• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.789-792
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• 2003

pMOSFET having 10 ${\mu}um$ thickness Gd layer has been tested to be used as a slow neutron sensor. The total thermal neutron cross section for the Gd is 47,000 barns and the cross section value drops rapidly with increasing neutron energy. When slow neutrons are incident to the Gd layer, the conversion electrons are emitted by the neutron absorption process. The conversion electrons generate electron-hole pairs in the $SiO_2$ layer of the pMOSFET. The holes are easily trapped in Oxide and act as positive charge centers in the $SiO_2$ layer. Due to the induced positive charges, the threshold turn-on voltage of the pMOSFET is changed. We have found that the voltage change is proportional to the accumulated slow neutron dose, therefore the pMOSFET having a Gd nuclear reaction layer can be used for a slow neutron dosimeter. The Gd-pMOSFET were tested at HANARO neutron beam port and $^{60}CO$ irradiation facility to investigate slow neutron response and gamma response respectively. Also the pMOSFET without Gd layer were tested at same conditions to compare the characteristics to the Gd-pMOSFET. From the result, we have concluded that the Gd-pMOSFET is very sensitive to the slow neutron and can be used as a slow neutron dosimeter. It can also be used in a mixed radiation field by subtracting the voltage change value of a pMOSFET without Gd from the value of the Gd-pMOSFET.

• Korea and Global Affairs
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• v.1 no.2
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• pp.5-32
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• 2017

5.18 Gwangju Democratization Movement was approved as a legal democratization movement by president Kim Young Sam in May 1993 and was approved as a global recording inheritance by UNESCO in May 2011 for the honor of Gwangju citizens to be restored. However, assessment on this until today after 35 years of occurrence is not nationally unified and the mind of Gwangju maybe only remembered as pride by Gwangju. There are several factors of this continuing situation but this researcher thinks the biggest factor is that professionals reanalyzing the truth ascertainment fitting spirit of the times who are in charge of citizen education are intensively distributed in Jeolla-do and Seoul. Moreover, the journal unlikely assessing 5.18 have enemies in the assailant area during activity that unity is not taking place with divided assessments and trapped in Honam. This study judges that the reason the meaning of 5.18 is trapped in Honam and not nationally unified is because of the limit of "adversary system." Especially researchers who should analyze and explain this incident in a objective views are bias distributed (Gwangju Jeolla-do> Seoul>Gyeongnam) in hometown areas that the possibility of 5.18 meaning not being unified was focused. Academic research studies, journal writers, and publication locations are divided in this study to reveal they are bias distributed and reveal that there is possibility that this biased distribution of researches are becoming obstacles in overcoming regionality.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.36D no.10
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• pp.9-16
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• 1999

When the conventional IPD (inter-poly-dielctrics) layer with ONO(oxide-nitride-oxide) structure was used in the Flash EEPROM cell, its data retention characteristics were significanfly degraded because the top oxide of the ONO layer was etched off due to the cleaning process used in the gate oxidation process for the peripheral MOSFETs. When the IPD layer with the ONON(oxide-nitride-oxide-nitride) was used there, however, its data retention characteristics were much improved because the top nitride of the ONON layer protected the top oxide from being etched in the cleaning process. For the modelling of the data retention characteristics of the Flash EEPROM cell with the ONON IPD layer, the decrease of the threshold voltage cue to the charge loss during the bake was here given by the empirical relation ${\Delta}V_t\; = \;{\beta}t^me^{-ea/kT}$ and the values of the ${\beta}$=184.7, m=0.224, Ea=0.31 eV were obtained with the experimental measurements. The activation energy of 0.31eV implies that the decrease of the threshold voltage by the back was dur to the movement of the trapped electrons inside the inter-oxide nitride layer. On the other hand, the results of the computer simulation using the model were found to be well consistent with the results of the electrical measurements when the thermal budget of the bake was not high. However, the latter was larger then the former in the case of the high thermal budger, This seems to be due to the leakage current generated by the extraction of the electrons with the bake which were injected into the inter-oxide niride later and were trapped there during the programming, and played the role to prevent the leakage current. To prevent the generation of the leakage current, it is required that the inter-oxide nitride layer and the top oxide layer be made as thin and as thick as possible, respectively.

• Proceedings of the ESK Conference
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• 1992.10a
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• pp.63-67
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• 1992

인간이 역사를 이루며 살아오면서 피복은 인간의 생활 수단으로서 빠뜨릴 수 없는 존재가 되었다. 사외 생활을 하면서 인간은 자신을 보호하고 남에게 자신의 이미지를 전달하고 자신의 욕구를 표출하면서 만족시키는데 있어 의복은 가장 중요한 역활을 하고 있고 인간 역시 그러한 것들을 의복에 의존하고 있는 것이다. 그러나 정상인을 위한 의복만 취급되어지는 시장에서 신체장애자들은 정상인보다도 더 세심하게 기능들이 고려된 의복이 필요함에도 불구하고 의복의 기능들을 생각하면서 의복을 선택할 수가 없다. 이러한 사앙들이 대두되면서 현대에 들어 신체 장애자 의복에 있어서 불편함을 없애고 보다 적합한 의복을 만들기 위한 연구가 진행되었다. 신체 장애자의 의복 연구는 Ward가 이 부분에 관심을 표명한 이후 임상 의사들에 의해 연구가 이루어지기 시작했다. 우리나라에서도 1976년 심성식의 한국 신체 장애자의 의복에 관한 연구를 기점으로 이 분야의 관심도가 높아지고 있으나 아직까지는 전반적으로 부족한 실정이다. 특히 위생적인 분야에서는 자료가 매우 부족하다. 이에 본 연구에서는 휠체어를 사용하는 하지 마비자의 체표 면을 떠서 기성복 패턴과 비교를 통해 보다 편안한 바지 패턴을 제시하고, 여름철에 많이 사용하는 직물로 바지를 제작하고 착용시킨후 인체 생리 반응을 분석하여 여름철에 쾌적한 바지를 알아 보았다. 이 연구를 통해 일반인과는 생활 자세가 다른 휠체어를 사용하는 하지 마비자와 일반인이 입는 기성복 바지를 착용 했을 때 생기는 불합리한 요소들을 고려하여 미적이고 기능적 및 위생적인 측면에서 신체 장애자에게 보다 적합한 바지를 제작하기 위한 기초 자료를 제공하고자 한다.값은 $f^{m}$ (p-1)-1 이다. (n=2m)이 많고 흡연 등의 만성 자극 요인이 있으며 술후 음성 호전에 걸리는 기간이 길어 보다 복합적인 측면에서 치료에 임하여야 할 것으로 사료된다. with such configuration.trap with 2.88[eV] deep of injected space charge from the chathode in the crystaline regions. The origin of ${\alpha}$$_2$ peak was regarded as the detrapping process of ions trapped with 0.9[eV] deep originated from impurity-ion remained in the specimen during production process of the material, in the crystalline regions. The origin of ${\beta}$ peak was concluded to be due to the depolarization process of "C=0"dipole with the activation energy of 0.75[eV] in the amorphous regions. The origin of ${\gamma}$ peak was responsible to the process combined with the depolarization of "CH$_3$", chain segment, with the activation

• JSTS:Journal of Semiconductor Technology and Science
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• v.12 no.4
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• pp.449-457
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• 2012

The program/erase (P/E) cyclic endurances including bias temperature instability (BTI) behaviors of Metal-$Al_2O_3$-Nitride-Oxide-Semiconductor (MANOS) memories are investigated in comparison with those of Semiconductor-Oxide-Nitride-Oxide-Semiconductor (SONOS) memories. In terms of BTI behaviors, the SONOS power-law exponent n is ~0.3 independent of the P/E cycle and the temperature in the case of programmed cell, and 0.36~0.66 sensitive to the temperature in case of erased cell. Physical mechanisms are observed with thermally activated $h^*$ diffusion-induced Si/$SiO_2$ interface trap ($N_{IT}$) curing and Poole-Frenkel emission of holes trapped in border trap in the bottom oxide ($N_{OT}$). In terms of the BTI behavior in MANOS memory cells, the power-law exponent is n=0.4~0.9 in the programmed cell and n=0.65~1.2 in the erased cell, which means that the power law is strong function of the number of P/E cycles, not of the temperature. Related mechanism is can be explained by the competition between the cycle-induced degradation of P/E efficiency and the temperature-controlled $h^*$ diffusion followed by $N_{IT}$ passivation.

• Proceedings of the KIEE Conference
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• 1998.07d
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• pp.1373-1376
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• 1998

Electroluminescent(EL) devices based on organic materials have been of great interest due to their possible applications for large-area flat-panel displays. They are attractive because of their capability of multicolor emission, and low operation voltage. In this study, glass substrate/ITO/TPD/$Eu(TTA)_3(phen)/Alq_3/Al$ structures were fabricated by evaporation method, where aromatic diamine(TPD) were used as a hole transporting material, $Eu(TTA)_3(phen)$ as an emitting material, and tris(8-hydroxyquinoline)Aluminum ($Alq_3$) as an electron transporting layer. Electroluminescent(EL) and I-V characteristics of $Eu(TTA)_3(phen)$ with a variety thickness was investigated. This structure shows the red EL spectrum, which is almost the same as the PL spectrum of $Eu(TTA)_3(phen)$. I-V characteristics of this structure show that turn-on voltage was 9V and current density of $0.01A/cm^2$ at a dc drive voltage of 9V. Details on the explanation of electrical transport phenomena of these structures with I-V characteristics using the trapped-charge-limited current model will be discussed.

• Composites Research
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• v.29 no.4
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• pp.179-185
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• 2016

A self-charging supercapacitor is constructed through simple integration of the energy storage and photo exited materials at the photo electrode. The large band gap of $NiO/Fe_3O_4$ heterostructure generates photo electron at the photo electrode and store the charges through redox mechanism at the counter electrode. Sulfanilic acid azocromotrop/reduced graphene oxide layer at the photo electrode trapped the photo generated hole and store the charge by forming double layer. The solar supercapacitor device is charged within 400 s up to 0.5 V and exhibited a high specific capacitance of ~908 F/g against 1.5 A/g load. The solar illuminated supercapacitor shows a high energy and power density of 33.4 Wh/kg and 385 W/kg along with a very low relaxation time of ~15 ms ensuring the utility of the self charging device in the various field of energy storage and optoelectronic application.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1992.11a
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• pp.34-37
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• 1992

In this paper, the $(SrPb)(CaMg)TiO_3$-xBi_2O_3{\cdot}3TiO_2$ ceramics with paraelectric properties were fabricated by the mixed oxide method. In order to investigate the behavior of charged particles, the characteristics of electrical conduction and thermally stimulated current were measured respectively. As a result on characteristics of the electrical conduction, the leakage current was increased as measuring temperature was increased. At room temperature, the conduction current was divided into the three steps as a function of DC electric field. The first step was Ohmic region due to ionic conduction, below 15[kV/cm]. The second step was showed a saturation which seems to be related to a depolarizing field occuring in field-enforced ferroelectric phase, between 15[kV/cm] and 40[kV/cm]. The third step was attributed to Child's law related to spare charge which injected from electrode, above 40[kV/cm]. Thermally stimulated currents(TSC) spectra with various biasing fields exhibited three distinguished peaks that were denoted as ${\alpha}$, ${\alpha}'$ and ${\beta}$ peak, each of which appeared at nearby -30, 20 and 95[$^{\circ}C$] respectively. It is confirmed that the a peak was due to trap electron trapped in the grainboundary, and ${\alpha}'$ peak that was observed above only 1.5[kV/mm] was attributed to field-enforced ferroelectric polarization. The origin of ${\beta}$ peak was identified as ion migration which caused the degradation.

• 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.

• Journal of the Korean Magnetics Society
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• v.16 no.4
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• pp.206-210
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• 2006

A room-temperature ferromagnetism has been observed for oxygen-deficient rutile and anatase $TiO_{2-{\delta}}$ films. XPS data revealed the existence of $Ti^{3+}$ ions, for compensating the charge imbalance caused by oxygen vacancies in the film. The observed ferromagnetism is attributable to the spin ($3d^1$) alignment of the $Ti^{3+}$ ions. Such spin alignment can happen through magnetic polaron formed by trapped electron in oxygen vacancy and magnetic $Ti^{3+}$ ions around it.