• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.11
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• pp.1631-1636
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• 2010

In this study, we demonstrate a nano-scale lithograph obtained on localized (100) silicon (p-type) surface using by modified AFM (Atomic force microscope) apparatuses and by adopting controlling methods. AFM-based experimental apparatuses are connected to a customized pulse generator that supplies electricity between the conductive tip and the silicon surface, while maintaining a constant humidity throughout the lithography process. The pulse durations are controlled according to various experimental conditions. The electrochemical reaction induced by the pulses occurs in the gap between the conductive tip and silicon surface and result in the formation of nanoscale oxide particles. Oxide particles with various heights and widths can be created by AFM surface modification; the size of the oxide particle depends on the pulse durations and the applied electrical conditions under a humid environment.

• Archives of Plastic Surgery
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• v.35 no.3
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• pp.312-315
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• 2008

Purpose: Amelanotic melanoma represents a melanoma with an absence or a small number of melanin pigments and comprises 2% of all melanomas. These melanomas are frequently misdiagnosed, probably because of its nonspecific clinical features and difficulty in diagnosis, resulting in delayed diagnosis and treatment. We report a patient with amelanotic melanoma, who underwent surgical treatment with sentinel lymph node biopsy using gamma probe. Methods: A 32-year-old female was presented with a slowly growing ill-defined, hypopigmented nonerythematous lesion with nail defect on right index finger tip. Preoperative punch biopsy was performed, showing an amelanotic melanoma. Sentinel lymph node biopsy was done using gamma probe(Crystal probe system, CRYSTAL PHOTONICS GmbH, Germany) and confirmed no evidence of regional lymph node metastases. The patient underwent amputation at the proximal interphalangeal joint. Results: Histopathologic findings showed superficial spreading melanoma. There were no melanin pigments in Hematoxylin & Eosin stain but positive immunohistochemical stainings for S-100 protein and Hmb45, which were consistent with amelanotic melanoma. Patient's postoperative course was uneventful without any complication and had no evidence of recurrence of tumor in 6 months follow-up period. Conclusion: Amelanotic melanoma is extremely rare subtype of malignant melanoma with histopathologic findings of atypical melanocytes without melanin pigments. Early detection is crucial since survival is strongly related to tumor thickness and tissue invasion at the time of diagnosis. Wide excision is the treatment of choice and other conjunctive therapy has not been successful.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.54 no.10
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• pp.438-442
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• 2005

Si nanocrystal (Si NC) memory device has several advantages such as better retention, lower operating voltage, reduced punch-through and consequently a smaller cell area, suppressed leakage current. However, the physical and electrical reasons for this behavior are not completely understood but could be related to interface states of Si NCs. In order to find out this effect, we characterized electrical properties of Si NCs embedded in a SiO$_{2}$ layer by scanning probe microscopy (SPM). The Si NCs were generated by the laser ablation method with compressed Si powder and followed by a sharpening oxidation. In this step Si NCs are capped with a thin oxide layer with the thickness of 1$\~$2 nm for isolation and the size control. The size of 51 NCs is in the range of 10$\~$50 m and the density around 10$^{11}$/cm$^{2}$ It also affects the interface states of Si NCs, resulting in the change of electrical properties. Using a conducting tip, the charge was injected directly into each Si NC, and the image contrast change and dC/dV curve shift due to the trapped charges were monitored. The results were compared with C-V characteristics of the conventional MOS capacitor structure.

• Current Optics and Photonics
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• v.7 no.1
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• pp.38-46
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• 2023

Optical Fourier-domain reflectometry (OFDR) sensors have been widely used to measure distances with high resolution and speed in a noncontact state. In the electroplating process of a printed circuit board, it is critically important to monitor the copper-plating thickness, as small deviations can lead to defects, such as an open or short circuit. In this paper we employ a phase-based OFDR sensor for in situ relative distance sensing of a sample with nanometer-scale resolution, during electroplating. We also develop an optical-path difference (OPD)-regulated sensing probe that can maintain a preset distance from the sample. This function can markedly facilitate practical measurements in two aspects: Optimal distance setting for high signal-to-noise ratio OFDR sensing, and protection of a fragile probe tip via vertical evasion movement. In a sample with a centimeter-scale structure, a conventional OFDR sensor will probably either bump into the sample or practically out of the detection range of the sensing probe. To address this limitation, a novel OPD-regulated OFDR system is designed by combining the OFDR sensing probe and linear piezo motors with feedback-loop control. By using multiple OFDR sensors, it is possible to effectively monitor copper-plating thickness in situ and uniformize it at various positions.

• Journal of the Korean Society for Nondestructive Testing
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• v.18 no.6
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• pp.455-463
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• 1998

RCCA(rod cluster control assembly) End-Tip suffers from neutron irradiation and constant vibration due to high-speed internal flow of primary coolant during plant operation. Such operating conditions cause the RCCA end-tip crackings around tile circumferential weldment of the end-tip, and in some cases, the defective end-tips were completly broken loose. However, no reliable inspection techniques for end-tip crackings were developed in the past, although some techniques exist for inspecting RCCA control rod wears. Therefore, NDE group at KEPRI has developed an ECT technique for the detection and the sizing of the end-tip crackings. The technique uses a specially designed surface-riding probe that can detect size of circumferential crackings with an accuracy of ${\pm}5.31%$ RMS error. This paper describes the ECT instrumentation including the ECT probes, calibration bars, as well as technical approaches.

• Journal of the Microelectronics and Packaging Society
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• v.20 no.2
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• pp.11-15
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• 2013

The wafer bonding process becomes a flexible approach to material and device integration. The bonding strength in 3-dimensional process is crucial factor in various interface bonding process such as silicon to silicon, silicon to metals such as oxides to adhesive intermediates. A measurement method of bonding strength was proposed by utilizing AFM applied CNT probe tip which indicated the relative simplicity in preparation of sample and to have merit capable to measure regardless type of films. Also, New Tool was utilized to measure of tip radius. The cleaned $SiO_2$-Si bonding strength of SPFM indicated 0.089 $J/m^2$, and the cleaning result by RCA 1($NH_4OH:H_2O:H_2O_2$) measured 0.044 $J/m^2$, indicated negligible tolerance which verified the possibility capable to measure accurate bonding strength. And it could be confirmed the effective bonding is possible through SPFM cleaning.

• The Korean Journal of Pain
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• v.7 no.2
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• pp.217-221
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• 1994

Percutaneous neurolysis of upper thoracic sympathetic ganglion was performed in 40 patients by simultaneously injecting 3 ml of pure alcohol into the T2 and T3 levels after 3 ml of injection of local anesthetic agent on the same sites. Using a skin temperature probe, finger tip temperatures were measured on the index finger ipsilateral to the nerve block before block, 15 and 30 minutes after test block, and 30 minutes after alcohol block. Alcohol block was performed immediately after 30 minutes test block. Finger tip temperatures obtained at 30 minutes post alcohol block and test block and the differences in the temperatures measured before and 30 minutes after alcohol block were shown to be statistically important as potential indicators for prediciting long term outcome of therapy for palmar hyperhidrosis using this technique. These results demonstrate that the palmar temperature monitoring method is sufficiently sensitive to predict the outcome of nerve block during and after thoracic sympathetic ganglion block.

• Clinics in Shoulder and Elbow
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• v.22 no.3
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• pp.146-148
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• 2019

We report a simple technique for repairing capsular tear, using only a hook-like, cannulated instrument and braided sutures without relaying steps. A No. 2 braided suture is passed through the lumen of the instrument. Under direct arthroscopic view, the tip of the instrument is passed through the side of the capsule that has previously been separated with the probe. One end of the suture is retrieved with a grasper through a separate portal. The tip is moved back without withdrawing through the skin, and reinserted into the other side of the capsule. Holding the end retrieved earlier, the other end of the suture is retrieved with a suture retriever. After complete removal of the instrument, the suture is tied through a cannula using the standard knot tying techniques. The same procedures are repeated for other required knots.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.10
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• pp.1210-1218
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• 2004

Experimental study was performed to investigate the flow behavior in boundary layer on the blade suction surface of a multi-stage axial flow compressor, which was focused on the third stage of the 4-stage Low Speed Research Compressor. Flow measurements in the boundary layer were obtained using a boundary layer hot wire probe, which was traversed normal to the blade suction surface at small increments by the probe traverse specially designed. Detailed boundary layer flow measurements covering most of the stator suction surface were taken and are described using time mean and ensemble averaged velocity profiles. Amplitude of the velocity fluctuation and turbulence intensity in the boundary layer flow are also discussed. At midspan, narrow but strong wake zone due to passing wake disturbances is generated in the boundary layer near the blade leading edge for the rotor blade passing period. Corner separation is observed at the tip region near the trailing edge, which causes to increase steeply the boundary layer thickness.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.12
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• pp.145-150
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• 2000

Micro punching is one of general methods to fabricate simple holes such as permanent ink-jet printer nozzles. A thin punch, that is need for micro punching, usually has been obtained by mechanical machining. There are some method to obtain a thin punch from a cylindrical rod, e.g., microgrinding and WEDG (Wire Electro-Discharge Grinding). Inefficiently, only one punch can be obtained from these machining methods. In contrast with these methods, many punches can be fabricated simultaneously by electrochemical process. Electrochemical process has usually aimed to obtain very sharp probe for atomic force microscopy (AFM) or scanning tunneling microscopy (STM), and it has not been considered the whole shape of a probe in spite of good merits. In this paper, an ultrathin punch with a tapered shape and a cylindrical tip is newly fabricated by electrochemical process.