• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.2
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• pp.48-56
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• 1995

The operating characteristics, such as, the threshold gain, lasing frequency, and longitudinal intensity profile, etc., of 1.55$\mu$m DFB laser diode with index and/or gain grating structures and with one side AR-coated mirror have been analyzed. From this analysis, the optimum design parameters have been shown that ${\Delta}{\Omega}$ (the phase difference between index grating and gain grating) is 0 or ${\pi}$, (xL)$_{r}$=1~3 and (xL)$_{i}$=0.5~0.9. It has been also shown that the modal selectivity and intensity uniformity of the DFB lasers with .DELTA..OMEGA.=0 are ~1.2 times better thatn those of the DFB lasers with ${\Delta}{\Omega}$= ${\pi}$.

• Journal of the Optical Society of Korea
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• v.9 no.2
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• pp.49-53
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• 2005

We report a new configuration of a reflection-type confocal scanning optical microscope system for measuring the refractive index profile of an optical waveguide. Several improvements on the earlier design are proposed; a light emitting diode (LED) at 650 nm wavelength instead of a laser diode (LD) or He-Ne laser is used as a light source for better index precision, and a simple longitudinal linear scanning and curve fitting techniques are adapted instead of a servo control for maintaining an optical confocal arrangement. We have obtained spatial resolution of 700 nm and an index precision of $2\times10^{-4}$. To verify the system's capability, the refractive index profiles of a conventional multimode fiber and a home-made four-mode fiber were examined with our proposed measurement method.

• Proceedings of the KIEE Conference
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• 1995.07b
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• pp.892-894
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• 1995

This paper deals with developmeant and application of coating thickness control system in hot dip galvanizing process. According to the line conditions, such as line speed, strip size and target coating weight, a predictive preset model sets the initial oprating conditions. Referring the zine coating informations from the gauge, mean coating value controller adjusts the chamber pressure and horizontal distance between strip and air knife, while coating deviation controller adjusts the lip gap profile of the air knife. All adaptive gains are interactively calculated by numeric models based on the theoretical analysis. The operating result with this system effectively reduces the coating deviation in transverse direction as well as in longitudinal direction.

• Structural Engineering and Mechanics
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• v.74 no.2
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• pp.255-266
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• 2020

The main requirements of modern welded metal structures are the load-carrying capacity (safety), fitness for production, and economy. The primary objective of attaching longitudinal stiffeners is to improve the buckling strength of relatively thin compression panels. This paper gives several comparisons for stiffened plates with different loadings (static, dynamic), different shape of stiffeners (flat, L-shape, trapezoidal), different steel grades, and different welding technologies (SMAW, GMAW, SAW), different costs to show the necessity of a combination of design, fabrication and economic aspects. Safety and fitness for production are guaranteed by fulfilling the design and fabrication constraints. The economy is achieved by minimizing the cost function. It is shown that the optimum sizes depend on the welding technology, the material yield stress, the profile of the stiffeners, the load cycles and the place of the production.

• Steel and Composite Structures
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• v.17 no.5
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• pp.641-665
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• 2014

This paper presents the analytical solutions for the size-dependent static analysis of the functionally graded (FG) beams with various boundary conditions based on the nonlocal continuum model. The nonlocal behavior is described by the differential constitutive model of Eringen, which enables to this model to become effective in the analysis and design of nanostructures. The elastic modulus of beam is assumed to vary through the thickness or longitudinal directions according to the power law. The governing equations are derived by using the nonlocal continuum theory incorporated with Euler-Bernoulli beam theory. The explicit solutions are derived for the static behavior of the transversely or axially FG beams with various boundary conditions. The verification of the model is obtained by comparing the current results with previously published works and a good agreement is observed. Numerical results are presented to show the significance of the nonlocal effect, the material distribution profile, the boundary conditions, and the length of beams on the bending behavior of nonlocal FG beams.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.10
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• pp.509-516
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• 2020

Since the 1960s, many rivers have been polluted and destroyed due to river repair projects for economic development and the covering of small rivers due to urbanization. Many studies have analyzed rivers using measured river topographic factors, but surveying is not easy when the flow rate changes rapidly, such as during a flood. In addition, the previous research has been mainly about the cross section of a river, so information on the longitudinal profile is insufficient. This research used informational entropy theory to obtain an equation that can calculate the average river slope, river slope, and river longitudinal elevation for a river basin in real time. The applicability was analyzed through comparison with measured data of a river's characteristic factors obtained from a river plan. The parameters were calculated using informational entropy theory, nonlinear regression analysis, and actual data. The longitudinal elevation entropy equation for each stream was then calculated, and so was the average river slope. All of the values were over 0.96, so it seems that reliable results can be obtained when calculating river characteristic factors.

• Journal of the Korean association of regional geographers
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• v.9 no.1
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• pp.66-76
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• 2003

Wetland is the ecotone between aquatic ecosystem and land ecosystem, and is much valuable in terms of ecology and economic. The stream wetland among inland fresh wetlands occupies the largest area but has been recognized as only a channel not a habitat. The purposes of this paper are to consider the characteristics of natural wetlands formed in the tributary flowing into the downstream reach of Nakdong River and to find its optimal management policy. Natural wetlands in the middle-size streams (2nd${\sim}$3rd order) are large marshlands, and were formed at the places from the mainstream away, because natural wetlands were formed in the reach of longitudinal profiles during the last glacial and the post-glacial period meet in disharmony. In order to conserve these natural wetlands effectively, we should compile the inventories of wetlands and make precise distribution maps. And we should do 'reverse-reclamation' which means the alteration of some farmlands reclaimed from natural wetland into natural wetland ecosystem, and develop the place or the space for wildlife education and ecotourism.

• The korean journal of orthodontics
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• v.49 no.6
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• pp.413-426
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• 2019

This study was performed to describe the longitudinal management of recurrent temporomandibular joint (TMJ) ankylosis from infancy to adulthood in perspective of surgical and orthodontic treatment. A 2-year-old girl was referred with chief complaints of restricted mouth opening and micrognathia due to bilateral TMJ ankylosis. For stage I treatment during early childhood (6 years old), high condylectomy and interpositional arthroplasty were performed. However, TMJ ankylosis recurred and symptoms of obstructive sleep apnea (OSA) developed. For stage II treatment during early adolescence (12 years old), gap arthroplasty, coronoidectomy, bilateral mandibular distraction osteogenesis, and orthodontic treatment with extraction of the four first premolars were performed. However, TMJ ankylosis recurred. Because the OSA symptoms reappeared, she began to use a continuous positive airway pressure device. For stage III treatment after completion of growth (20 years old), low condylectomy, coronoidectomy, reconstruction of the bilateral TMJs with artificial prostheses along with counterclockwise rotational advancement of the mandible, genioglossus advancement, and orthodontic treatment were performed. After stage III treatment, the amount of mouth opening exhibited a significant increase. Mandibular advancement and ramus lengthening resulted in significant improvement in the facial profile, Class I relationships, and normal overbite/overjet. The OSA symptoms were also relieved. These outcomes were stable at the one-year follow-up visit. Since the treatment modalities for TMJ ankylosis differ according to the duration of ankylosis, patient age, and degree of deformity, the treatment flowchart suggested in this report could be used as an effective guideline for determining the appropriate timing and methods for the treatment of TMJ ankylosis.

• The Journal of Industrial Distribution & Business
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• v.12 no.1
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• pp.31-46
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• 2021

Purpose: The purpose of the study is to analyze the characteristics of emotional intelligence and the variables related to emotional intelligence in a comprehensive manner. In addition, the study intends to present research trends and future research directions of emotional intelligence in a Korean context by analyzing the effects of emotional intelligence and its mechanisms. Research Design, Data, and Methodology: 77 KCI listed studies were selected for the analysis, and the research perspective of emotional intelligence, measurement instruments, empirical research and research methods were analyzed. In addition, research directions were suggested based on the analysis results. Results: The results of the analysis were as follows: First, previous researchers used the ability model of emotional intelligence the most. Second, Previous studies tended to focus on behavioral factors as dependent variables affected by emotional intelligence, in addition to attitudes, affection. Third, there were few studies on the antecedents of emotional intelligence, however, most studies dealt with the consequences of emotional intelligence. Fourth, few studies dealt with moderators between emotional intelligence and dependent variables. Fifth, on the research type, most studies were quantitative studies, however, a few of them were qualitative studies (Literature review, in-depth interview). Sixth, with regard to the analysis level, almost all studies were conducted on the individual level of emotional intelligence, and most studies featured a cross-sectional research design (longitudinal research design was rare). Conclusion: First, from the perspective of emotional intelligence, additional research should be focused on not only the ability model of emotional intelligence but also on the trait model or the mixed model in the future. Second, since emotional intelligence is a multidimensional construct, it is necessary to study the profile of emotional intelligence by employing people-centered as well as variable-centered methods. Third, with regard to empirical studies, additional research is needed with respect to not only the emotional intelligence of the subordinate, but also the emotional intelligence of the supervisor (leader) and the emotional intelligence of the group. Fourth, it is necessary to actively utilize not only cross-sectional design but also longitudinal design, and qualitative research and meta-analysis methods should also be adopted.

• Korean Journal of Social Welfare Studies
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• v.47 no.4
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• pp.255-280
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• 2016

This study examined sexual violence characteristics among the individuals who utilized victim support services provided by National Rape Crisis Intervention Centers in Korea. The study is the part of a Korean longitudinal study on sexual assault characteristics and its implications for post-abuse adjustments, which is supported by Korean Mental Health Technology R&D Project. Eleven national rape crisis centers nationwide and 29 NGO's participated in the study. The participating centers provided the data on sexual abuse characteristics from their standardized case management system. The cases were randomly selected from the system. Total of 1077 cases were gleaned from the system and utilized for this analysis. Results indicated that the abuse characteristics differed by victims' age (children, adolescent vs. adults) as well as relationship with perpetrator. We could identify six different profile groups based on the detailed violence characteristics. The results assured us of the importance to understand the detailed characteristics of sexual violence and the old notion that 'one size may not fit all'. The results from the profile analyses may have important implication for developing victim support programs and appropriately allocating agency resources according to the different profiles of the service users.