• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.11a
• /
• pp.160-160
• /
• 2008

In practical etching process, etch ant is sprayed on the metal-deposited panel through nozzles collectively connected to the manifold and that panel is usually composed of many PCB(printed circuit board)'s. The etching uniformity, the difference between individual PCB's on the same panel, has become one of most important features of etching process. In this paper, the prediction of nozzle trajectory has been performed by the combination of algebraic formula and numerical simulation. With the pre-determined geometrical factors of nozzle distribution, the trajectories of individual nozzles were predicted with the change of process operational factors such as panel speed, nozzle swing frequency and so on. As results, two dimensional distribution of impulsive force of etchant spray which could be considered as a key factor determining the etching performance have been successfully obtained. Though only qualitative prediction of etching uniformity have been predicted by the process developed in this study, the expansion to the quantitative prediction of etching uniformity is expected to be apparent by this study.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.42 no.1
• /
• pp.121-132
• /
• 2018

Recent beauty trends focus on suitability to individual features. A personal color system is a recent aesthetic concept that influences color make up and coordination. However, a personal color concept has several weaknesses. For example, type classification is qualitative and not quantitative because its measuring system is a sensory test with no industry standard of personal color system. A quantitative personal color type classification model is the purpose of this study, which can be a solution to above problems. This model is a kind of mapping system in a 3D Cartesian coordinate system which has own axes, Value, Saturation, and Yellowness. The cheek color of the individual sample is also independent variable and personal color type is a dependent variable. In order to construct the model, this study conducted a colorimetric survey on a 993 sampling frequency of Korean women in their 20s and 30s. The significance of this study is as follows. First, through this study, personal color system is established on quantitative color space; in addition, the model has flexibility and scalability because it consisted of independent axis that allows for the inclusion of any other critical variable in the form of variable axis.

• Journal of applied mathematics & informatics
• /
• v.29 no.3_4
• /
• pp.529-546
• /
• 2011

A deterministic tuberculosis model for theoretically assessing the potential impact of the combined effects of case detection in the presence of treatment is formulated. The qualitative features of its equilibria are analyzed and it is found that the disease-free equilibrium may not be globally asymptotically stable when the reproduction number is less than unity. This disease threshold number is further used to assess the impact of active TB case finding alone and in conjunction with treatment. A critical threshold parameter ${\Theta}$ say for which case detection will have a positive impact is derived. Using the Centre Manifold theory, the model may exhibit the phenomenon of backward bifurcation (coexistence of a locally stable endemic equilibrium with a stable disease-free equilibrium) when the reproduction number is less than unity. It is shown that the possibility of backward bifurcation occurring decreases with increase case detection. Graphical representations suggest that increase in case finding accompanied by treatment of detected TB cases, result in a marked decrease of TB cases (both latent and active TB).

• Journal of Korea Multimedia Society
• /
• v.20 no.7
• /
• pp.1113-1128
• /
• 2017

This study was practiced in order to develop a textbook to improve early childhood teachers' ability to use multimedia required by kindergartens and to examine its effects. First, investigation of the status of multimedia application of early childhood teachers in kindergartens was done along with looking through their attitude and anxiety. The expertise and the multimedia education was required in early childhood education and curriculum. As a result, 15 categories and 50 subcategories under 4 themes were drawn through the procedures of qualitative analysis. The conclusions obtained through this study were the following: First, the education for multimedia application related to the tasks required in kindergartens is needed instead of the common education for multimedia application, to improve the ability to use multimedia for early childhood teachers. Second, multimedia education based on visual theory for the purpose of early childhood education, rather than common features-centered multimedia education, is helpful for the improvement of early childhood teachers' ability to use multimedia. Finally, the improvement of early childhood teachers' ability to use multimedia will be a chance to provide children with a better educational environment.

• Journal of Korean Library and Information Science Society
• /
• v.43 no.3
• /
• pp.49-77
• /
• 2012

The purpose of this study is to investigate the values and meanings of university libraries and library catalog in the learning activities of Korean college students. Discussed in details are unique features in their library use behavior and catalog search behavior, and critical factors influencing their behavioral characteristics. A qualitative approach was employed for data collection and analysis. Intensive interviews were conducted with 30 students, also utilized was tight and close observation of their library search behavior. The result of this study is on identifying the underlying reasons why Korean students use their libraries and catalogs in a passive and limited manner.

• Journal of Information Technology Services
• /
• v.7 no.3
• /
• pp.159-174
• /
• 2008

The purpose of this study was to introduce a case that used web2.0 techniques to overcome the limitations of current DACUM method. For the purpose, firstly, we summarized the characteristics and limitations of current DACUM as a method to develop an occupational curriculum. The summary indicated that the results of DACUM process are likely to be influenced by the selection procedure of out-performers. In addition, current DACUM method is difficult to be adapted to big organizations, difficult to reflect rapidly changing society, and lack of qualitative review for the findings. To overcome these limitations, Seoul city designed a transformed DACUM method based on web2.0 techniques. The most outstanding features of the transformed DACUM method were web-based peer review systems to validate the findings of DACUM workshop. We concluded that the transformed DACUM method was proper to big size organizations faced with rapid changes and some organizations with special needs to establish their training systems based on the results of job analysis. Finally, we discussed several practical tips for the Seoul city's method.

• Proceedings of the KOSOMBE Conference
• /
• v.1997 no.11
• /
• pp.280-283
• /
• 1997

Human cervical spine has to protect the neural components and vascular structures. Also, it must have the flexibility afforded by an extensive range of motion to integrate the head with the body and environment. Because of these two-sided features, human cervical spine has very complicated shapes and their injury mechanisms are not fully understood yet. We have developed analytical model of human CS by using the finite element method. The model has been verified with in vivo and in vitro experimental results. From the qualitative analysis of simulation results, we were able to explain some of the fundamental mechanisms of neck pain. Further more, this FE model of human CS can be used as an analytical tool or biomechanical design of the clinical device and safety restraints.

• Journal of Information Processing Systems
• /
• v.16 no.5
• /
• pp.1214-1222
• /
• 2020

Pervasive augmented reality (AR) technology can be used to efficiently search for the required information regarding products in stores through text augmentation in an Internet of Things (IoT) environment. The evolution of context awareness and image processing technologies are the main driving forces that realize this type of AR service. One of the problems to be addressed in the service is that augmented objects are fixed and cannot be replaced efficiently in real time. To address this problem, a real-time mobile AR framework is proposed. In this framework, an optimal object to be augmented is selected based on object similarity comparison, and the augmented objects are efficiently managed using distributed metadata servers to adapt to the user requirements, in a given situation. To evaluate the feasibility of the proposed framework, a prototype system was implemented, and a qualitative evaluation based on questionnaires was conducted. The experimental results show that the proposed framework provides a better user experience than existing features in smartphones, and through fast AR service, the users are able to conveniently obtain additional information on products or objects.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2002.11a
• /
• pp.116-119
• /
• 2002

A different route to the synthesis of $Eu^{3+}$ - activated matrices such as $YAlO_{3}$ and $GdAlO_{3}$ and luminiscent properties of these compounds, were studied. The new route (Combustion method) consist of the redox reactions between the respective metal nitrates and urea in a preheated furnace at ${500^{\circ}C}$. The Phosphor thus obtained were then heated at ${1000^{\circ}C}$ for 2-3 hours to get better luminiscent properties. The incorporation of $Eu^{3+}$ activator in these phosphors were checked by luminiscence investigations. Scanning electron microscopy (SEM) studies were carried out to understand surface morphological features and the particle size. X-ray energy dispersive analysis (EDAX) was also performed for the qualitative analysis of the phosphors.

• Korean System Dynamics Review
• /
• v.4 no.1
• /
• pp.69-91
• /
• 2003

Using qualitative methods hinged on urban dynamics models, the paper addresses major issues concerned with new administrative capital construction. It tries to summarize the existing debates on new administrative capital construction and reinterpret diverse interacting factors in terms of reinforcing or balancing feedback structure. The paper suggests that understanding up on the dynamic mechanism imbedded in circular causal loop diagrams is the key to set up appropriate proposals and action plans for the new administrative capital, as they would reveal complicated linkages between the Capital Region and the rest, in addition to the urban dynamic of new administrative capital. In the same context, the paper can confirm similar features reflected in the relocation of capital functions at Canberra, Australia and Berlin, Germany. It has paid special attention to the fact that both Australian and German governments altogether stress the positive feedback loops as they have overcome unprecedented political confrontation among rival cities: Basically, they have encouraged gives-and-takes among major stake-holders. These research findings indicate that the future of new administrative capital construction depends on consensus buildings that can accommodate socio-economic and territorial changes between pros and cons. Although further researches and validations are needed, the system approach presented in this paper could assist Korean decision-makers in developing robust and responsive policy initiatives under uncertainties.