• Maxillofacial Plastic and Reconstructive Surgery
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• v.30 no.5
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• pp.480-488
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• 2008

Orthodontists often treat cases which are difficult to treat with conventional orthodontics. In such cases, it could be treated with surgical procedures with the help of an oral surgeon. Especially, transverse deficiency of the mandible can be corrected by widening the transverse width of mandibular symphysis, using distraction osteogenesis. Transverse widening of mandibular sympysis is known as a safe treatment but still complications could occur during the treatment. We are reporting some complications of cases that mandibular symphysis transverse widening were applied. Some cases showed complications because of the inappropriate osteotomy line. Since straight vertical osteotomy line was inclined to the left, only the left bony segment was likely to expand. According to bio-mechanical considerations, it will be better to perform a step osteotomy, cutting the eccentric area of the alveolar crest and the centric area of the basal symphyseal area. Complications could also occur by the failure of the distraction device. The tooth borne distraction device was attached on the lingual side of the tooth with composite resin. During the distraction period, it was impossible to obtain appropriate distraction speed and rhythm because of frequent fall off of the distraction device. Therefore, distraction device should be attached firmly with orthodontic band or bone screw, etc. Tooth mobility increasement could also occur as a complication. 'Walking teeth phenomenon' was observed during the distraction period, showing severe teeth mobility and pain during mastication. These symptoms fade out during the consolidation period. Since the patient could feel insecure and uncomfortable, it should be notified to the patient before the procedure. Finally, alveolar crestal bone loss could occur. Alveolar crestal bone loss occurred because of lack of distraction device firmness and teeth trauma caused by lower lip biting habit. Therefore, adequate firmness of the distraction device and habit control will be needed.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.15 no.6
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• pp.122-128
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• 2016

The Biosensor biosensor pattern was developed by via an EHD (electro-hydro-dynamics (EHD) patterning process that was performed under atmospheric pressure at room temperature in a single step. The drop diameter was smaller than nozzle diameter and applied high viscosity conductive ink was applied in the EHD patterning method to provide a clear advantage over the piezo and thermal inkjet printing techniques. The Biosensor's biosensor's micro electrode pattern was printed by via a continuous EHD patterning method using 3three- type types of control parameters parameter (input voltage, patterning speed, nozzle pressure). High viscosity (1000 cps) conductive ink with 75 wt% of silver nanoparticles was used for experimentation. The incremental result of impedance of biosensor impedance was measured between the antibody ($10ug{\mu}g/ml$) to spore (0.1 ng/ml, 10 ng/ml, and $1ug{\mu}g./ml$) reaction at frequency 493 MHz frequency.

• Journal of Microbiology and Biotechnology
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• v.23 no.6
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• pp.864-871
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• 2013

The recombinant strain P. pastoris GS115-lccC was used to produce laccase with high activity. Factors influencing laccase expression, such as pH, methanol concentration, copper concentration, peptone concentration, shaker rotate speed, and medium volume were investigated. Under the optimal conditions, laccase activity reached 12,344 U/L on day 15. The recombinant enzyme was purified by precipitating and dialyzing to electrophoretic homogeneity, and was estimated to have a molecular mass of about 58 kDa. When guaiacol was the substrate, the laccase showed the highest activity at pH 5.0 and was stable when the pH was 4.5~6.0. The optimal temperature for the laccase to oxidize guaiacol was $60^{\circ}C$, but it was not stable at high temperature. The enzyme could remain stable at $30^{\circ}C$ for 5 days. The recombinant laccase was used to degrade chlorpyrifos in several laccase/mediator systems. Among three synthetic mediators (ABTS, HBT, VA) and three natural mediators (vanillin, 2,6-DMP, and guaiacol), vanillin showed the most enhancement on degradation of chlorpyrifos. Both laccase and vanillin were responsible for the degradation of chlorpyrifos. A higher dosage of vanillin may promote a higher level of degradation of chlorpyrifos, and the 2-step addition of vanillin led to 98% chlorpyrifos degradation. The degradation of chlorpyrifos was faster in the L/V system ($k_{obs}$ = 0.151) than that in the buffer solution ($k_{obs}$ = 0.028).

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.2
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• pp.166-174
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• 2014

Fuel injection pressure has steadily increased in diesel engines for the purpose of improving fuel efficiency and cleaning exhaust gas, but it has now reached a point, where the cost for higher pressure does not warrant additional gains. Common rail systems on modern diesel engines have fuel pumps that are mechanically driven by crankshaft. The pumps actually house two pumping module inside: a low pressure pump component and a high pressure pump component. Part of the fuel compressed by the low pressure component returns to the tank in the process of maintaining the pressure in the common rail. Since the returning fuel represents pumping loss, fuel economy improves if the returned fuel can be eliminated by using a properly controled electrical fuel pump. As the first step in developing an electrical fuel pump the fuel supply system on a 6 liter diesel engine was modeled with AMESim to analyze the workload and the fuel feed rate of the injection pump, and the results served as basis for selecting a suitable servo motor and a reducer to drive the pump. A motor controller was built using a DSP and a program which controls the common rail pressure using a proportional control method based on the target fuel pressure information from the engine ECU. A test rig to evaluate performance of the fuel pump is implemented and used to show that the newly developed electrically driven fuel pump can satisfy the fuel flow demand of the engine under various operating conditions when the rotational speed of the pump is adequately controlled.

• Restorative Dentistry and Endodontics
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• v.27 no.3
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• pp.257-269
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• 2002

Objective : The purpose of this study was to evaluate the resin infiltration into dentin of one-bottle adhesive systems and self-etching primer bonded to Class V cavities using confocal laser scanning microscope(CLSM). Material and Methods : Forty Class V cavities were prepared from freshly extracted caries-free Human teeth. These teeth were divided into two groups based on the presence of cervical abrasion: Group I, cervical abrasion : Group II, wedge-shaped cavity preparation. Resin-dentin interfaces were produced with two one-bottle dentin bonding systems-ONE COAT BOND(OCB; Coltene$^R$) and Syntac$^R$SPrint$^{TM}$(SS; VIVADENT)-, one self-etching priming system-CLEARFIL$^{TM}$ SE BOND (SB : KURARAY)- and one multi-step dentin bonding system-Scotchbond$^{TM}$Multi-Purpose (SBMP, 3M Dental Products)-as control according to manufacturers' instructions. Cavities were restored with Spectrum$^{R}$(Dentsply). Specimens were immersed in saline for 24 hours and sectioned longitudinally with a low-speed diamond disc. The resin-dentin interfaces were microscopically observed using CLSM. The quality of resin-infiltrated dentin layers were evaluated by five dentists using 0~4 scale. Results : Confocal laser scanning microscopal investigations using primer labeled with rhodamine B showed that the penetration of the primer occurred along the cavity margins. Statistical analysis using one-way ANOVA followed by Duncan's Multiple Range test revealed that the primer penetration of the group 2(wedge-shaped cavity preparation) was more effective than group 1(cervical abrasion) and that of the gingival interfaces was more effective than the occlusal interfaces. In the one-bottle dentin bonding systems, the resin penetration score of OCB was compatible to SBMP, but those of SS and self-etching priming system, SB were lower than SBMP.

• Journal of Power Electronics
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• v.17 no.3
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• pp.821-834
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• 2017

This paper reports on a single-inductor multiple-output step-up converter with digital control. A systematic analog-to-digital-controller design is explained. The number of digital blocks in the feedback path of the proposed converter has been decreased. The simpler digital pulse-width modulation (DPWM) architecture is then utilized to reduce the power consumption. This architecture has several advantages because counters and a complex digital design are not required. An initially designed unit-delay cell is adopted recursively for the construction of coarse, intermediate, and fine delay blocks. A digital limiter is then designed to allow only useful code for the DPWM. The input voltage is 1.8 V, whereas output voltages are 2 V and 2.2 V. A co-simulation was also conducted utilizing PowerSim and Matlab/Simulink, whereby the 55 nm process was employed in the experimental results to evaluate the performance of the architecture.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.11
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• pp.4568-4575
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• 2010

Iris recognition is a biometric technology that uses iris pattern information, which has features of stability, security etc. Because of this reason, it is especially appropriate under certain circumstances of requiring a high security. Recently, using the iris information has a variety uses in the fields of access control and information security. In extracting the iris feature, it is desirable to extract the feature which is invariant to size, lights, rotation. We have easy solutions to the problem of iris size and lights by previous processing but there is still problem of iris feature extract invariant to rotation. In this paper, To improve an awareness ratio and decline in speed for a revision of rotation, it is proposed that the iris recognition method using Zernike Moment and Daubechies Wavelet. At first step, the proposed method groups rotated iris into similar things by statistical feature of Zernike Moment invariant to a rotation, which shortens processing time of iris recognition and looks equal to an established method in the performance of recognition too. therefore, proposed method could confirm the possibility of effective application for large scale iris recognition system.

• Journal of the Korean Society of Physical Medicine
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• v.18 no.3
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• pp.55-64
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• 2023

PURPOSE: Examine the effects of auditory feedback and functional electrical stimulation on balance, walking ability, and lower extremity function of subacute stroke patients. METHODS: Twenty-seven subjects diagnosed with subacute stroke within six months were randomly divided into three groups: test group 1, which performed walking exercises with auditory feedback and functional electrical stimulation; test group 2, which performed walking exercises only with functional electrical stimulation; control group applied only functional electrical stimulation, with nine subjects each. RESULTS: There were significant pre- to post-intervention differences in BBS in the gait training group with auditory feedback and functional electrical stimulation treatment, and significant pre- to post-intervention differences in BBS, sit-to-stand time, and average step speed in the gait training group with functional electrical stimulation, but no statistically significant differences in between-group comparisons. CONCLUSION: Gait training with auditory feedback and functional electrical stimulation can improve the balance and gait performance in stroke patients. Therefore, in the future, gait training with auditory feedback and functional electrical stimulation therapy may be suggested as a gait rehabilitation training tool for stroke patients.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.7 s.337
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• pp.35-40
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• 2005

This paper proposes a fractional-N phase-locked loop (PLL) frequency synthesizer using the 3rd order ${\Delta}{\sum}$ modulator for 900MHz medium speed wireless link. The LC voltage-controlled oscillator (VCO) is used for the good phase noise property. To reduce the lock-in time, a charge pump has been developed to control the pumping current according to the frequency steps and the reference frequency is increased up to 3MHz. A 36/37 fractional-N divider is used to increase the reference frequency of the phase frequency detector (PFD) and to reduce the minimum frequency step simultaneously. A 3rd order ${\Delta}{\sum}$ modulator has been developed to reduce the fractional spur VCO, Divider by 8 Prescaler, PFD and Charge pump have been developed with 0.25um CMOS, and the fractional-N divider and the third order ${\Delta}{\sum}$ modulator have been designed with the VHDL code, and they are implemented through the FPGA board of the Xilinx Spartan2E. The measured results show that the output power of the PLL is about -lldBm and the phase noise is -77.75dBc/Hz at 100kHz offset frequency. The minimum frequency step and the maximum lock-in time are 10kHz and around 800us for the maximum frequency change of 10MHz, respectively.

• The Journal of Korean Physical Therapy
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• v.9 no.1
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• pp.127-145
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• 1997

The purpose of this study wa9 to analyse the gait patterns of two female children with hemiplegic cerebral palsy by using the three-dimensional video motion analysis technique. Case 1 has mild spastic hemiplegia on the right side while Case 3 has moderate spastic hemiplegia on the left side. A group of 10, normal female children of the same age(7-8 years old) were selected as the control group for comparison. Time and distance variables as well as the Center of Mass displacement, and the pelvic and joint motions in three anatomical planes were analysed for this purpose. The following observations were made through the analysis : Case 1 revealed an asymmetrical gait pattern in which the step length of the unaffected side was shorter than that of the affected side, which wan a result of the effort to minimize loading on the affected leg by shortening the swing phase of the unaffected leg. Case 1 scored similar phase ratios, cadence and walking velocity to the normal group. A slight posterior tilt of the pelvis was observed throughout the gait cycle. Less hip and knee flexion than the normal group was observed, and demonstrated hyperextension of the knee in the terminal stance phase. The main problem in case 1 originated from the insufficient dorsiflexion of the affected foot during the swing phase. Therefore, Case 1 has difficulty with foot clearance in the swing phase. Usually, this is compensated for by using exessive hip abduction and medial rotation in conjuction with trunk elevation as well as increased vortical displacement of the center of mass. Case 1 revealed a foot-flat initial contact pattern. Case 2 was characterized by a consistent retraction ef the affected aide of the body througout the gait cycle, As a result, an asymmetrical gait pattern with increased stance phase ratios of the unaffected side was observed. In spite of this the step lengths of both sieds were similar. Case 2 scored lower cadence and walking speed than the normal group with lower gait stability. The main problem in Case 2 originated from an excessive plantaflexion of the affected foot which, in turn, rebutted in high hip and knee flexion. Hyperextension of the knee was observed at mid-stance, and execessive anterior tilt of the pelvis throughout the gait cycle was noticed. A gait pattern with high hip abduction and medial circumduction was maintained for the stability in the stance phase and foot clearance in the swing phase. Case 2 revealed a forefoot-contact initial contact pattern.