• Journal of Sensor Science and Technology
• /
• v.20 no.5
• /
• pp.311-316
• /
• 2011

Monitoring the carbon dioxide concentration in arterial blood is vital for the evaluation and prevention of pulmonary disease. Yet, domestic pure arterial blood carbon dioxide sensor technologies are not being developed, instead all sensors are imported. In this paper, we develop a real time monitoring system for arterial blood partial pressure of carbon dioxide($pCO_2$) gas from the wrist by using a carbon micro-heater. The micro-heater was fabricated with a thickness of 0.3 ${\mu}m$ in order to collect the carbon dioxide under the skin. The micro-heater has been designed to perform temperature compensation in order to prevent damage to the skin. Two clinical trials of the system were undertaken. As a result, we demonstrated that a portable, transcutaneous carbon dioxide analysis($TcpCO_2$) device produced domestically is possible. In addition, this system reduced the analysis time significantly. Carbon films could reduce the unit price of these sensors by replacing the gold film used in foreign models. Also, we developed a real time monitoring system which can be used with optical biosensors for medical diagnostics as well as gas sensors for environmental monitoring.

• Journal of the Korean Society of Industry Convergence
• /
• v.12 no.2
• /
• pp.91-97
• /
• 2009

The productivity and the precision machining are the major concerns of the machine tools, and the importance of those features will be even more emphasized with the needs of the modern industries. In this paper the dynamic properties of a lathe have been investigated through the frequency analysis test and the computer simulation to minimize the transmission of vibration generated during the machining process. The modifications have been applied to the original structure to suppress the vibration transmission and further for the structure to achieve less vibrations and higher precision machining. The result shows that the machine can have much less vibrations with simple design alterations for minor expenses, the result can also be readily applied to many similar machines for improved stability.

• Journal of Veterinary Clinics
• /
• v.27 no.1
• /
• pp.83-87
• /
• 2010

Hermaphroditism occurs rarely in human and animal populations. Previously, in Korea, The hermaphrodite dog in American Cocker Spaniel dogs have been reported in six cases. However, in this case, we found a hermaphrodite dog in Korean native Jindo dog. The characteristics were its enlarged os clitoris that was shown a reddish fingerlike structure protruding from the vulva. The dog was diagnosed as hermaphroditism with ovotestes. To our knowledge, this report is the first case of hermaphroditism in Korean native dog.

• Journal of Hydrogen and New Energy
• /
• v.27 no.6
• /
• pp.660-669
• /
• 2016

A fluorinated-sulfonated, hydrophobic-hydrophilic copolymer was planed subsequently synthesized using typical nucleophilic substitution polycondensation reaction. A novel AB and ABA (or BAB) block copolymers were synthesized using sBCPSBP (sulfonated 4,4'-bis[4-chlorophenyl)sulfonyl]-1,1'-biphenyl), DHN (1,5-dihydroxynaphthalene), DFBP (decafluorobiphenyl) and HFIP (4,4'-hexafluoroisopropylidenediphenol). All block copolymers were easily cast and made into clear films. The structure and synthesized copolymers and corresponding membranes were analyzed using GPC (gel permeation chromatography), $^1H$-NMR ($^1H$ nuclear magnetic resonance) and FT-IR (Fourier transform infrared). TGA (Thermogravimetric analysis) and DSC (differential scanning calorimetry) analysis showed that the prepared membranes were thermally stable, so that elevated temperature fuel cell operation would be possible. Hydrophobic/hydrophilic phase separation and clear ionic aggregate block morpology was confirmed in both triblock and diblock copolymer in AFM (atomic force microscopy), which may be highly related to their proton transport ability. A sulfonated BAB triblock copolymer membrane with an ion-exchange capacity (IEC) of 0.6 meq/g has a maximum ion conductivity of 40.3 mS/cm at $90^{\circ}C$ and 100% relative humidity.

• Journal of the Optical Society of Korea
• /
• v.15 no.1
• /
• pp.44-51
• /
• 2011

In this paper, an easy-to-use measurement device for illumination distribution is developed. The device consists of a sensor array module, a control module, and a PC interface. The sensor array module incorporates CIE 1931 color sensors and the ARM-based 96 MHz microcontroller in the control module for measurement and data processing. The sensor array module contains 64 color sensors arranged in a $16{\times}4$ array. The sensitivity of the sensor array module can be adjusted depending on the illumination level to be measured. The measurement data and control signals are exchanged via USB 2.0 standard. To demonstrate the performance of the device, the illumination distribution is measured for colors of red, green, and blue and is graphically shown. The device can be used for measurement of the illumination distribution, design and adjustment of LED illumination.

• Geomechanics and Engineering
• /
• v.17 no.3
• /
• pp.287-294
• /
• 2019

The finite element method (FEM) is widely used to evaluate the seismic performance of pile-supported buildings. However, there are problems associated with modeling the pile end resistance using the FEM, such as the dependence on the mesh size. This paper proposes a new method of modeling around the pile tip to avoid the mesh size effect in two-dimensional (2D) analyses. Specifically, we consider the area of influence around the pile tip as an artificial constraint on the behavior of the soil. We explain the problems with existing methods of modeling the pile tip. We then conduct a three-dimensional (3D) analysis of a pile in various soil conditions to evaluate the area of influence of the soil around the pile tip. The analysis results show that the normalized area of influence extends approximately 2.5 times the diameter of the pile below the pile tip. Finally, we propose a new method for modeling pile foundations with artificial constraints on the nodal points within the area of influence. The proposed model is expected to be useful in the practical seismic design of pile-supported buildings via a 2D analysis.

• Biomedical Science Letters
• /
• v.28 no.1
• /
• pp.34-41
• /
• 2022

In this study, conditions for extraction of functional component from Nypa fruticans wurmb was optimized. The yield by extraction with 30% ethanol (LE30, 42.12%) was higher than those hot water extraction (LDW 33.32%), 50% ethanol (LE50, 40.12%) and 70% ethanol (LE70, 34.5%). The extract was purified and analyzed by GC MS. The prevailing compounds found in extract were Cyclodecasiloxane-, pentadecanoic acid, -eicosane, undecanal and tridecanoic acid. The presence of saturated and unsaturated fatty acids in ethanolic extract vindicate the use of this plant to treat many diseases in traditional medicine. The total phenolic contents in the LDW, LE30, LE50, LE70 extract were 128±1.65 mg/g, 205±2.3 mg/g, 210±4.23 mg/g and 180±5.6 mg/g, respectively. The DPPH was highest in LE70 extract (1,000 ㎍/mL, 81.14%), ABTS was highest in LE50 extract (1,000 ㎍/mL, 84.14%). The protective effects against oxidative stress in raw 264.7 cell imparted by the LE50 extract was better than those imparted by the other extracts. The findings of the present study suggest that 50% ethanol is best solvent for extraction of Nypa fruticans Wurmb, considering yield, polyphenol content, and antioxidant activities with extraction cost.

• Fashion & Textile Research Journal
• /
• v.24 no.2
• /
• pp.217-228
• /
• 2022

The growth of the fashionable hanbok market has led to a significant increase in the number of entrepreneurs or prospective entrepreneurs with small hanbok businesses. To develop the hanbok industry, the public sector is developing and providing education and support programs to enhance the competencies of individual hanbok brand entrepreneurs. This study conducted a survey of 213 subjects such as business operators, workers, and prospective workers in the changing hanbok industry. This study investigated their hanbok education experiences as well as future demands for education and public support programs. To explore differences based on individual characteristics, this study measured such characteristics using entrepreneurial orientation as well as the artistic and entrepreneurial competencies important in running a hanbok brand and analyzed the relationship demand for education and public support. Hanbok brand worker characteristics were classified into four groups based on individual characteristics: "traditionalist," "entrepreneur," "opportunist," and "businessman." Differences existed in terms of detailed education experience and demand as well as demand for public support, depending on the group. The results of this study contribute to development of hanbok curriculums that consider individual characteristics, the effective incubation of new and prospective hanbok brand entrepreneurs, as well as the research on founding small-scale fashion businesses.

• Journal of Environmental Health Sciences
• /
• v.48 no.1
• /
• pp.19-27
• /
• 2022

The industrial development and socioeconomic structures of a society are inextricably linked to occupational accidents and diseases. Since the 1970s, a series of major occupational diseases have occurred in South Korea, such as mercury poisoning in Munsong-myeon, carbon disulfide poisoning at Wonjin Rayon, and leukemia at Samsung Electronics. These incidents have caused us to take a critical look at the level of worker safety and health management within companies and the government. These serve as symbolic and representational events. Doctors, lawyers, and labor activists concerned about employee safety and lives came together for years to struggle with the government and industry in order to determine what caused the diseases and to obtain compensation for victims. They finally achieved recognition for occupational diseases and recompense for losses. It is difficult to find similar cases to the baby powder asbestos talc cases and the radon bed case internationally, or there is no case where such a large number of consumers have been potentially harmed. It is also difficult to prove that the damage took place due to the victims' diverse geographic locations and ages, as well as the disease's long incubation period. Based on this premise, businesses and the government have been apathetic in acknowledging these diseases and compensating for damages, with few practical outcomes. Furthermore, unlike the large-scale occupational disease cases, only a few people including expert groups were organized and actively participated in the settlement of these issues, so it remains unfinished business for our society to address.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.17 no.1
• /
• pp.177-189
• /
• 2022

This study proposes policy recommendations for the Korea New Exchange ("KONEX"), which is a financial platform for SMEs and startups that relied on indirect and policy financing in the past. SMEs and venture firms with limited human and physical listing resources can grow through market incubation, and venture capitalists expect an early exit or return on investment. However, the lack of liquidity and sluggish trading volume have weakened the function of the market. Despite prior policy efforts, the number of newly listed companies has decreased while listing demand for KOSDAQ and K-OTC has increased. This study aims to suggest short- and long-term improvements in regulations and throughout the KONEX firms' listing life cycle. First, the minimum deposit requirement on individual investors should be abolished to increase the number of investors. Second, information disclosure should be conducted by firms so that the nominated advisor can focus on discovering and supporting new listed companies. Third, in order to increase trading volume, the 5% dispersion rule should be changed to 25% dispersion incentive principle. Fourth, a new track without profit condition in expedited transfer listing should be introduced because the KOSDAQ relaxes the profit realization requirements for listing. Lastly, transfer listing without additional review for firms that fulfill ownership dispersion, information disclosure, and investor protection will strengthen the incubating role of the KONEX.