• The Journal of Asian Finance, Economics and Business
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• 제7권11호
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• pp.55-65
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• 2020

The objective of this study is to investigate how investors in the Stock Exchange of Thailand practically trade in response to a magnitude of profits and losses, given a discussion of the widely well-known behavioral explanation, so called as the disposition effect. We provide empirical evidence of an existence of the V-shaped disposition effect, which has been recently found in several advanced equity markets. By adopting the methodology suggested by An's (2016) and Fama and Macbeth (1973), we document that stock return patterns in relation to aggregate unrealized gains and losses of investors are consistent with the V-shaped selling schedule, given an increase in unrealized gains and losses over the period of January 1996 to December 2015. The effect of unrealized gains is stronger than that of unrealized losses and this asymmetry underlies the existence of the V-shaped disposition effect in the Thai equity market. Interestingly, the effect of the V-shaped selling schedule is strongest over the short-term holding time horizon. Last but not the least, stocks for which investors have large unrealized gains and losses outperform in the following month and the long-short trading strategy, based on this premise, generates the average 1.7% monthly (equivalent to 20.0% per year) abnormal return.

• 한국주조공학회지
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• 제20권4호
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• pp.269-276
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• 2000

So far, the study on semi-solid process has been carried out to develop and research new advanced materials without some casting defects. In this study, A356 billets consisted of various dendritic shapes were prepared using electro-magnetic stirring process continuously. As-cast respectively has liquidus temperature of $625.6^{\circ}C$ and solidus temperature of $573.55^{\circ}C$ A356 slugs were reheated homogeneously at different temperatures of 580, 590 and $605^{\circ}C$, followed by squeezing in a mold insulated with applied pressures(0, 25, 50 and 70 MPa). In order to investigate on aging responce for casts, 50 MPa squeezed specimen among all specimens was prepared in aging treatments, which conditions are aging temperature of $160^{\circ}C$ and holding times of 0, 45, 90, 270, 360, 720, 1440 and 2880 min after solution treatment ($540^{\circ}C$ for 10 hr). SSM ingot with the output velocity of 150mm/min appeared more spheroidal shape and fine structure than that with the output velocity of 250 mm/min. According to increasing in reheating temperature, numbers of fatigue cycles, U.T.S and elongation increased at same time.

• 한국식품저장유통학회지
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• 제4권2호
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• pp.163-171
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• 1997

This study was undertaken to investigate changes m curve angle of Chinese cabbage blade during salting at various concentration(10, 15, 20, 25%) of salt to evaluated salting degree by curve angle during salting at 20$^{\circ}C$. Salt concentration of brine, the amount of water elution, salt penetration of the tissue(salt concentration of Chinese cabbage), weight loss and texture were investigated. Correlation relation between the above factors and curve angle were determined. The curve angles by method of holding the edge of the Chinese cabbage blade was measured. The curve angles of the mesophyll were proportional to salting time and salt concentration, but slope of line equation showed higher than that of mid-rib. The ideal method of salting evaluation by curve angle was MCA-MRC (the measuring curve angle of mid-rib C) at each concentration of salt. The results of curve angle when reached 3% salt of Chinese cabbage tissue calculated by MCA-MRC at 10, 15, 20 and 25% salting were 57$^{\circ}$, 43$^{\circ}$, 36$^{\circ}$, and 33$^{\circ}$, respectively. And salting times calculated by the same conditions were 19, 12.5, 9.1 and 4.4hours, respectively.

• 한국보건간호학회지
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• 제14권2호
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• pp.293-303
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• 2000

This study was designed to acknowledge the satisfaction levels of patients who have been treated in the emergency center. Specifically, to acknowledge the factors influencing patient's satisfaction levels related in the usage of emergency centers. Data was collected through patients who have used anyone of four emergency centers of university hospitals holding over 550 hospital beds, and located in Seoul. Questionnaires consisted of 31 questions. Cronbach's alpha was 0.94. Data analysis was executed with the SAS program by t-test, ANOVA and stepwise multiple regression. The results were summarized as follows. (1) The total average score for the level of satisfaction was 3.3. Regarding the service of doctors and nurses, the score was high. While the score regarding reception process, payment and second hand environment were relatively low. (2) There was a differentiation in the level of satisfaction according to the type of injured. Patents of industrial calamities had the highest level of satisfaction while patient injured by traffic accidents had the lowest level of satisfaction. (3) The factors that affect the level of satisfaction were presence of medical insurance, lapse time until treatment and the education level of the patient. Based on this, we will provide the basic data of satisfaction levels according to the characteristics of patients and the types of injuries for improvement of emergency treatment centers.

• 대한치과기공학회지
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• 제38권2호
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• pp.69-77
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• 2016

Purpose: This study was to evaluate the shear bond strength of ceramic fused to Ni-Cr alloy(Alophaloy) by heat treatment. Methods: The specimens were divided into 5 groups according to heat treatment conditions prior to porcelain application. Eighteen specimens from each group were subjected to the shear load a universal testing machine using a 0.1mm/min cross-head speed and two specimens from each group were observed with SEM and EDX line profile. Results: The observation of the oxide film on the metal surface by SEM photograph showed a coarsening with an increasing degassing hold time. The diffusion of metal oxide was observed farther from the opaque layer in the heat treated specimen than no heat treated specimen. The shear bond strength measured highest to A5(55.23MPa) in the 10min holding group and measured lowest from A1(24.38MPa) in the no heat treated group, and there was a significant difference(p<0.05). Conclusion: The shear bond strength of Ni-Cr alloy improved in the heat treatment compared to the no heat treatment specimen.

• 대한치과보철학회지
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• 제38권4호
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• pp.461-471
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• 2000

This study evaluated the effect of degassing on the ceramic bond strength of two Ni-Cr alloys under varying holding time at the upper limit temperature and atmospheric conditions. Metal specimens were divided into 5 groups for each alloy according to degassing conditions prior to porcelain application no degassing, degassing under vacuum without hold, degassing under vacuum with hold for 5 min. and 10 min. respectively at the upper limit temperature and degassing in air. Total number of metal ceramic specimens was eighty and each group had eight specimens. The ceramic bond strength was measured by four-point flexural test using Instron and the fractured surface was examined under SEM. The results obtained were as follows. 1. Degassing in air improved the ceramic bond strength of Ni-Cr alloys. 2. In degassing under vacuum, hold at the upper limit temperature was advantageous to the ceramic bonding of Ni-Cr alloys. 3. After ceramic metal bond test, metal surfaces were partially covered with the thin porcelain layer, and the cohesive failures in porcelain were predominant in groups showing higher ceramic bond strength.

• 한국해양공학회지
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• 제2권2호
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• pp.104-111
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• 1988

This paper deals with the micro-surface-cracks behavior on the unnotched smooth specimens of Type 304 stainless steel at $593^{\circ}C$ in air under creep and creep-fatigue conditions that have 10 mim and 1 min load holding times respectively. The behaviors of the micro-surface-cracks have been visualized by means of surface replica method and optical micro-photography. The quantitative characteristics of initiation, growth and coalescence of micro-surface-cracks have been investigated by observing and measuring the crack growth behaviors. some of the important results are as follows: Main crack initiates at grain boundary in the early stage(10 to 20%)of its life time and grows through coalescence and finally leads to fracture. The distribution of micro-surface-crack length, 2a, can be plotted against the composite Weibull distribution. The growth rate of the main crack can be plotted against the stress intensity factor, crack tip opering displacement and J integral.

• 한국세라믹학회지
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• 제54권5호
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• pp.395-399
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• 2017

The thermal properties and crystallization behavior of calcium phosphate glass fabricated using eggshell were examined. Nature eggshell has several impurities in the main component of $CaCO_3$. To manufacture calcium phosphate glass, washed eggshell was dissolved in aqua-regia while adding a solution of isopropyl alcohol, D. I. water and phosphoric acid. The calcined precursor was melted at $1000^{\circ}C$, and the glass ($T_g$ : $540^{\circ}C$) was crystallized at $620{\sim}640^{\circ}C$, which temperature range is relatively low compared to the crystallization temperature of other general types of calcium phosphate glass. The calcium phosphate glass using eggshell was successfully crystallized without any additional nucleating agents due to the multiple effects of impurities such as $Fe_2O_3$, $Al_2O_3$, SrO and $SiO_2$ in the eggshell. The main crystalline phase was ${\beta}-Ca(PO_3)_2$ and a biocompatible material, hydroxyapatite, was also observed. The crystallization process was completed under the condition of a holding time of only 1 h at the low temperature.

• 한국조경학회지
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• 제27권5호
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• pp.48-56
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• 2000

This study aims to find out the norms and principles reflected in the spatial organization of royal tombs in the Chosun Dynasty through the modern interpretation of traditional oriental philosophy theory. We examined the characteristics of royal tomb sites including Jeshil(Shrine), Hongjunmun, tomb mound, ponds, and attached buildings employing an analysis of the spatial formation and landscape. This study covered 36 tombs of kings and queens in the Chosun Dynasty. The entire layout of royal tombs, including annexed buildings, was informal in may cases. This was due to following the natural contour rather than adhering to certain philosophical principles. The royal tomb site is divided into three zones. Jeshil and pond constitute a space for living people, visitors. Secondly, the semi-scared space includes the space from Hongjunmun to the entrance to the Chungjaka. The last space is for the dead, from the back of Chungjakak to tomb mound. This is in line with the layout of palaces of the Chosun Dynasty which is characterized by "three gates and three zones": outer yard-court yard- back yard. The size of the space for holding memorial ceremonies, from Hongjunmun to the Chungjakak entrance, was set at 900m until the early Chosun Dynasty. Since that time the distance varied according to the land topography due to the influence of metaphysics. It can be summarized that the spatial organization of royal tombs in the Chosun Dynasty is based on the Confucianism value, the natural contour of the site, and inner spiritual value.ual value.

• 대한기계학회논문집
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• 제12권6호
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• pp.1296-1302
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• 1988

The study has been carried out under various experimental conditions to investigate mechanical properties by the transformation conditions of austempered low-alloy ductile cast iron. The amount of retained austenite and bainite after quenching was determined by the X-ray diffractometer and the point counting method and which the microstructure was investigated by the S.E.M. The mechanical properties of austempered low-alloy ductile cast iron can be varried over a comparatively wide range by changing the transformation conditions. During isothermal transformation of austenite in the bainite region, low-alloy ductile cast iron austempered at holding time of 40 minute has the maximum volume fraction(24%) of retained austenite in the cast iron matrix and which optimum values of mechanical properties correspond to the maximum amount of retained austenite, which falls with decreasing transformation temperature. The low values of both tensile strength and elongation in the initial stage of bainite transformation can be explained by premature fracture of tensile specimens and the tensile strength, hardness and elongation do not change considerably after a certain period. With a decreasing transformation temperature the tensile strength increase while the elongation decrease, especially the elongation has the maximum value at temperature $370^{\circ}C$.