• Journal of Sensor Science and Technology
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• v.30 no.5
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• pp.342-348
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• 2021

For the characterization or failure analysis of electronic devices such as PCB (printed circuit boards), the most common method is the measurement of voltage waveforms with an oscilloscope. However, because there are many types of problems that cannot be detected by voltage waveform analysis, several other methods such as X-ray transmission, infrared imaging, or eddy current measurement have been applied for these analyses. However, these methods have also been limited to general analyses because they are partially useful in detecting physical defects, such as disconnections or short circuits. Fundamentally current waveform measurements during the operation of electronic devices need to be performed, however, commercially available current sensors have not yet been developed, particularly for applications in highly integrated PCB products with sub-millimeter fine pitch. In this study, we developed a highly sensitive PHR (planar hall resistance) magnetic sensor for application in highly integrated PCBs. The developed magnetic sensor exhibited sufficient features of an ultra-small size of less than 340 ㎛, magnetic field resolution of 10 nT, and current resolution of 1 mA, which can be applicable for PCB analyses. In this work, we introduce the development process of the magnetic sensing probe and its characteristic results in detail, and aim to extend this pin-type current probe to applications such as current distribution imaging of PCBs.

• Journal of Environmental Health Sciences
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• v.47 no.2
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• pp.175-181
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• 2021

Objectives: The correlation between the size of a leak hole, the volume of the leakage, and the range of influence was investigated for a hydrochloric acid tank-lorry. Methods: For the case of a tank-lorry chemical accident, KORA (Korea Off-site Risk Assessment Supporting Tool) was used to predict the leak rate and the range of influence according to the size of the leak hole. The correlation was studied using R. Results: As a result of analyzing the leak rate change according to the leak hole size in a 35% hydrochloric acid tank-lorry, as the size of the leak hole increased from 1 to 100 mm, the leak rate increased from 0.008 to 83.94 kg/sec, following the power function. As a result of calculating the range of influence under conditions ranging from 1 to 100 mm in size and 10 to 60 minutes of leakage time, it was found that the range spanned from a minimum of 5.4 m to a maximum of 307.9 m. As a result of multiple regression analysis using R, the quadratic function model best explained the correlation between the size of the leak hole, the leak time, and the range of influence with an adjected coefficient of determination of 0.97 and a root mean square error of 22.33. Conclusion: If a correlation database for the size of a leak hole is accumulated for various substances and under various conditions, the amount of leakage and the range of influence can easily be calculated, facilitating field response activities.

• Ocean policy research
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• v.33 no.2
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• pp.147-181
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• 2018

Currently, we are living in the era of the 4th industrial revolution. In the field of shipping industry, the MASS is a revolutionary game changer in the making arising out of such an industrial and technical innovation in the pursuit of radically challenging the pre-existing system of a human-operated vessel. Given this trend, the entire maritime regulatory regime, which has been designed by, and intertwined with, human seaworthiness, abruptly faces the most unprecedented normative confrontations now and increasingly in the coming days. As the constitution of ocean, UNCLOS, provides, every flag state is obliged to effectively exercise its jurisdiction to secure technical and human seaworthiness. Moreover, the coastal state may institute protective proceedings against vessels in respect of any violations of its laws to protect its marine environment in maritime zones of the coastal state. Further, UNCLOS acknowledges that the port state's authority extends to take administrative measures to prevent sub-standard ships from sailing within the ports or offshore-terminals of the state. These three jurisdictional functions will be required to more closely interface with each other than ever over the legal and political implications created by MASS. Although states' jurisdictional nuances are significant in this present world tilting back to protectionism, there are few articles to present jurisdictional issues of states and conceivable normative discourse with regard to MASS. This articles visits potential jurisdictional conflicts underlying MASS and tries to strike balance between contradictory interpretive approaches under UNCLOS while it is undeniable that this doctrinal research tends to strive to find justifications within the current framework of international law.

• Korean Journal of Materials Research
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• v.29 no.3
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• pp.155-159
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• 2019

Surface plasmon resonance is the resonant oscillation of conduction electrons at the interface between negative and positive permittivity material stimulated by incident light. In particular, when light transmits through the metallic microhole structures, it shows an increased intensity of light. Thus, it is used to increase the efficiency of devices such as LEDs, solar cells, and sensors. There are various methods to make micro-hole structures. In this experiment, micro holes are formed using a wet chemical etching method, which is inexpensive and can be mass processed. The shape of the holes depends on crystal facets, temperature, the concentration of the etchant solution, and etching time. We select a GaAs(100) single crystal wafer in this experiment and satisfactory results are obtained under the ratio of etchant solution with $H_2SO_4:H_2O_2:H_2O=1:5:5$. The morphology of micro holes according to the temperature and time is observed using field emission - scanning electron microscopy (FE-SEM). The etching mechanism at the corners and sidewalls is explained through the configuration of atoms.

• Journal of The Korean Astronomical Society
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• v.51 no.6
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• pp.197-206
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• 2018

We present the analysis of KMT-2016-BLG-0212, a low flux-variation ($I_{flux-var}{\sim}20mag$) microlensing event, which is in a high-cadence (${\Gamma}=4hr^{-1}$) field of the three-telescope Korea Microlensing Telescope Network (KMTNet) survey. The event shows a short anomaly that is incompletely covered due to the brief visibility intervals that characterize the early microlensing season when the anomaly occurred. We show that the data are consistent with two classes of solutions, characterized respectively by low-mass brown-dwarf (q = 0.037) and sub-Neptune (q < $10^{-4}$) companions. Future high-resolution imaging should easily distinguish between these solutions.

• The Journal of the Korea Contents Association
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• v.19 no.7
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• pp.22-35
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• 2019

The purpose of this study is to analyze the applicability and effectiveness of the Person - centered counseling program in the field of counseling service provided by the Independent Living Center for Persons with Disabilities. Thirteen participants, operating peer counseling program at the Independent Living Center who finished 9 sessions of person - centered counseling program over 3 months were interviewed. The collected data were analyzed using Consensual Qualitative Research (CQR). The results were grouped into three themes as "Acceptance as oneself", "Counselor's variables", and "Limitations and unsatisfactory points". Eight categories such as "The relationship with myself and others", "Accepting oneself though with discomfort", "changed perspective about problems", "Recognizing the parts that oneself was not aware", "Accepting one's potentials as well as limitations", "Opportunity to reflect one's life", "Attitude about life ahead" were retrieved with 23 sub-categories. Based on the results, the possibility of applying person - centered approach on peer counseling was presented. Finally, several suggestions for the development of person-centered approach for peer counseling were discussed.

• Journal of Korea Technology Innovation Society
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• v.22 no.3
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• pp.340-361
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• 2019

This study analyzes the technological structure of artificial intelligence (AI) and technological capabilities of AI companies based on patent information. 2589 AI patents registered in USPTO from 2007 to 2017 were collected and analyzed by the Latent Dirichlet Allocation (LDA) to derive 20 AI technology topics. Analysis of technology development trends by AI technology reveals that visual understanding, data analysis, motion control, and machine learning are growing, while language understanding and speech technology are sluggish. In addition, we also investigated leading companies in each sub-field of AI as well as core competencies of global IT companies. The findings of this study are expected to be fruitfully used for formulation and implementation of technology strategy of AI companies.

• BioChip Journal
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• v.12 no.4
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• pp.332-339
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• 2018

The future neuro-prosthetic devices would be required spikes data monitoring through sub-nanoscale transistors that enables to neuroscientists and clinicals for scalable, wireless and implantable applications. This research investigates the spikes monitoring through integrated CNT front-end amplifier for neuro-prosthetic diagnosis. The proposed carbon nanotube-based architecture consists of front-end amplifier (FEA), integrate fire neuron and pseudo resistor technique that observed high electrical performance through neural activity. A pseudo resistor technique ensures large input impedance for integrated FEA by compensating the input leakage current. While carbon nanotube based FEA provides low-voltage operation with directly impacts on the power consumption and also give detector size that demonstrates fidelity of the neural signals. The observed neural activity shows amplitude of spiking in terms of action potential up to $80{\mu}V$ while local field potentials up to 40 mV by using proposed architecture. This fully integrated architecture is implemented in Analog cadence virtuoso using design kit of CNT process. The fabricated chip consumes less power consumption of $2{\mu}W$ under the supply voltage of 0.7 V. The experimental and simulated results of the integrated FEA achieves $60G{\Omega}$ of input impedance and input referred noise of $8.5nv/{\sqrt{Hz}}$ over the wide bandwidth. Moreover, measured gain of the amplifier achieves 75 dB midband from range of 1 KHz to 35 KHz. The proposed research provides refreshing neural recording data through nanotube integrated circuit and which could be beneficial for the next generation neuroscientists.

• The Journal of the Convergence on Culture Technology
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• v.5 no.3
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• pp.33-42
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• 2019

The purpose of this study is to investigate in depth the lived employers experiences of utilizing employment among people with mentally disabilities. Phenomenological approach was used for this study. A total of 9 employer on work of the mentally disabled people were recruited as research participants Data was collected through in-depth interviews from March, 2017 to September, 2018. Transcribed data from audio recordings on interviews were analyzed using the Braun & Clarke method. 6 clustered themes consisting of 12 sub-themes emerged through the qualitative data analysis and they include the following: 1) Getting to realize that a vague concern; 2) Being forced to withstand others' persuasion; 3) Fluctuating on boundaries of my work; 4) Moving forward from individual to team; 5) Being together work expected workers with mentally disabled; and 6) Seeking for company progress. Study findings suggest that expanding employment and improving its quality for work of the mentally disabled people are needed. Additionally, the field of mental health needs an increase in the experiences of employment with expertise in dealing with employers on work of the mentally disabled people.

• The Journal of the Convergence on Culture Technology
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• v.5 no.2
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• pp.1-11
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• 2019

The purpose of this study is to investigate in depth the lived experiences of utilizing supported housing among people with psychiatric disabilities. Phenomenological approach was used for this study. A total of 9 people with psychiatric disabilities were recruited as research participants. Data was collected through in-depth interviews from September, 2016 to March, 2018. Transcribed data from audio recordings on interviews were analyzed using the Colaizzi method. 6 clustered themes consisting of 17 sub-themes emerged through the qualitative data analysis and they include the following: 1) Confusion at site daily residence; 2) Feeling relaxed in supported housing site; 3) Development in self-perception; 4) Undertaking a leading role; 5) Growing capacity for independent living; and 6) Integration into normal life. Study findings suggest that expanding supported housing and improving its quality for people with psychiatric disabilities are needed. Additionally, the field of mental health needs an increase in the number of case managers with expertise in dealing with people suffering from psychiatric disabilities and their recovery.