• Clinical and Experimental Pediatrics
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• v.46 no.6
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• pp.606-609
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• 2003

Goltz syndrome(focal dermal hypoplasia) is a rare disorder characterized by ectodermal and mesodermal dysplasia described in 1962 by Goltz. In Korea, one case of Goltz syndrome was reported in 1994. The inheritance mode is mostly X-linked dominant. Skin abnormality is the most common manifestation including hypoplasia of the dermis. Skeletal involvement such as syndactyly, polydactyly, scoliosis, kyphosis and spina bifida occulta may be present, also ocular and dental abnormalities are reported. Radiologic findings are the osteopathy and striation of the long bone. We experienced a case of Goltz syndrome in a 9-year old female who was presented with right side hypotrophy, focal dermal hypoplasia, ocular(anidria, microcornea), dental(oligodontia, amelogenesis) and skeletal(syndactyly) abnormalities. Skin biopsy was performed and showed decreased expression of type I collagen gene with Northern blotting.

• Korean journal of applied entomology
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• v.31 no.3
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• pp.314-327
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• 1992

Insecticide resistance is a serious is a serious threat to IPM, resulting in various adverse effects not to mention the loss of yield in agriculture. One approach to counter the problem is the disruption of resistance mechanisms. This can be achieved by (1) compounds which show a negative correlation with resistance at the site of action, (2) specific metabolic inhibitors which serve as synergists, or (3) a certain combination of two insecticides producing a joint action. This approach, however, requires certain precautions for the side effects may cause an increase in toxicity to mammals. Owing to the recent advances in theoretical studies on resistance management employing computer simulation and mathematical models, a few principles to reduce the risk of development of resistance have been clarified. They are helpful in designing operational strategies with regard to, for instance, insecticide doses to be applied, mode of application, and choice and nature of the insecticide(s) to be used. For restoration of insecticide susceptibility of a resistant population, reintroduction of susceptible individuals to the resistant population is feasible when certain conditions are met. Natural enemies which developed resistance to insecticides can be an important component of IPM as has been shown in the pest management in apple orchards. After all, the implementation of a successful resistance management program depends upon cooperation between different sigments of the agricutural community. Although resistance is a preadaptive phenomenon, in some cases spontaneous loss of resistance does occur without contamination by susceptible individuals. The instability of resistance in these insects implies the possible existence of a switch machanism controlling the expression of resistance gene(s). Elucidation of such a mechanism may eventually provide us with a new technical approach with which we can combat the problem of insecticide resistance.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.1
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• pp.47-52
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• 2011

It is well known that stiffness of composites depends on layup sequence of CFRP(carbon fiber reinforced plastics) laminates because the layup of composite laminates influences their properties. Ultrasonic NDE of composite laminates is often based on the backwall echoes of the sample. A pair of such transducers was mounted in a holder in a nose-to-nose fashion to be used as a scanning probe on composites. Miniature potted angle beam transducers were used (Rayleigh waves in steel) on solid laminates of composites. Experiments were performed to understand the behavior of the transducers and the nature of the waves generated in the composite (mode, wave speed, angle of refraction). C-scan images of flaws and impact damage were then produced by combining the pitch-catch probe with a portable manual scanner known as the Generic Scanner ("GenScan"). The pitch-catch signal was found to be more sensitive than normal incidence backwall echo of longitudinal wave to fiber orientation of the CFRP composites, including low level porosity, ply waviness, and cracks. Therefore, it is found that the experimentally Rayleigh wave variation of pitch-catch ultrasonic signal was consistent with numerical results and one-side ultrasonic measurement might be very useful to detect the defects.

• Korean Journal of Optics and Photonics
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• v.16 no.6
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• pp.494-499
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• 2005

We have demonstrated a fiber short-wavelength filter with a good cut-off property using dissimilar dispersive properties between? a thermally expanded cored fiber and an external medium. Side-polishing is applied to coupling between the fiber and the external medium. The experimental results revealed that the bend edge wavelength can be adjusted by controlling the degree of core expansion. Futhermore, the sharpness of wavelength response? was significantly? improved by employing expanded core fiber instead of a conventional single mode fiber. Tuning range of the band edge wavelength exceeded 400 m based on thermo-optic effect of the external medium.

• Journal of the Korean Society of Safety
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• v.33 no.4
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• pp.1-7
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• 2018

This paper is analyzed for the thermal characteristics(1 year) of the 6 components(DC breaker, DC filter(including capacitor and discharge resistance), IGBT(Insulated gate bipolar mode transistor), AC filter, AC breaker, etc.) of a photovoltaic power generation-based PCS(Power conditioning system) below 20 kW. Among the modules, the discharge resistance included in the DC filter indicated the highest heat at $125^{\circ}C$, and such heat resulting from the discharge resistance had an influence on the IGBT installed on the rear side the board. Therefore, risk priority through risk priority number(RPN) of FMEA(Failure modes and effects analysis) sheet is conducted for classification into top 10 %. According to thermal characteristics and FMEA, it is necessary to pay attention to not only the in-house defects found in the IGBT, but also the conductive heat caused by the discharge resistance. Since it is possible that animal, dust and others can be accumulated within the PCS, it is possible that the heat resulting from the discharge resistance may cause fire. Accordingly, there are two options that can be used: installing a heat sink while designing the discharge resistance, and designing the discharge resistance in a structure capable of avoiding heat conduction through setting a separation distance between discharge resistance and IGBT. This data can be used as the data for conducting a comparative analysis of abnormal signals in the process of developing a safety device for solar electricity-based photovoltaic power generation systems, as the data for examining the fire accidents caused by each module, and as the field data for setting component management priorities.

• Computers and Concrete
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• v.6 no.1
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• pp.41-57
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• 2009

This paper presents the details of a novel external prestressing technique for strengthening of concrete members. In the proposed technique, transfer of external force is in shear mode on the end block thus creating a complex stress distribution and the required transverse prestressing force is lesser compared to conventional techniques. Steel brackets are provided on either side of the end block for transferring external prestressing force and these are connected to the anchor blocks by expansion type anchor bolts. In order to validate the technique, an experimental investigation has been carried out on post-tensioned end blocks. Performance of the end blocks have been studied for design, cracking and ultimate loads. Slip and slope of steel bracket have been recorded at various stages during the experiment. Finite element analysis has been carried out by simulating the test conditions and the responses have been compared. From the analysis, it has been observed that the computed slope and slip of the steel bracket are in good agreement with the corresponding experimental observations. A simplified analytical model has been proposed to compute load-deformation of the loaded steel bracket with respect to the end block. Yield and ultimate loads have been arrived at based on force/moment equilibrium equations at critical sections. Deformation analysis has been carried out based on the assumption that the ratio of axial deformation to vertical deformation of anchor bolt would follow the same ratio at the corresponding forces such as yield and ultimate. It is observed that the computed forces, slip and slopes are in good agreement with the corresponding experimental observations.

• The Journal of Korean Academy of Prosthodontics
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• v.31 no.3
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• pp.351-384
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• 1993

Complete denture occlusion must be developed to function efficiently and with the least amount of trauma to the supporting tissues. For the preservation of supporting tissues, it is imperative to reduce to a minimum the functional stress induced by dentures. The magnitude of the horizontal component of functional stress contributed by various occlusal teeth forms has not been studied. This study was aimed to investigate the influence of different occlusal teeth forms on the mode of distribution of the stresses in the mandibular tissue, and the displacement of lower dentures during the variant functional movement of mandible for this study three dimensional finite element analysis was used. FEM models were created using commercial software Super Sap for IBM 32 bit computer. The model was composed of 3380 brick elements and 4346 nodes. The results were as follows. 1. The magnitude of stress was similar between two models in centric occlusion, in the case of anatomic model, the stress was concentrated on the buccal side of alveolar ridge beneath the bicuspids. 2. During the protrusive movement, the increasing of stress from the posterior to anterior part of mandible was seen in the case of anatomic model. 3. During the lateral movement, the stress of anatomic model was greater than that of nonanatomic model. 4. The stress of anatomic model was concentrated on the anterior region of residual ridge during the lateral movement. 5. In the case of anatomic model the anterior part of denture was displaced severely at the centric and lateral position, but the denture of nonanatomic model was displaced minutely at the protrusive and lateral position.

• Journal of Electrical Engineering and Technology
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• v.2 no.1
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• pp.89-97
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• 2007

This paper presents a new circuit topology of active edge resonant snubbers assisted half-bridge soft switching PWM inverter type DC-DC high power converter for DC bus feeding power plants. The proposed DC-DC power converter is composed of a typical voltage source-fed half-bridge high frequency PWM inverter with a high frequency planar transformer link in addition to input DC busline side power semiconductor switching devices for PWM control scheme and parallel capacitive lossless snubbers. The operating principle of the new DC-DC converter treated here is described by using switching mode equivalent circuits, together with its unique features. All the active power switches in the half-bridge arms and input DC buslines can achieve ZCS turn-on and ZVS turn-off commutation transitions. The total turn-off switching losses of the power switches can be significantly reduced. As a result, a high switching frequency IGBTs can be actually selected in the frequency range of 60 kHz under the principle of soft switching. The performance evaluations of the experimental setup are illustrated practically. The effectiveness of this new converter topology is proved for such low voltage and large current DC-DC power supplies as DC bus feeding from a practical point of view.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.11 no.6
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• pp.96-103
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• 1997

This paper deals with the malfunction characteristics of the earth leakage circuit breakers(ELBs) applied by a lightning impulse voltage. In the cases of the regulation of KS C 4613 and the simulated circuits with surge protection devices, the dead operation characteristics of the ELBs against lightning impulse voltages were experimentally investigated and discussed. As a result, all the specimens(ELBs) used in this work have a cutoff performance of the lightning impulse voltage when the differential mode surges were injected at the input terminals of the ELBs owing to a surge absorber installed at the power source side of amplification circuit. Four kinds of the specimens have brought about malfunction in the condition of the lightning impulse dead operation test defined in KS C 4613, and the malfunction voltages are relatively high and are about 5-6.5[kV]. In the case of the simulated test circuit with surge protection devicesthree kinds of the ELBs have led to malfunction. Also the voltage level causing the malfunction of the ELBs is decreased by operation of surge protection devices, and it ranges from 3 to 5(kV).

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.127-130
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• 2005

Internal cities such as gray level been enclosed to building forest are paying a lot of efforts and expenses to change to green city that park and street tree get put together. By the example, 'GREEN CITY of PUSAN 21' progress to decorate army facilities like the park, and to plant street trees in several places of city plan in Pusan. And urban environment that big cities of advanced nation are agreeable is making in the large park and road street trees at several places in downtown. Because price of tree for the park is very expensive, tree management system was all-important. In this paper, Motes deliver the sensor information in each tree through radio sensor network by server side. This information can use in state grasping of tree, harmful insects courtesy call etc and this system design was suggested to inform to mode of life administration scholars.