column 2. 3) The lowest limitation of SR ratio which gives the most danger probability of 100 percent is shown in column 3. In analyzing above results, it is clear that chestnut and larch easly form internal stress in comparison with persimmon and pine. However, in considering the fact that the revers, casehardening occured in fir and ginkgo, under the same drying condition with the others, it is deduced that fir and ginkgo form normal casehardening with difficulty in comparison with the other species tested. 5. All kinds of drying defects except casehardening are developed when the internal stresses are in excess of the ultimate strength of material in the case of long-lime loading. Under the drying condition at temperature of $170^{\circ}F$ and the lower humidity. the drying defects are not so severe. However, under the same conditions at $200^{\circ}F$, the lower humidity and not end coated, all sample boards develop severe drying defects. Especially the chestnut was very prone to form the drying defects such as casehardening and splitting.