• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.5
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• pp.1257-1263
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• 2003

The modified engineering methodology and the modified electronic circuit in classical ultrasonic principles were applied to ultrasonic aerosol nebulizer for inhalation toxicology study of cadmium aerosol. 1532.96ppm Cd nebulizing solution was used to generate cadmium aerosol for particle size analysis with the modifying source and inlet temperatures. The results of particle size analysis for cadmium aerosol were as following. The highest particle counting for source temperature 20℃ was 399.75 × 10² in inlet temperature 100℃ and particle diameter 0.75㎛. The highest particle counting for source temperature 50℃ was 399.70 × 10² in inlet temperature 50℃ and particle diameter 0.75㎛. The highest particle counting for source temperature 70℃ was 411.14 × 10² in inlet temperature 100℃ and particle diameter 0.75㎛. The ranges of geometric mean diameter were 0.74-0.79㎛ in source temperature 20℃, 0.65-0.72㎛ in source temperature 50℃, and 0.65-0.80㎛ in source temperature 70℃. The smallest geometric mean diameter was 0.65㎛ in source temperature 50, 70℃ and inlet temperature 20, 50℃, and the largest geometric mean diameter was 0.80㎛ in source temperature 70℃ and inlet temperature 100℃. The ranges of geometric standard deviation were 1.71-1.80 in source temperature 20℃, 1.27-1.61 in source temperature 50℃, and 1.27-2.29 in source temperature 70℃. The lowest geometric standard deviation was 1.27 in source temperature 50, 70℃ and inlet temperature 20, 50℃, and the highest geometric standard deviation was 2.29 in source temperature 70℃ and inlet temperature 100℃. Generated aerosol for cadmium inhalation toxicology study was polydisperse aerosol with the above geometric standard deviation 1.2. The ranges of mass median diameter(MMD) were 1.75-2.25㎛ in source temperature 20℃, 1.27-1.61㎛ in source temperature 50℃, and 1.27-2.29㎛ in source temperature 70℃. The smallest MMD was 1.27㎛ in source temperature 50, 70℃ and inlet temperature 20, 50℃, and the largest MMD was 2.29㎛ in source temperature 70℃ and inlet temperature 100℃. Cadmium chloride concentration in nebulizing solution affected the particle size and distribution of cadium aerosol in air. MMO for inhalation toxicology testing in OECD and EU is less than 3㎛ and EPA guidance is less than 4㎛. In our results, in source temperatures of 20, 50, 70℃, and inlet temperatures of 20, 50, 100, 150, 200, 250℃ were conformed to the those guidance.

• Korean Journal of Plant Tissue Culture
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• v.24 no.4
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• pp.239-256
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• 1997

Plants belonging to the category of 2n apomixis or agamospermy form embryos and seeds without the processes of normal meiosis and syngamy. Seeds produced in this way have identical genotype of their maternal parent. Three different types of agamospermy are recognized: diplospory, apospory, and adventitious (adventive) embryony. $F_1$ hybrid cultivars cannot be used as seed sources in the next ($F_2$) generation because this generation would be extremely variable as a result of genetic segregation. Hybrid vigor is also reduced in the $F_2$ generation. Therefore, parental stocks for hybrid seed production need to be maintained and cross must be continuously repeated. Agamospermic 2n apomixis would make it possible to fix the genotype of a superior variety so that clonal seeds faithfully representing that genotype could be continuously and cheaply produced independent of pollination. That is, $F_1$ hybrid seeds could be produced for many generations without loss of vigor or genotype alteration. Production of apomictic $F_1$ hybrid seed would be simplified because line isolation would not be necessary to produce seed or to maintain parental lines, and the use of male-sterile lines could be avoided. Overall, apomixis would enable a significant reduction in hybrid seed production costs. Additionally, the production of clonal seed is not only important for seed propagated crops, but also for the propagation of heterozygous fruit trees and timbers. Clonal seed would help avoid costly and time-consuming vegetative propagating methods that are currently used to ensure the large-scale production of these plants. Apomixis is scattered throughout the plant kingdom, but few important agricultural crops possess this trait Therefore, most research to date has centered on introgressing the trait of apomixis into agricultural crops such as wheat, maize, and some forage grasses from wild distant relatives by traditional cross breeding. The classical breeding approach, however is slow and often impeded by many breeding barriers. These problems could be surmounted by taking mutagenesis or molecular approach. Arabidopsis thaliana is a tiny sexually reproducing plant and is convenient in constructing and screening in molecular researches. Male-sterile mutants of Arabidopsis are particularly suitable genetic background for mutagenesis and screening for apomictic mutants. Molecular approaches towards isolating the genes controlling the apomictic process are feasible. Direct isolation of genes conferring apomixis development would greatly facilitate the transfer of this trait to wide variety of crops. Such studies are now in progress.

• Journal of Korean Society of Transportation
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• v.22 no.7 s.78
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• pp.107-117
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• 2004

The growing demand for customer-response, made-to-order manufacturing and satisfactory delivery are stimulating the importance of commercial fleet management problem. Moreover, the rapid transformation to the customer-oriented multi-frequency, relatively small fleet, such as home delivery and Perishable goods, requiring prompt delivery and advanced real-time operation of vehicle fleets. In this paper we consider the vehicle routing problem(VRP) to minimize delivery completion time which is equal to the time that last customer wait for the vehicle in fleet operation. The mathematical formulation is different from those for the classical VRP which is minimizing cost/distance/time by running vehicles in manager's point of view. The key aspect of this model is not considering the return time from the last customer to depot in every vehicle path. Thereby, the vehicle dispatcher can afford to dynamically respond to customer demand and vehicle availability. The customer's position concerned with minimizing waiting time that may be applied for the delivery of product required freshness or delivery time. Extensive experiments are carried out to compare the performance of minimizing delivery completion time by using the ILOG Solver which has the advantage of solving quickly an interim solution very near an optimal solution. The experimental results show that the suggested model can easily find near optimal solution in a reasonable computational time under the various combination of customers and vehicles.

• Journal of Soil and Groundwater Environment
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• v.12 no.5
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• pp.33-36
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• 2007

In recent years the convective-dispersive equation has been often discredited in predicting subsurface solute transport under field conditions due to presence of preferential flow paths. Kim et al. (2005) proposed a simple equation that can predict the breakthrough of solutes without excessive data requirements. In their Generalized Preferential Flow Model (GPFM), the soil is conceptually divided in a saturated "distribution layer" near the surface and a "conveyance zone" with preferential flow paths below. In this study, we test the model with previously published data, and compare it with a classical convective-dispersive model (CDM). With three parameters required-apparent water content of the distribution zone, and solute velocity and dispersion in the conveyance zone-GPFM was able to describe the breakthrough of solutes both through silty and sandy loam soils. Although both GPFM and CDM fitted the data well in visual, variables for GPFM were more realistic. The most sensitive parameter was the apparent water content, indicating that it is the determining factor to apply GPFM to various soil types, while Kim et al. (2005) reported that changing the velocity of GPFM reproduced solute transport when same soils were used. Overall, it seems that the GPFM has a great potential to predict solute leaching under field conditions with a wide range of generality.

• Journal of the Korean earth science society
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• v.26 no.6
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• pp.511-523
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• 2005

The purpose of this study is to analyze the 1st and 2nd Korea Earth Science Olympiad (KESO) items, in order to find informations to enhance item quality. To do this, internal and external item classification frameworks are developed. Item difficulty (P), discrimination index (DI), correlation, and reliability are estimated by using classical test theory. Generalizability is also estimated by applying the generalizability theory. The results of item classification are as follows: (1) ‘Geology’, ‘astronomy’ and ‘data analysis and interpretation’ are dominant in content and inquiry process domain, respectively. Nearly every item has textbook context. (2) There is no difference between the preliminary and final tests in terms of their thinking skills sections. (3) As a whole, the ratio of items with pictures is high in item representation. However, multiple-choice and short answer items are more common in preliminary competition, and essay type items are found more often in final competition. The ratio of simple items is high in middle school section and preliminary competition, but composite items are dominant in high school section and final competition. The findings of item analysis are as follows: (1) In the middle school section, P is low and DI is moderate. But in the high school section, there is a considerable differences between science high schools and other high schools in general. (2) The highest correlation is reported between the scores of meteorology domain and total score in middle school, whereas in high school astronomy domain and total score show the highest correlation. (3) General high school section show the highest Cronbach $\alpha$ and generalizability. (4) General high school section show acceptable generalizability coefficient (> 0.80), but middle and science high school section should increase the number of items to reach acceptable generalizability level.

• Journal of the Korean Geographical Society
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• v.39 no.5 s.104
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• pp.735-754
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• 2004

This paper provides an overview of political ecology, a body of theory that focuses on the links between political and economic inequality on the one hand, and environmental degradation on the other. Adopting a tripartite classification scheme that identifies three political ecology traditions -'classical', 'democratic' and 'poststructuralist'- the discussion shows the need for a move within the poststructuralist tradition away from a narrow and quasi-idealistic focus on discourse to a more robust philosophical engagement with ontological and epistemological issues grounded in Gilles Deleuze's development of Nietzschean materialism. From there. the author draws on numerous examples from Canada, and surveys the available literature on 'bioregionalism', a relatively new intellectual tradition evolved from the North American environmental social movements of the 1970s and 1980s. The so-called 'bioregional approach' stresses that administrative units need to reflect (rather than transect) eco-geographical and cultural features. Bioregionalism is described and assessed as a potential pragmatic research framework for geographers and other planners wishing to respond proactively to the call for a revamped, poststructuralist political ecology. The paper concludes that a bioregional approach to political ecology avoids the weaknesses identified by certain critics, provides scope for consideration of fundamental philosophical ideas, and as such, represents a practical development of a poststructuralist political ecology.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.12
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• pp.5013-5018
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• 2015

Background: Myeloproliferative neoplasms (MPNs) are clonal hematopoietic stem cell disorders characterized by proliferation of one or more myeloid lineages. Polycythemia vera (PV), essential thrombocythemia (ET) and primary myelofibrosis (PMF) are classical Philadelphia chromosome (Ph)-negative MPN that have a Janus Kinase 2 (JAK2) mutation, especially JAK2V617F in the majority of patients. The major complications of Ph-negative MPNs are thrombosis, hemorrhage, and leukemic transformation. Objective: To study clinical manifestations including symptoms, signs, laboratory findings, and JAK2V617F mutations of Ph-negative MPN (PV, ET and PMF) as well as their complications. Materials and Methods: All Ph-negative MPN (PV, ET and PMF) patients who attended the Hematology Clinic at Maharaj Nakorn Chiang Mai Hospital from January, 1 2003 through December, 31 2013 were retrospectively reviewed for demographic data, clinical characteristics, complete blood count, JAK2V617F mutation analysis, treatment, and complications. Results: One hundred and fifty seven patients were included in the study. They were classified as PV, ET and PMF for 68, 83 and 6 with median ages of 60, 61, and 68 years, respectively. JAK2V617F mutations were detected in 88%, 69%, and 100% of PV, ET and PMF patients. PV had the highest incidence of thrombosis (PV 29%, ET 14%, and PMF 0%) that occurred in both arterial and venous sites whereas PMF had the highest incidence of bleeding (PMF 17%, ET 11%, and PV 7%). During follow up, there was one ET patient that transformed to acute leukemia and five cases that developed thrombosis (three ET and two PV patients). No secondary myelofibrosis and death cases were encountered. Conclusions: Ph-negative MPNs have various clinical manifestations. JAK2V617F mutations are present in the majority of PV, ET, and PMF patients. This study confirmed that thrombosis and bleeding are the most significant complications in patients with Ph-negative MPN.

• Journal of the Korean Society of Costume
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• v.63 no.4
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• pp.84-100
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• 2013

Ancient Greece was a patriarchal society that distinguished gender roles between men and women. Although their costumes were composed of simple rectangular fabric without any technical complications in itself, the Greeks did try to express gender differences in their clothing. The final look of the Greek costume was dependent on the way the cloth draped onto its wearer as well as the wearer's identity. Greeks costume could just be seen as a rectangular fabric when it was not draped on a person's body. The purpose of this study is to examine how the gender differences were expressed in the ancient Greek drapery costume, which was made by using a completely different technical process, compared with the modern tailored costume. There are four elements of the costume that give the costume its formative shape, which are the wearer's body, the rectangular fabric (material as the first formative costume), the way the fabric is draped, and the final appearance as the second formative costume (the relationship between the wearer's body and the costume) and this study analyzes these elements individually. It is intended to analyze the gender characteristics and how each element appears in a different way from the perspective of Structuralism, an analytical method that considers a phenomenon as a total sum of the elements. Literature research was conducted and representative sculpture, painting and pottery, were used between the Archaic Period (B.C. 800~500) and the Classical Period (B.C. 500~323). The results show that the gender differences appear in each formative element of costume: First, the body was distinguished by the ancient Greek custom. The man's nudity was accepted while the woman's body was concealed. Second, in regards to the first formative costume, which was the rectangular fabric, men's were made with thick high quality wool because their involvement in outdoor activities meant that they needed clothes to stay warm, while the women wore clothes made of thin wool or hemp cloth, because their most of their activities were at home. Third, the way to drape the fabric shows the gender differences by changing the length of the clothing and its design ; men's short khiton was practical for big movement and at the same time the clothing exposed the man's body. The woman's doric khiton diversified its decoration by the size of the apotigma and by using the belt. Finally the second formative costume reflected the Greeks' social distinction between a man's body and a woman's body. The man's costume naturally exposed the man's body. On the other hand, the woman's long costume has a variety of shapes on the ground, that concealed her lower body, while the ornamental function was more accentuated than the man's costume. The gender differences expressed in Greek costume fundamentally reflected the point of view of the male and female body and their social roles in society.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.9
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• pp.881-889
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• 2015

Ocean thermal energy conversion is an organic Rankine cycle that generates power using the temperature difference between surface water and deep water. This study analyzes the thermodynamic efficiency of the cycle, which strongly depends on the working fluid and the cycle configuration. Cycles studied included the classical simple Rankine cycle, Rankine cycles with an open feedwater heater and an integrated regenerator, as well as the Kalina cycle. Nine kinds of simple refrigerants and three kinds of mixed refrigerants were investigated as the working fluids in this study. Pinch-point analysis that set a constant pinch-point temperature difference was applied in the performance analysis of the cycle. Results showed that thermodynamic efficiency was best when RE245fa2 was used as the working fluid with the simple Rankine cycle, the Rankine cycles with an open feedwater heater and an integrated regenerator, and when the mixing ratio of $NH_3/H_2O$ was 0.9:0.1 in the Kalina cycle. If the Rankine cycles with an open feedwater heater, an integrated regenerator, and the Kalina cycle were used for ocean thermal energy conversion, efficiency increases could be expected to be approximately 2.0%, 1.0%, and 10.0%, respectively, compared to the simple Rankine cycle.

• Steel and Composite Structures
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• v.36 no.5
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• pp.553-568
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• 2020

Steel-concrete composite structures have been extensively used in building, bridges, and other civil engineering infrastructure. Shear stud connectors between steel and concrete are essential in composite members to guarantee the effectiveness of their behavior in terms of strength and deformability. This study focuses on investigating the shear stiffness of headed studs embedded in several types of concrete with wide range of compressive strength, and their effects on the elastic behavior of steel-concrete composite girders were evaluated. Firstly, totally 206 monotonic push-out tests from the literature were reviewed to investigate the shear stiffness of headed studs embedded in various types of concrete (NC, HPC, UHPC etc.). Shear stiffness of studs is defined as the secant stiffness of the load-slip curve at 0.5V_u, and a formulation for predicting defined shear stiffness in elastic state was proposed, indicating that the stud diameter and the elastic modulus of steel and concrete are the main factors. And the shear stiffness predicted by the new formula agree well with test results for studs with a diameter ranging from 10 to 30 mm in the concrete with compressive strength ranging from 22.0 to 200.0MPa. Then, the effects of shear stiffness on the elastic behaviors of composite girders with different sizes and under different loading conditions were analyzed, the equations for calculating the stress and deformation of simply supported composite girders considering the influence of connection's shear stiffness were derived under different loading conditions using classical linear partial-interaction theory. As the increasing of shear stiffness, the stress and deflection at the most unfavorable section under partial connected condition tend to be those under full connected condition, but the approaching speed decreases gradually. Finally, the connector's shear stiffness was recommended for fully connection in composite girders with different dimensions under different loading conditions. The findings from present study may provide a reference for the prediction of shear stiffness for headed studs and the elastic design of steel-concrete composite girder.