• Journal of Korean Ophthalmic Optics Society
• /
• v.16 no.1
• /
• pp.51-60
• /
• 2011

Purpose: This study was to investigate visual performance and subjective satisfaction with multifocal soft contact lenses at near works in university students. Methods: In a cross-over study design, 26 students (6 male, 20 female) who did not have any ocular disorder with at least 20/20(1.0) binocular vision were fitted with singlevision lenses (SofLens$^{TM}59$, Bausch + Lomb Co. USA) or multifocal lenses (SofLens Multifocal, Bausch + Lomb Co. USA). After 2 weeks, visual performance assessments included visual acuity, stereoacuity and contrast sensitivity function at distance and near. Near point of accommodation, accommodative facility, near point of convergence, vergence facility and near range of clear vision at near were examined. Students' satisfaction and preference were measured using survey questionaries. Results: Subjects maintained at least 20/20 binocular vision with multifocal and single-vision lenses at distance and near. There was no difference between multifocal and single-vision lenses in stereoacuity, contrast sensitivity function and vergence facility at far and near. The near point of accommodation, accommodative facility, near point of convergence and the near range of clear vision with multifocal lenses were better than single-vision lenses. On the survey questionaries, subjects reported that they preferred and satisfied with multifocal lenses with near works, and single-vision lenses with distance works. Conclusions: The majority of university students preferred multifocal to single vision lenses because multifocal lenses provided better visual performance at near works. This study suggests that multifocal lens is helpful for young adult in prolonged near works.

• Archives of Reconstructive Microsurgery
• /
• v.21 no.2
• /
• pp.131-136
• /
• 2012

Purpose: Arterialized venous flap is useful for reconstruction of the traumatic soft tissue defect in fingers, but insufficient circulation of the traumatic fingers makes surgeons annoying to use the flap. We have grafted flaps in 7 fingers with insufficient vascular bed hoping to expanded the category of the flap. Materials and Methods: Arterialized venous flap have transplanted in 7 fingers from March 2008 through February 2010 and followed up for 4 to 16 months(average 7.2 months). They were all male with a mean age at the time of surgery was 33. The main injury was crushing in 4 degloving, contact burn and saw injury was I respectively. Time interval from injury to flap transplantation was average 3.1. weeks(3 days to 6 weeks). Designed flap size ranges from $8cm{\times}3.5cm$to $4cm{\times}3cm$. Vessel type of flap was one artery with two veins were 5 cases and one artey with one vein 2. Flap type was cutaneous in 3, tendocutaneous 2, neurotendocutaneous 1 and neurocutaneous 1. The circulation state of recipient site was avascular in 2 cases, insufficiency 3 and tip avascular 2. Results: Arterialized venous flap was complete survived in 2 cases, partial necrosis(less than 10%) 3 and failed in 2. Conclusion: An arterialized venous free flap could be a useful procedure for reconstruction in soft tissue or combined defect of the finger despite an avascular or insufficient vascular beds if the recipient beds were free from infection.

• The Plant Pathology Journal
• /
• v.17 no.5
• /
• pp.257-263
• /
• 2001

Species of the genus Orobanche are parasitic flowering plants, holoparasites, which cling to the roots of green plants. Their tiny seeds (200 x $250\mu\textrm{m}$) germinate in response to chemical stimuli produced by host and some non-host plants. Successful contact with their host leads to development of haustoria for obtaining water and food. The shoots above the ground expose flowers and disseminate seeds. Several samples of Orobanche ramosa, O. crenata, O. cernua, and O. egyptiaca were collected from different localities in Jordan. These samples showed one of the following disease symptoms: dry rot at the base of the stem; general deterioration and expanded lesion from base upward; soft tissue maceration of stem; and black rot of flower parts with incomplete maturation of the ovary and seeds. Isolation from diseased stems and seeds was made on three different mycological media. Several fungi were isolated, mainly, Fusarium spp., Alternaria alternata, Rhizoctonia sp., Dendrophora sp., Chaetomium sp., and an ascomycetus fungus with a perithecium. Pathogenicity tests showed that Fusarium spp. and Alternaria alternata attacked healthy living tissue of Orobanche spikes. These fungi caused lesions of black soft rot and complete deterioration within 5-7 days. They also attacked Orobanche seeds, arresting their germination and causing maceration of non-germinated and germinated seeds after 5-7 days of incubation. Meanwhile, Dendrophora sp. and Chaetomium sp. caused limited lesion at first, but were able to colonize the tissue as it aged and senesced. This study showed the presence of a potential endogenous pathogenic fungi in Jordan, which can be investigated as a biological control for Orobanche.

• Journal of information and communication convergence engineering
• /
• v.8 no.1
• /
• pp.1-5
• /
• 2010

In this paper, we propose for improving QoS in wireless micro cellular network using Cellular-IP/PRC(Paging Route Cache) with Paging Cache and Route Cache in Cellular-IP and propose for performance of realtime and non-real time handoff service using Handoff state machine Paging Route Cache. Although the Cellular-IP/PRC technology is devised for mobile internet communication, it bas its vulnerability in frequent handoff environment. On the other hand, Cellular IP combines the capability of cellular networks to provide high performance handoff and efficient location management of active and idle mobile users with the inherent flexibility, robustness and scalability found in IP networks. Also Cellular-IP/PRC use semi-soft handoff. During semi-soft hand off a mobile host may be in contact with either of the old and new base stations and receive packets from them. Packets intended to the mobile node are sent to both base stations and buffered, so when the mobile host eventually moves to the new location it can continue to receive packets without interruption. It should be suitable for realtime service such as multimedia traffic. But, much waste of resource will occur in this method, especially for non-real time services such as FTP and E-mail. Therefore, a new algorithm that performs different handoff according to characteristic of each traffic by use of reserved field in IP packet is proposed in this thesis. This hand off state machine using differentiated handoff improves quality of services in Cellular-IP/PRC. Suggested algorithm shows better performance than existing technology in wireless mobile internet communication environment. Matlab simulation results are improving QoS, show call drop and call blocking provided to Paging Router Cache during handoff state machine in Cellular-IP/PRC.

• Journal of the Microelectronics and Packaging Society
• /
• v.27 no.3
• /
• pp.83-88
• /
• 2020

The evolution of smartphones has led to numerous researches in the mechanical behavior of flexible devices. Due to the nano-size of the thin flexible film, nanoindentation is widely used to evaluate its mechanical behaviors, such as elastic modulus, and hardness. However, the commonly used Oliver-Pharr method is not suited for analyzing the indentation force-depth curves of hard films on soft substrates, as the effects of soft substrate is not considered theoretically. In this study, the elastic modulus of the thin film was evaluated with references to other reported models which include the substrate effect, and with calibration of the indentation depth for the pile-ups between the indenter and test surface. We fabricated test samples by deposition of amorphous metal film on polyimide and silicon wafers for verification of modified models.

• Journal of the Korean Geosynthetics Society
• /
• v.11 no.1
• /
• pp.57-63
• /
• 2012

Steel slag has the nature to hydrate and expand when in contact with non-reacting CaO and water, and thus can be used only in limited scope for landfill disposal as well as for recycling as civil construction aggregates. In order to use such steel slags more efficiently, the applicability of steel slag as sand mat alternative material was reviewed. In general, sand mat is used in soft ground surface reinforcement method and horizontal drain method, and is installed simultaneously with soft ground vertical drain method. Therefore in this study steel slag designing method and application standard etc were examined to recycle steel slag as sand mat alternative material, and laboratory soil test and model test were done. Test results indicated that the designing method and application standard meet various environment and quality standards, meaning that steel slag can be utilized as sand mat alternative material, and analysis of slag mat bearing capacity also indicated that use of steel slag produces double or more bearing capacity compared with existing sand mat.

• Journal of Periodontal and Implant Science
• /
• v.26 no.2
• /
• pp.522-530
• /
• 1996

Most dentists are very interested in laser therapy on the intraoral soft tissue lesions because they want to accomplish the analgesic and aseptic surgery with little or no bleeding. In order to determine the difference of pain threshold according to different gingival tissues with or without inflammation, 25 patients with inflammatory periodontal disease and 10 volunteers with good general and oral health were selected as the inflamed group and the normal group, respectively. Interdental papilla, marginal gingiva, attached gingiva, and alveolar mucosa were irradiated by the contact delivery($300{\mu]m$ fiber optic, for 5 seconds) of a pulsed Nd:YAG laser(EN.EL.EN06O, Italy). And the laser power was gradually increased from 0.5W by the increment of 0.1W. The highest laser power was recorded as the first painful power when the painful gesture was recognized at first. The difference of the first painful power of laser according to different gingival tissues with or without inflammation was statistically analyzed by paired t-test in MICROSTAT program. Following results were obtained: 1. In the comparison related with the inflammation, the first painful power was significantly lower in the inflamed group than in the normal group, regardless of interdental papilla and marginal gingiva(p<0.05). 2. In the comparison related with the tissue structure, the first painful. power was significantly lower in alveolar mucosa than in attached gingiva(p<0.05). The results suggest that, for the painless therapy by a pulsed-Nd:YAG laser irradiation, the laser surgery over 2.0W of power should be necessarily accomplished under the local anethesia, and the local anesthesia should be considered according to the degree of inflammation, the tissue structure, and the purpose of laser therapy.

• Journal of the Optical Society of Korea
• /
• v.12 no.4
• /
• pp.309-313
• /
• 2008

We studied the sapphire and germanium fibers to determine which optical fiber best transmits Erbium:YAG laser for intracorporeal lithotripsy. Human calculi were ablated with an Erbium:YAG laser in contact mode using two fibers. Optical outputs at the distal end of fibers were measured before and after laser lithotripsy. Upon the irradiation on the calculus with the 50 mJ and 100 mJ pulse energy, the output energy at the distal end of germanium fiber declined to approximately 50% of the input energy. For the sapphire fiber, the output energy at the distal end remained unchanged with 100 mJ input energy; however the output energy had dropped to 50% for 200 mJ input energy. In order to examine how the types of target tissue affect the fiber damage, the sapphire fiber was tested for the irradiation on soft tissue and water as well. No energy decline was observed during soft tissue and water irradiation. We also characterized ablation craters with both optical fibers. Both fibers produced similar craters on calculi in terms of depth and diameter. Sapphire fibers are better suited than germanium fibers for Erbium:YAG lithotripsy in terms of the fiber damage.

• Advances in nano research
• /
• v.10 no.3
• /
• pp.253-261
• /
• 2021

Polydimethylsiloxane (PDMS) is one of the most widely adopted silicon-based organic polymeric elastomers. Elastomeric nanostructures are normally required to accomplish an explicit mechanical role and correspondingly their mechanical properties are crucial to affect device and material performance. Despite its wide application, the mechanical properties of PDMS are yet fully understood. In particular, the time dependent mechanical response of PDMS has not been fully elucidated. Here, utilizing state-of-the-art PeakForce Quantitative Nanomechanical Mapping (PFQNM) together with Force Volume (FV) and Fast Force Volume (FFV), the elastic moduli of PDMS samples were assessed in a time-dependent fashion. Specifically, the acquisition frequency was discretely changed four orders of magnitude from 0.1 Hz up to 2 kHz. Careful calibrations were done. Force data were fitted with a linearized DMT contact mechanics model considering surface adhesion force. Increased Young's modulus was discovered with increasing acquisition frequency. It was measured 878 ± 274 kPa at 0.1 Hz and increased to 4586 ± 758 kPa at 2 kHz. The robust local probing of mechanical measurement as well as unprecedented high-resolution topography imaging open new avenues for quantitative nanomechanical mapping of soft polymers, and can be extended to soft biological systems.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.28 no.3A
• /
• pp.323-330
• /
• 2008

The ship collision analysis of steel pile group as protection system of bridge in navigable waterways was performed to analyze the structural characteristics of protective structure during ship collision. The analysis encompassed finite element modeling of ship and pile, modeling of material non-linearity, hard impact analysis, displacement-based analysis and soft impact analysis for collision scenarios. Through the analysis of hard impact with a rigid wall, impact load for each collision type of ship bow was estimated. In the displacement-based analysis the estimate of energy which protection system can absorb within its maximum horizontal clearance so as to secure bridge pier from vessel contact during collision was performed. Soft impact analysis for various collision scenarios was conducted and the collision behaviors of vessel and pile-supported protection system were reviewed for the design of protection system. The understanding of the energy dissipation mechanism of pile supported structure and colliding vessel would give us the optimized design of protective structure.