• The KIPS Transactions:PartD
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• v.16D no.1
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• pp.93-104
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• 2009

Modular implementation of a feature is a first step toward feature-oriented product line engineering, which develops and then utilizes core assets to configure products in terms of features. Aspect-oriented programming provides effective mechanisms for improving the modularity of feature implementations. However, as features in general are not independent of each other, changes in the implementation of one feature may cause changes to or side effects in the implementation of other features. Moreover, since the time at which a feature is incorporated into products, called feature binding time, may be various from compile time through load time to run time, a feature may have to be implemented differently depending on when the feature is bound into a product. To make each feature implementation module as independent as possible, this paper proposes aspectual implementation patterns that can effectively separate feature dependencies as well as feature binding time from feature implementation modules. These patterns enable flexible composition of feature implementation modules without affecting other modules according to feature selection. The approaches are demonstrated and evaluated based on a product line of scientific calculator applications.

• Bulletin of the Korean Chemical Society
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• v.12 no.5
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• pp.554-559
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• 1991

The photophysical and photochemical properties of khellin were compared with those of 8-methoxypsoralen (8-MOP). Quantum yields of fluorescence and triplet formation decreases as solvent polarity increases, which is opposite to 8-MOP, and photocycloadditivity of khellin to olefins is much lower than that of 8-MOP. Electron ejection from khellin by laser flash was not observed, but observed from 8-MOP. As models of 4',5'-monoadducts of khellin or 8-MOP with thymine base, khellin<>dimethylfumarate 4',5'-monoadduct (KDF) was also compared with 8-MOP<>thymidine 4',5'-monoadduct (F-2) in those properties to give some insight on the second-step biadduct formation resulting in cross-links of DNA duplex. KDF and F-2 were very similar to khellin and 8-MOP in photophysical properties, respectively. However, KDF did not form adducts with various olefins, and thus it is thought that 2,3-double bond of chromone moiety in khellin is hardly reactive in contrast with 3,4-double bond of coumarin moiety in 8-MOP. These results indicate that khellin is fairly photostable compound, a poor type Ⅰ photodynamic sensitizer and producer of ${O_2}^{-}$ which is some cause of phototoxic erythemal reactions and undesirable side effects. Therefore khellin is safer to use than 8-MOP in photochemotherapy of some skin diseases. Although khellin is much less reactive than 8-MOP, khellin must be also a monofunctional drug. Since khellin is, however, as effective as 8-MOP in photochemotherapy of some skin diseases, it is suggested that khellin may be different from 8-MOP in the action mechanism.

• Bulletin of the Korean Chemical Society
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• v.19 no.6
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• pp.671-676
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• 1998

The formation and dissociation rates of $Ce^{3+}$ Complexes of the 1,4,7,10-tetraaza-13,16-dioxacyclooctadecane-NN', N",N"'-tetraacetic acid (1), 1,4,7,10-tetraaza-13,16-dioxacyclooctadecane-N,N',N",N"'-tetramethylacetic acid (2), and 1,4,7,10-tetraaza-13,16-dioxacyclooctadecane-N,N',N",N"'-tetrapropionic acid (3) have been measured by the use of stopped-flow spectrophotometry. Observations were made at 25.0±0.1 ℃ and at an ionic strength of 0.10 M $NaClO_4$. The complexation of $Ce^{3+}$ ion with 1 and 2 proceeds through the formation of an intermediate complex $(CeH_3L^{2+})^*$ in which the $Ce^{3+}$ ion is incompletely coordinated. This may then lead to be a final product in the rate-determining step. Between pH 4.76 and 5.76, the diprotonated $(H_2L^{2-})$ from is revealed to be a kinetically active species despite of its low concentration. The stability constants $(logK(CeH_3L^{2+}))$ and specific water-assisted rate constants $(k_{OH})$ of intermediate complexes have been determined from the kinetic data. The dissociation reactions of $Ce^{3+}$ complexes of 1, 2, and 3 were investigated with $Cu^{2+}$, ions as a scavenger in acetate buffer. All complexes exhibit acid-independent and acid-catalyzed contributions. The effect of buffer and $Cu^{2+}$ concentration on the dissociation rate has also been investigated. The ligand effect on the dissociation rate of $Ce^{3+}$ complexes is discussed in terms of the side-pendant arms and the chelate ring sizes of the ligands.

• Journal of Power Electronics
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• v.19 no.4
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• pp.881-893
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• 2019

This paper proposes a practical sliding-mode controller design for shaping the impedances of cascaded boost-converter power decoupling circuits for reducing the second order harmonic ripple in photovoltaic (PV) current. The cascaded double-boost converter, when used as power decoupling circuit, has some advantages in terms of a high step-up voltage-ratio, a small number of switches and a better efficiency when compared to conventional topologies. From these features, it can be seen that this topology is suitable for residential (PV) rooftop systems. However, a robust controller design capable of rejecting double frequency inverter ripple from passing to the (PV) source is a challenge. The design constraints are related to the principle of the impedance-shaping technique to maximize the output impedance of the input-side boost converter, to block the double frequency PV current ripple component, and to prevent it from passing to the source without degrading the system dynamic responses. The design has a small recovery time in the presence of transients with a low overshoot or undershoot. Moreover, the proposed controller ensures that the ripple component swings freely within a voltage-gap between the (PV) and the DC-link voltages by the small capacitance of the auxiliary DC-link for electrolytic-capacitor elimination. The second boost controls the main DC-link voltage tightly within a satisfactory ripple range. The inverter controller performs maximum power point tracking (MPPT) for the input voltage source using ripple correlation control (RCC). The robustness of the proposed control was verified by varying system parameters under different load conditions. Finally, the proposed controller was verified by simulation and experimental results.

• Journal of the Korean Applied Science and Technology
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• v.39 no.4
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• pp.527-534
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• 2022

The purpose of this study was to investigate the effects of 12 weeks of muscle power and agility training on physical fitness factors and isokinetic muscle function in elementary school male soccer players. For this purpose, 6 muscle power and agility training programs were organized for 12 elementary school male soccer players and were conducted 3 times a week for 12 weeks. The results of measurement and analysis of physical fitness factors before and after the muscle strength and agility training are as follows. First, there was a significant difference in the standing long jump in place of muscle power(p<.001). Second, there was a significant difference in the standing vertical jump of muscle power(p<.05). Third, there was a significant difference in the side step of agility(p<.01). As a result, 12 weeks of muscle power and agility training can be expected to have a positive effect on the improvement of agility and agility of elementary school male soccer players, and it is judged that it can provide training basic data for injury prevention and performance improvement.

• Journal of Aerospace System Engineering
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• v.16 no.5
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• pp.86-93
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• 2022

Generally, a deployable solar panel is used primarily to achieve sufficient power output to perform the mission. However, temperature distribution on the antenna reflector may increase due to the shading effect induced by the presence of the deployable solar panels. Appropriate thermal design is critical to minimize the thermal deformation of the mesh antenna reflector in harsh on-orbit thermal environments to ensure remote frequency (RF) performance. In this paper, we proposed a dual-surface primary reflector consisting of a mesh antenna and a flexible fabric membrane sheet. This design strategy can contribute to thermal stabilization by using a flexible solar panel on the rear side of membrane sheet to reduce the temperature distribution caused by the deployable solar panel. The effectiveness of the mesh antenna design strategy investigates through on-orbit thermal analysis.

• Physical Therapy Korea
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• v.30 no.2
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• pp.110-119
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• 2023

Background: Osteoarthritis is a common condition with an increasing prevalence and is a common cause of disability. Osteoarthritic pain decreases the quality of life, and simple gait training is used to alleviate it. Knee osteoarthritis limits joint motion in the sagittal and lateral directions. Although many recent studies have activated orthotic research to increase knee joint stabilization, no study has used patellar tendon straps to treat knee osteoarthritis. Objects: This study aimed to determine the effects of patellar tendon straps on kinematic, mechanical, and electromyographic activation in patients with knee osteoarthritis. Methods: Patients with knee osteoarthritis were selected. After creating the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC), leg length difference, Q-angle, and thumb side flexion angle of the foot were measured. Kinematic, kinetic, and muscle activation data during walking before and after wearing the orthosis were viewed. Results: After wearing the patellar tendon straps, hip adduction from the terminal stance phase, knee flexion from the terminal swing phase, and ankle plantar flexion angle increased during the pre-swing and initial swing phases. The cadence of spatiotemporal parameters and velocity increased, and step time, stride time, and foot force duration decreased. Conclusion: Based on the results of this study, the increase in plantar flexion after strap wearing is inferred by an increase due to neurological mechanisms, and adduction at the hip joint is inferred by an increase in adduction due to increased velocity. The increase in cadence and velocity and the decrease in gait speed and foot pressure duration may be due to joint stabilization. It can be inferred that joint stabilization is increased by wearing knee straps. Thus, wearing a patellar tendon strap during gait in patients with knee osteoarthritis influences kinematic changes in the sagittal plane of the joint.

• Journal of Digestive Cancer Research
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• v.5 no.1
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• pp.23-27
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• 2017

Although laparoscopic pancreaticoduodenectomy (LPD) is considered as minimally invasive surgery, an advanced level of laparoscopic skill is still required. LPD comprises various procedures including reconstruction. Therefore, establishment of a safe approach at each step is needed. Prevention of intraoperative bleeding is the most important factor in safe completion of LPD. The establishment of effective retraction methods is also important at each site to prevent vascular injury. I also recommend the "uncinate process first" approach during initial cases of LPD, in which the branches of the inferior pancreaticoduodenal artery are dissected first, at points where they enter the uncinate process. This approach is performed at the left side of the superior mesenteric artery (SMA) before isolating the pancreatic head from the right aspect of the SMA, which allows safe dissection without bleeding. Safe and reliable reconstruction is also important to prevent postoperative complications. Laparoscopic pancreatojejunostomy requires highly skilled suturing technique. Pancreatojejunostomy through a small abdominal incision, as in hybrid-LPD, facilitates reconstruction. In LPD, the surgical view is limited. Therefore, we must carefully verify the position of the pancreaticobiliary limb. A twisted mesentery may cause severe congestion of the pancreaticobiliary limb following reconstruction, resulting in severe complications. We must secure the appropriate position of the pancreaticobiliary limb before starting reconstruction. We describe the incidence of intraoperative and postoperative complications and appropriate technique for safe performance of LPD.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.4 no.2
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• pp.267-282
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• 1997

This study was to test the relationship between regular physical exercise and physical fitness in nursing students. These subjects were 54 volunteers who agreed with intention of this study and were composed of 24 active group and 30 non-active group. The selected physical fitness tests were grip strength and back strength for measuring muscular strength, sargent jump and standing broad jump for measuring power, push-up, sit-up, and heart rate for measuring total endurance, reaction time and side step test for measuring agility, stick test and stork stand for measuring balance, and trunk flexion and trunk extension for measuring flexibility. The conclusion acquired was as follows : 1) Grip strength had significant difference between active group of $29.5{\pm}5.9kg$ and non-active group $25.4{\pm}7.2kg$(t=2.283, p=.027), and back strength between active group of $54.1{\pm}13.7kg$ and non-active group of $44.7{\pm}15.7kg$(t=2.310, p=.025), 2) Sargent jump was lower with non-active group($44.9{\pm}8.6cm$) than with active group($45.3{\pm}8.8cm$), however, was not significant(t=.182, p=.856). Standing broad jump was significantly lower with non-active group of $161.3{\pm}28.7cm$ than with active group of $191.4{\pm}27.0cm$(t=3.939, p=.000). 3) Push-up showed significant difference between active group of $25.3{\pm}12.3times$ and non-active group of $11.5{\pm}5.1times$(t=5.572, p=.000), and sit-up between active group of $21.8{\pm}7.4times$ and non-active group of $17.1{\pm}5.8times$(t=2.631, p=.011), and heart rate between actvie group of $110.5{\pm}12.8$beats/min and non-active group of $121.5{\pm}9.5$beats/min(t=-3.648, p=.001). 4) Reaction time was significantly higher with non-active group of $.300{\pm}.051sec$ than with active group of $.341{\pm}.041sec$(t=-3.285, p=.002). Side step test was lower with non-active group($8.8{\pm}1.1times$) than with active group($9.2{\pm}1.2times$), however, was not significant (t=1.309, p=.196). 5) Stick test showed not significant difference between active group of $25.8{\pm}14.8sec$ and non-active group of $30.7{\pm}17.9sec$(t=-1.058, p=.295), and stork stand between active group of $4.5{\pm}3.2sec$ and non-active group of $3.7{\pm}3.5sec$(t=.918, p=.363). 6) Trunk flexion came out not significant difference between active group of $14.2{\pm}5.0cm$ and non-active group of $15.8{\pm}7.3cm$(t=-.927, p=.358), and trunk extension between active group of $67.1{\pm}6.5cm$ and non-active group of $67.3{\pm}6.6cm$(t=-.140, p=.889). 7) Power was shown to be significantly related to total endurance(r=.717, p=.000 ; r-.739, p=.000). 8) Total endurance was shown to be significantly related to agility(r=-.752, p=.000 ; r=.684, p=.000 ; r=-.664, p=.000 ; r=.598, p=.002 ; r=.864, p=.000 ; r=-.536, p=.007). These results suggest that regular physical exercise is effective in promoting and maintaining physical fitness. As the further study, it is necessary to reinvestigate the effect with more refined design.

• The Journal of Korean Academy of Prosthodontics
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• v.52 no.2
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• pp.97-104
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• 2014

This study was aimed to compare the radiopacity of four kinds of currently available resin based implant cements using digital radiography. Materials and Methods: Four resin-based implant cements((Estemp $Implant^{TM}$ (Spident, Incheon, Korea), $Premier^{(R)}$Implant (Premier, Pennsylvania, USA), $Cem-Implant^{TM}$ (B.J.M lab, Or-yehuda, Israel), $InterCem^{TM}$ (SCI-PHARM, California, USA)) and control group (Elite Cement $100^{TM}$ (GC, Tokyo, Japan) ) were mixed and cured according to the manufacturer's instructions on the custom made split-type metal mold. A total of 150 specimens of each cement were prepared and each specimen (purity over 99%) was placed side-by-side with an aluminum step wedge for image taking with Intraoral X-ray unit (Esx, Vatech, Korea) and digital X-ray sensor (EzSensor, Vatech, Korea). For the evaluation of aluminum wedge equivalent thickness (mm Al), ImageJ 1.47 m (Wayne Rasband, National Institutes of Health, USA) and Color inspector 3D ver 2.0 (Interaktive Visualisierung von Farbraumen, Berlin, Germany) programs were used. Result: Among the 5 cements, Elite cement $100^{TM}$ (control group) showed the highest radio-opacity in all thickness. In the experimental group, $InterCem^{TM}$ had the highest radio-opacity followed by $Premier^{(R)}$ Implant $Cement^{TM}$, $Cem-Implant^{TM}$ and Estemp $Implant^{TM}$. In addition, $InterCem^{TM}$ showed radio-opacity that met the ISO No. 4049 standard in all the tested specimen thickness. Cem-Implant on 0.5 mm thickness showed radiopacity that met the ISO No. 4049 standard. Conclusion: Among the implant resin-based cements tested in the study, $Premier^{(R)}$ Implant Cement and Estemp $Implant^{TM}$ did not show appropriate radio-opacity. Only $InterCem^{TM}$ and $Cem-Implant^{TM}$ 0.5 mm specimen had the proper radiopacity and met the experiment standard.