• IE interfaces
• /
• v.14 no.3
• /
• pp.326-333
• /
• 2001

The purpose of this paper is to empirically investigate the relationships between market environments and technology strategy using the data gathered from Korean manufacturing firms. As the significant environmental factors influencing company's technology strategy, two sorts of market aspects are considered; market competition factor and technological dynamics factor. And companies are categorized with respect to the characteristics of market environments they are facing with. Then we seek to find the differences in the contents of technology strategy among the companies in different types of environments through statistical analysis. As a result, it is found that there exist significant relationships between the companies' technology strategy and the environments facing firms.

• Journal of Environmental Science International
• /
• v.7 no.6
• /
• pp.745-751
• /
• 1998

The well-mixed room model has been traditionally used to predict the concentrations of contaminants in indoor environments. However, this is inappropriate because the flow fields in many indoor environments distribute contaminants non-uniformly, due to imperfect air mixing. Thus, some means used to describe an imperfectly mixed room are needed. The simplest model that accounts for imperfect air mixing is a two-zone model. Therefore, this study on development of computer program far the two-zone model is carried out to propose techniques of estimating the concentration of contaminants in the room. To do this, an important consideration is to divide a room into two-zone, i.e. the lower and upper zone assuming that the air and contaminants are well mixed within each zone. And between the zones the air recirculation is characterized through the air exchange parameter. By this basic assumption, the equations for the conservation of mass are derived for each zone. These equations are solved by using the computational technique. The language used to develope the program is a VISUAL BASIC. The value of air exchange coefficient($f_12$) is the most difficult to forecast when the concentrations of contaminants in an imperfectly mixed room are estimated by the two-zone model. But, as the value of $f_12$ increases, the air exchange between each zone increases. When the value of $f_12$ is approximately 15, the concentrations in both zone approach each other, and the entire room may be approximately treated as a single well-mixed room. Therefore, this study is available for designing of the ventilation to improve the air quality of indoor environments. Also, the two-zone model produces the theoretical base which may be extended to the theory for the multi-zone model, that will be contributed to estimate the air pollution in large enclosures, such as shopping malls, atria buildings, atria terminals, and covered sports stadia.

• Journal of Institute of Control, Robotics and Systems
• /
• v.12 no.5
• /
• pp.457-463
• /
• 2006

Recently proposed control scheme for a stable teleoperation, which was based on two-port time-domain passivity approach[21], has been successful for a contact with high stiffness environments. However, we found several conservatisms during the contact with deformable environments and unconstrained motion. The two-port time-domain passivity controller was excessively dissipating energy even though it was not necessary for some cases of an unconstrained motion and soft contact. The main reason of those conservatisms was on the fact that the two-port time-domain passivity controller was activated without considering the amount of energy dissipation at the master and slave manipulators. Especially, the exclusion of the slave manipulator from the two-port was the dominant reason of the conservatisms. In this paper, we consider the amount of energy dissipation at slave manipulator for designing the time-domain passivity observer and controller. The measured interaction force between slave manipulator and environment allow the time-domain passivity observer to include the amount of energy dissipation at the slave manipulator. Based on the modified passivity observer, reference energy following method[24] is applied to satisfy the passivity condition in real-time. The feasibility of the developed methods is proved with experiments. Improved performance is obtained for an interaction with deformable environments and an unconstrained motion.

• Journal of ILASS-Korea
• /
• v.21 no.4
• /
• pp.184-194
• /
• 2016

Many industrial processes require reliable temperature measurements in harsh environments with high temperature, dust, humidity, and pressure. However, commercially-available conventional temperature measurement devices are not suitable for use in such conditions. This study thus proposes a reliable, durable two-color radiation thermometer (RT) for harsh environments that was developed by selecting the appropriate components, designing a suitable mechanical structure, and compensating environmental factors such as absorption by particles and gases. The two-color RT has a simple, compactly-designed probe with a well-structured data acquisition system combined with efficient LabVIEW-based code. As a result, the RT can measure the temperature in real time, ranging from 300 to $900^{\circ}C$ in extremely harsh environments, such as that above the burden zone of a blast furnace. The error in the temperature measurements taken with the proposed two-color RT compared to that obtained using K-type thermocouple readouts was within 6.1 to $1.4^{\circ}C$ at a temperature range from 200 to $700^{\circ}C$. The effects of absorption by gases including $CO_2$, CO and $H_2O$ and the scattering by fine particles were calculated to find the transmittance of the two wavelength bands of operation through the path between the measured burden surface and the two-color probe. This method is applied to determine the transmittance of the short and long wavelength bands to be 0.31 and 0.51, respectively. Accordingly, the signals that were measured were corrected, and the true burden surface temperature was calculated. The proposed two-color RT and the correction method can be applied to measure temperatures in harsh environments where light-absorbing gases and scattering particles exist and optical components can be contaminated.

• Journal of the Korea Society for Simulation
• /
• v.10 no.3
• /
• pp.15-30
• /
• 2001

Hybrid simulation may employ different types of simulation based on which models in different system types are developed. The simulation requires simulation time synchronization and data exchange between such simulators, which is called simulators interoperation. This paper develops such interoperable simulation environments for modeling and simulation of hybrid systems whose components consist of continuous and discrete event systems. The environments, one for centerized and the other for distribute, support interoperation between a discrete event simulator of DEVSim++ and a continuous simulator of MATLAB. The centerized environment, HDEVSim++, is developed by extending the sxisting DEVSim++ environment; the distributed environment, HDEVSimHLA, is developed using the HLA/RTl library. Verification of both environments is made and performance comparison between the two using a simple example is presented. .

• Proceedings of the IEEK Conference
• /
• 2003.07d
• /
• pp.1323-1326
• /
• 2003

CORBA has been a popular middleware, but recently Web Services has been emerging as a promising web middleware since it uses Internet established standards such as URL, HTTP, XML, and etc. CORBA uses IDL for describing CORBA object interface and Web Services uses WSDL for its description. Thus, in order to port or integrate CORBA objects into Web Services, one needs to understand the relationship between CORBA IDL and WSDL. In this paper, we analyze IDL and WSDL, and compare between two. It turns out that there exists a direct mapping between two, and that understanding operational environments and logic of two technologies is much more important in converting or integrating CORBA objects into Web services successfully.

• Journal of The Korean Association For Science Education
• /
• v.16 no.2
• /
• pp.217-225
• /
• 1996

Science-related attitudes, perceptions of science classroom environments, and their relationships were investigated for a sample of 535 primary and secondary school students. Two scales of the Test of Science-Related Attitudes and five scales of the Classroom Environment Scale(CES) were administered. Students' perceptions of preferred science classroom environments were also investigated using the same scales of the CES and compared with those of actual classroom environments. The results indicated the primary school students had the most positive attitudes on Enjoyment of Science Lesson and Career Interest in Science. They also had the highest scores on perceptions of actual classroom environments, while the high school students had the lowest scores. Regarding the relationships between science-related attitudes and perceptions of classroom environments, multiple correlations for the five scales of the CES were found to be significant(p<01). The scores of four scales-Involvement, Teacher Support, Order and Organization, Rule Clarity-are significantly correlated with the scores of Enjoyment of Science Lesson. Students' perceptions of preferred classroom environments on the four scales of the CES are significantly higher than those in actual environments. However, students' perceptions of actual environments on Task Orientation are similar to those of preferred environments, and are not significantly correlated with Enjoyment of Science Lesson. Educational implications are discussed.

• Journal of Biomedical Engineering Research
• /
• v.27 no.1
• /
• pp.14-21
• /
• 2006

As information technologies are developing, the improvement of the quality of life becomes worldwide issues. Especially, to improve the quality of life of a patient suffering intermittent diseases, in addition to the some portable equipments for measuring, analyzing, and notifying the status of the patients, methods of communication for seamless transmission of the measured data over to the remote site, such as an emergency center or a hospital, are required. In this paper, we address a seamless transmission of patient monitoring data such as ECG from a moving patient to a remote site, wherever the patient may be. We divide the whole environments into two wireless communication environments: an indoor one based on WLAN and an outdoor one based on CDMA cellular network in which the patient is assumed to move anywhere. We develop algorithms, implement them on a PDA-based hardware platform, and show some of the results for handover between the two environments in addition to the data transmission for each of the two environments.

• The Journal of Bigdata
• /
• v.1 no.2
• /
• pp.91-102
• /
• 2016

In traditional environments we have called the data life cycle DIKW, which represents data-information-knowledge-wisdom. In big data environments, on the other hand, we call it DIA, which represents data-insight-action. The difference between the two data life cycles results in new architecture of data resource management. In this paper, we study data resource management architecture for big data environments. Especially main components of the architecture are proposed in this paper.

• Fisheries and Aquatic Sciences
• /
• v.3 no.3_4
• /
• pp.180-187
• /
• 2000

Reproductive effort and spawning frequency of the two palaemonid prawns, Exopalaemon modestus and Palaemon gravieri, were investigated. In both embryos of the two species, egg size was larger in E. modestus than in P. gravien but for a given size, number of eggs (EN) was fewer in E. modestus. The statistical results revealed that there were significant differences in egg size and EN between the two species. E. modestus living in freshwater environments had larger and fewer offspring than P. gravieri inhabiting marine environments. These findings are consistent with predictions from r- and K-selections models. Reproductive effort (RE) also was higher in E. modestus, suggesting the possibility for E. modestus to invest larger amount of energy per individual offspring. In the two prawns the ovarian dry weight of females with eyed eggs was significantly higher than those with non-eyed eggs. This indicates that the ovarian maturation occurs during the period between the two embryonic stages, suggesting females being potentially of continuous breeding within a single reproductive period. In the both species brood loss did not occur during the incubation period.