• Journal of Acupuncture Research
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• v.26 no.3
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• pp.133-147
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• 2009

Objectives : To review RCTs on acupuncture treatment for low back pain in order to establish a standard acupuncture treatment model in treating low back pain. Methods : RCT articles on traditional acupuncture treatment for low back pain were searched through online database. Study Quality was assessed using the FEAS. Results : Ten out of the one hundred six articles searched were reviewed. Among the ten articles reviewed, six articles compared acupuncture treatment with no treatment or non-penetrating sham acupuncture. All six articles concluded significantly positive effect of acupuncture compared to the control. Conclusions : The ideal acupuncture treatment model for low back pain was obtained as follows. A sterile disposable stainless steel(0.30mm${\times}$40mm) should be inserted to more than six acupuncture points on the BL, GV and GB meridians such as $BL_23$, $BL_25$, $BL_40$, $BL_60$, $GV_4$ and $GB_30$. Sparrow pecking method to obtain 'de-qi' is recommended and repeated stimulation during the 20 minute retention time is necessary. Ideal treatment frequency would be more than one a week for about 7 weeks.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.37
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• pp.34.1-34.14
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• 2015

Background: Over the past 30-40 years, various carbon implant materials have become more interesting, because they are well accepted by the biological environment. The traditional carbon-based polymers give rise to many complications. The polymer complication may be eliminated through carbon fibres bound by pyrocarbon (carbon/carbon). The aim of this study is to present the long-term clinical results of carbon/carbon implants, and the results of the scanning electron microscope and energy dispersive spectrometer investigation of an implant retrieved from the human body after 8 years. Methods: Mandibular reconstruction (8-10 years ago) was performed with pure (99.99 %) carbon implants in 16 patients (10 malignant tumours, 4 large cystic lesions and 2 augmentative processes). The long-term effect of the human body on the carbon/carbon implant was investigated by comparing the structure, the surface morphology and the composition of an implant retrieved after 8 years to a sterilized, but not implanted one. Results: Of the 16 patients, the implants had to be removed earlier in 5 patients because of the defect that arose on the oral mucosa above the carbon plates. During the long-term follow-up, plate fracture, loosening of the screws, infection or inflammations around the carbon/carbon implants were not observed. The thickness of the carbon fibres constituting the implants did not change during the 8-year period, the surface of the implant retrieved was covered with a thin surface layer not present on the unimplanted implant. The composition of this layer is identical to the composition of the underlying carbon fibres. Residual soft tissue penetrating the bulk material between the carbon fibre bunches was found on the retrieved implant indicating the importance of the surface morphology in tissue growth and adhering implants. Conclusions: The surface morphology and the structure were not changed after 8 years. The two main components of the implant retrieved from the human body are still carbon and oxygen, but the amount of oxygen is 3-4 times higher than on the surface of the reference implant, which can be attributed to the oxidative effect of the human body, consequently in the integration and biocompatibility of the implant. The clinical conclusion is that if the soft part cover is appropriate, the carbon implants are cosmetically and functionally more suitable than titanium plates.

• Journal of the Korean Vacuum Society
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• v.17 no.1
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• pp.9-15
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• 2008

Various diatomic inorganic films and their composite films are packed as passivation films covering Ca cells on glass substrates by using an electron-beam evaporation technique. When these Ca cells are exposed to an ambient atmosphere, the water vapor penetrating through the passivation layers is absorbed in the Ca cells, resulting in a gradual progress of transparency in the Ca cells, which can be represented by changes of the optical transmittance in the visible range. Compared with the saturation times for the Ca cells to become completely transparent in the atmosphere, the protection effects of water vapor are estimated for various passivation films. The composite films consisting silicon oxide($SiO_2$) and tin oxide($SnO_2$) or zinc oxide(ZnO) are found to show a superior protection effect of water vapor as compared with diatomic inorganic films. Also, the main factors affecting the permeation of water vapor through the oxide films are found to be the polarizability and the packing density.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.296-296
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• 2014

We investigate experimentally and theoretically the splitting of surface plasmon (SP) resonance peaks under TE- and TM-polarized illumination. The SP structure at infrared wavelength is fabricated with a 2-dimensional square periodic array of circular holes penetrating through Au (gold) film. In brief, the processing steps to fabricate the SP structure are as follows. (i) A standard optical lithography was performed to produce to a periodic array of photoresist (PR) circular cylinders. (ii) After the PR pattern, e-beam evaporation was used to deposit a 50-nm thick layer of Au. (iii) A lift-off processing with acetone to remove the PR layer, leading to final structure (pitch, $p=2.2{\mu}m$; aperture size, $d=1.1{\mu}m$) as shown in Fig. 1(a). The transmission is measured using a Nicolet Fourier-transform infrared spectroscopy (FTIR) at the incident angle from $0^{\circ}$ to $36^{\circ}$ with a step of $4^{\circ}$ both in TE and TM polarization. Measured first and second order SP resonances at interface between Au and GaAs exhibit the splitting into two branches under TM-polarized light as shown in Fig. 1(b). However, as the incidence angle under TE polarization is increased, the $1^{st}$ order SP resonance peak blue-shifts slightly while the splitting of $2^{nd}$ order SP resonance peak tends to be larger (not shown here). For the purpose of understanding our experimental results qualitatively, SP resonance peak wavelengths can be calculated from momentum matching condition (black circle depicted in Fig. 2(b)), $k_{sp}=k_{\parallel}{\pm}iG_x{\pm}jG_y$, where $k_{sp}$ is the SP wavevector, $k_{\parallel}$ is the in-plane component of incident light wavevector, i and j are SP coupling order, and G is the grating momentum wavevector. Moreover, for better understanding we performed 3D full field electromagnetic simulations of SP structure using a finite integration technique (CST Microwave Studio). Fig. 1(b) shows an excellent agreement between the experimental, calculated and CST-simulated splitting of SP resonance peaks with various incidence angles under TM-polarized illumination (TE results are not shown here). The simulated z-component electric field (Ez) distribution at incident angle, $4^{\circ}$ and $16^{\circ}$ under TM polarization and at the corresponding SP resonance wavelength is shown in Fig. 1(c). The analysis and comparison of theoretical results with experiment indicates a good agreement of the splitting behavior of the surface plasmon resonance modes at oblique incidence both in TE and TM polarization.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.6
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• pp.2760-2766
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• 2013

Introduction : The projection method to check existence and nonexistence of radius groove penetration of screw after distal radius fracture operation clinical using the T-type plate and the radiation of radial groove tangential is to propose a new test. Material and Methods : On the tangential projection view of radius groove, elevation angle of distal radius is 2.5, 5, 7.5, 10 degree. and forearm and radiation detector of angle is 60, 70, 80, degree each changed. that analyzed check existence and nonexistence of radius groove penetration of screw. Results : For the image of Radial groove tangential. the case of not radius groove penetration of screw(63.95%, n=55), medial penetration of radius groove(10.47%, n=9) or lateral penetration of radius groove(25.58%, n=22) was analysis. The radius groove penetrating of screw length was a range of 0.43 ~ 2.72mm, the average was 1.06mm. the check existence and nonexistence of radius groove penetration of medial or lateral was analysis that it accurate for the image of Radial groove tangential. the radiography of radial groove is well described elevation angle of distal radius 2.5 to 7.5 degree(90% over), forearm and radiation detector of angle 70degree(80%over) Conclusion : It is elevation angle of distal radius is 5degree, forearm and radiation detector of angle 70degree recommended.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.12
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• pp.715-722
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• 2019

The durability of concrete structures deteriorates due to the corrosion of rebars and concrete deterioration by harmful ions (CO₃^2-, Cl^-, SO₄^2-) penetrating and diffusing from the outside into concrete. Therefore, the use of surface-protection finishing mortar is very important for preventing or delaying the deterioration of concrete. In this study, the possibility of the prevention of deterioration or delay of deterioration of concrete was investigated using natural latex modified with silica sol and calcium ions for cement mortar, which can be used to repair the mortar of deteriorated concrete or for finishing the mortar of concrete. As a result, fine calcium silicate hydrate was formed in the pores of the cement material due to the calcium ions and silica sol components contained in the modified latex component that reduce the pore distribution of the cement mortar, thereby reducing the penetration and diffusion of harmful ions (CO₃^2-, Cl^-, and SO₄^2-). Furthermore, the latex component was found to be present in the pores of the cement to improve the alkali resistance and carbonation resistance.

• Journal of Korean Society of Forest Science
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• v.94 no.1 s.158
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• pp.16-20
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• 2005

Tricholoma matsutake ectomycorrhizas are unique in their morphology: not bifurcated broom shaped roots with not easily wettable brilliant and profuse white hyphae. To understand these characteristics the ectomycorrhizas were investigated with electron microscopy. T. matsutake ectomycorrhiza have thin mantle and typical Hartig net development in the epidermis and cortex, but no fungal mantle on the root apex. There were no penetrating hyphae inside of the cells of either epidermis, cortex or stele. Inside of the walls of epidermis and cortex cells are lined with ca. $2{\mu}m$ hemispherical amyloplasts. The brilliant hyphal surface was covered with various fine amorphous granules. The hyphal cell wall was thin membrane less than $0.3{\mu}m$ thick. There is no clamp connection on the hyphae. This thin membraneous cell wall with high elasticity can be related to survival strategy of the species without plasmolysis under frequent soil water stress environment. And the coarse hyphal surface with some water repellency can control sudden inrush of water of the hyphae with an extremely low osmotic potential. It is concluded that no mantle on the tip can induce mycorrhizas not bifurcated and that finely coarse surface of T. matsutake hyphae can make the hyphae brilliantly white but less wetted.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2002.07a
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• pp.25-37
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• 2002

The most important industrial application of gamma radiation in characterizing green compacts is the determination of the density. Examples are given where this method is applied in manufacturing technical components in powder metallurgy. The requirements imposed by modern quality management systems and operation by the workforce in industrial production are described. The accuracy of measurement achieved with this method is demonstrated and a comparison is given with other test methods to measure the density. The advantages and limitations of gamma ray densitometry are outlined. The gamma ray densitometer measures the attenuation of gamma radiation penetrating the test parts (Fig. 1). As the capability of compacts to absorb this type of radiation depends on their density, the attenuation of gamma radiation can serve as a measure of the density. The volume of the part being tested is defined by the size of the aperture screeniing out the radiation. It is a channel with the cross section of the aperture whose length is the height of the test part. The intensity of the radiation identified by the detector is the quantity used to determine the material density. Gamma ray densitometry can equally be performed on green compacts as well as on sintered components. Neither special preparation of test parts nor skilled personnel is required to perform the measurement; neither liquids nor other harmful substances are involved. When parts are exhibiting local density variations, which is normally the case in powder compaction, sectional densities can be determined in different parts of the sample without cutting it into pieces. The test is non-destructive, i.e. the parts can still be used after the measurement and do not have to be scrapped. The measurement is controlled by a special PC based software. All results are available for further processing by in-house quality documentation and supervision of measurements. Tool setting for multi-level components can be much improved by using this test method. When a densitometer is installed on the press shop floor, it can be operated by the tool setter himself. Then he can return to the press and immediately implement the corrections. Transfer of sample parts to the lab for density testing can be eliminated and results for the correction of tool settings are more readily available. This helps to reduce the time required for tool setting and clearly improves the productivity of powder presses. The range of materials where this method can be successfully applied covers almost the entire periodic system of the elements. It reaches from the light elements such as graphite via light metals (AI, Mg, Li, Ti) and their alloys, ceramics ($AI_20_3$, SiC, Si_3N_4, $Zr0_2$, ...), magnetic materials (hard and soft ferrites, AlNiCo, Nd-Fe-B, ...), metals including iron and alloy steels, Cu, Ni and Co based alloys to refractory and heavy metals (W, Mo, ...) as well as hardmetals. The gamma radiation required for the measurement is generated by radioactive sources which are produced by nuclear technology. These nuclear materials are safely encapsulated in stainless steel capsules so that no radioactive material can escape from the protective shielding container. The gamma ray densitometer is subject to the strict regulations for the use of radioactive materials. The radiation shield is so effective that there is no elevation of the natural radiation level outside the instrument. Personal dosimetry by the operating personnel is not required. Even in case of malfunction, loss of power and incorrect operation, the escape of gamma radiation from the instrument is positively prevented.

• Journal of Conservation Science
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• v.24
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• pp.1-11
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• 2008

The Unhyungung Water Container in the possession of the Seoul Museum of History in Korea is consisted of a calcareous marble developed laminated bedding and numerous argillaceous veinlets. This monument should need to conservation treatment because of black discoloration and seriously numerous cracks. Vertical and horizontal cracks in the monument are developed following stratification and argillaceous veinlets that are relatively low coherence between the rock materials. We have proved that the material inducing discoloration on the surface is carbon which is formed by deposited organic matters. As the result of the ultrasonic measurements, although highly surface weathering degree, the physical properties of the Unhyungung Water Container is confirmed slightly weathered state. The depths of cracks in the monument are calculated at maximum 60mm in some cracks completely penetrating into the wall and at minimum 9mm in the other crack. The cracks, developed following veinlet, are revealed that there penetrate from an outer wall to an inside wall for the monument. And most depths of cracks, developed following stratification, are calculated 20 to 30mm. This result will offer a significant data for conservation of the Unhyungung Water Container.

• Design & Manufacturing
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• v.13 no.4
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• pp.10-16
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• 2019

Semiconductor chip is bonded to the substrate by melting solder bumps. In general, the chip bonding is applied by a Reflow process or a Thermo-Compression(TC) bonding process. In this paper, we introduce a Laser Assisted Thermo-Compression bonding (LATCB) process to improve the anxiety of the existing process(Reflow, TC bonding). In the LATCB process, the chip is bonded to the substrate by irradiating a laser with a uniform energy density in the same area as the chip to melt only the solder bumps and press the chip with a Transparent Compression Module (TCM). The TCM consists of a fused silica header for penetrating the laser and pressurizing the chip, and a piezoelectric actuator (P.A.) coupled to both ends of the header for micro displacement control of the header. In addition, TCM is a structure that can pressurize the chip and deliver it to the chip and solder bumps without losing the energy of the laser. Fused silica, which is brittle, is vulnerable to deformation, so the header may be damaged when an external force is applied for pressurization or a displacement differenced is caused by piezoelectric actuators at both ends. On the other hand, in order to avoid interference between the header and the adjacent chip when pressing the chip using the TCM, the header has a notch at the bottom, and breakage due to stress concentration of the notch is expected. In this study, the thickness and notch length that the header does not break when the external force (500 N) is applied to both ends of the header are optimized using structural analysis and Coulomb-Mohr failure theory. In addition, the maximum displacement difference of the P.A.s at both ends where no break occurred in the header was derived. As a result, the thickness of the header is 11 mm, and the maximum displacement difference between both ends is 8 um.