• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.52 no.1
• /
• pp.56-64
• /
• 2016

This study analyzed characteristics of officers' watch-keeping during fishing operation at the fisheries training ship KAYA (GT: 1,737 tons, Pukyong National University). It observed fishing works of three officers in wheel house of KAYA. The observations were carried out at the fishing ground 45 miles away from east of Jeju from 7 to 8 January 2010. The works and movements of the officers were recorded with three common video cameras and a 4-channel MPEG-4 Triplex DVR. Recorded data of the working circulation was analyzed by using the post-processing method. As a result of the traffic lines, the average (${\pm}S.D$) of working hour (min) and moving frequency (times), distance (m) and speed (m/min) during setting the net was 11.8 (0.9), 43.7 (8.1), 133.9 (35.8) and 10.5 (0.6), respectively. During trawling the net, it was 100, 241 (39.8), 615.7 (194.6) and 5.2 (1.6), respectively. During hauling the net, it was 17.6 (1.4), 41.0 (7.2), 196.9 (37.6) and 10.7 (0.8), respectively. In addition, it has a different tendency of the instrument usage frequency by the fishing works. During setting, the usage priority was CCTV, ECDIS, RPM and pitch controller, net monitor, GPS plotter, chart room, X-band radar, fish finder and public addressor. During trawling, it was CCTV, ECDIS, fish finder, X-band radar, net monitor, chart room, GPS plotter, RPM and pitch controller, auto pilot and steering, interphone, wind speed and direction indicator, No.1. VHF, navigation light control panel and public addressor. During hauling, it was CCTV, RPM and pitch controller, GPS plotter, public addressor, chart room, net monitor, X-band radar, auto pilot and steering and fish finder.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2014.02a
• /
• pp.304.1-304.1
• /
• 2014

Flat-panel displays have been growing as an essential everyday product in the current information/communication ages in the unprecedented speed. The forward-coming applications require light-weightness, higher speed, higher resolution, and lower power consumption, along with the relevant cost. Such specifications demand for a new concept-based materials and applications, unlike Si-based technologies, such as amorphous Si and polycrystalline Si thin film transistors. Since the introduction of the first concept on the oxide-based thin film transistors by Hosono et al., amorphous oxide thin film transistors have been gaining academic/industrial interest, owing to the facile synthesis and reproducible processing despite of a couple of shortcomings. The current work places its main emphasis on the binary oxides composed of ZnO and SnO2. RF sputtering was applied to the fabrication of amorphous oxide thin film devices, in the form of bottom-gated structures involving highly-doped Si wafers as gate materials and thermal oxide (SiO2) as gate dielectrics. The physical/chemical features were characterized using atomic force microscopy for surface morphology, spectroscopic ellipsometry for optical parameters, X-ray diffraction for crystallinity, and X-ray photoelectron spectroscopy for identification of chemical states. The combined characterizations on Zn-Sn-O thin films are discussed in comparison with the device performance based on thin film transistors involving Zn-Sn-O thin films as channel materials, with the aim to optimizing high-performance thin film transistors.

• Journal of Powder Materials
• /
• v.24 no.6
• /
• pp.464-471
• /
• 2017

A metal mesh TCE film is fabricated using a series of processes such as UV imprinting of a transparent trench pattern (with a width of $2-5{\mu}m$) onto a PET film, filling it with silver paste, wiping of the surface, and heat-curing the silver paste. In this work nanosized (40-50 nm) silver particles are synthesized and mixed with submicron (250-300 nm)-sized silver particles to prepare silver paste for the fabrication of metal mesh-type TCE films. The filling of these silver pastes into the patterned trench layer is examined using a specially designed filling machine and the rheological testing of the silver pastes. The wiping of the trench layer surface to remove any residual silver paste or particles is tested with various mixture solvents, and ethyl cellosolve acetate (ECA):DI water = 90:10 wt% is found to give the best result. The silver paste with 40-50 nm Ag:250-300 nm Ag in a 10:90 wt% mixture gives the highest electrical conductance. The metal mesh TCE film obtained with this silver paste in an optimized process exhibits a light transmittance of 90.4% and haze at 1.2%, which is suitable for TSP application.

• Journal of Labour Economics
• /
• v.23 no.2
• /
• pp.127-151
• /
• 2000

The empirical study that used the logit model and the Heckman's selection bias model based upon 'Korea Labor & Income Panel Study' shows that the experience of job training has a positive effect on the probability of employment, as well as on the wage increase. The analysis also sheds light on the effect on employment with wage workers who experienced job training. When the discouraged unemployed are not classified as labor force participants, that is the unemployed, and the industrial dummy variables are excluded, logit estimation shows that training program in the public sector, not in the private sector, significantly increases their employment probability. However when these same workers are classified as the unemployed and the industrial dummies are included, logit estimation shows that public and private training programs has no effect on their employability.

• Proceedings of the Korean Society of Applied Pharmacology
• /
• 1998.11a
• /
• pp.89-94
• /
• 1998

Marine sponges are recognized as a plentiful source of diverse biologically active secondary metabolites. Recently, we have initiated a research to discover antitumor constituents from the marine sponges collected from Korean Waters. Marine sponges collected from the South Sea of Korea were screened for several biological activities including such as brine shrimp lethality and cytotoxicity. Significant brine shrimp lethality was detected in the crude extract of a two-sponge association of Poecillastra sp. and Jaspis sp. A cross-section of this sample showed two layers of morphologically distinct sponges. The thin and dirty yellow outer layer was identified as Poecillastra sp. (Pachastrellidae), the surface of which was very rough. The light-grey inner layer was identified as Jaspis sp. (Jaspidae), the surface of which was smooth. This two-sponge association appears to be consistent as these sponges were always found in associated form regardless of collection site or collection period. Investigation of the bioactive constituents monitored by brine shrimp lethality assay led to the isolation of pectenotoxin II (PTX2) and psammaplin A as causative compounds for the brine shrimp lethality. $^1$H- and $\^$13/C-nmr signals of PTX2 was fully assigned utilizing TOCSY, HETCOR, Long-range HETCOR, and Homonuclear J-resolved 2D experiments. PTX2 displayed very potent and selective cytotoxicities in the 60 cell line panel antitumor assay at the NCI. PTX2 has progressed to acute toxicity determination and in vivo antitumor assay at the NCI (Table 1). However, significant in vitro antitumor activity of PTX2 can not be affirmed in the in vivo assay.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.41 no.6
• /
• pp.525-532
• /
• 2017

The development of an inkjet-based manufacturing machine for the production of next-generation displays using organic and quantum-dot light emitting diodes at a low cost has been conducted. To employ inkjet printing in production lines of displays, the development of a high-speed inkjet-monitoring device to verify the reliable droplet jetting status from multiple nozzles is required. In this study, an inkjet monitoring device using a rotatable mirror with rotary and linear ultrasonic motors is developed in place of a conventional, linear reciprocating, motion-based inkjet monitoring device. Its performance is also demonstrated. The measurements of circular patterns with diameters of $10{\mu}m$, $30{\mu}m$, and $50{\mu}m$ are performed with the accuracies of $0.5{\pm}1.0{\mu}m$, $-1.2{\pm}0.3{\mu}m$, and $0.2{\pm}0.5{\mu}m$, respectively, within 17 sec. By optimizing the control program, the takt time can be reduced to as short as 8.6 sec.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2011.02a
• /
• pp.199-199
• /
• 2011

Recently, Thin film transistors (TFTs) with amorphous oxide semiconductors (AOSs) can offer an important aspect for next generation displays with high mobility. Several oxide semiconductor such as ZnO, $SnO_2$ and InGaZnO have been extensively researched. Especially, as a well-known binary metal oxide, tin oxide ($SnO_2$), usually acts as n-type semiconductor with a wide band gap of 3.6eV. Over the past several decades intensive research activities have been conducted on $SnO_2$ in the bulk, thin film and nanostructure forms due to its interesting electrical properties making it a promising material for applications in solar cells, flat panel displays, and light emitting devices. But, its application to the active channel of TFTs have been limited due to the difficulties in controlling the electron density and n-type of operation with depletion mode. In this study, we fabricated staggered bottom-gate structure $SnO_2$-TFTs and patterned channel layer used a shadow mask. Then we compare to the performance intrinsic $SnO_2$-TFTs and doping hafnium $SnO_2$-TFTs. As a result, we suggest that can be control the defect formation of $SnO_2$-TFTs by doping hafnium. The hafnium element into the $SnO_2$ thin-films maybe acts to control the carrier concentration by suppressing carrier generation via oxygen vacancy formation. Furthermore, it can be also control the mobility. And bias stability of $SnO_2$-TFTs is improvement using doping hafnium. Enhancement of device stability was attributed to the reduced defect in channel layer or interface. In order to verify this effect, we employed to measure activation energy that can be explained by the thermal activation process of the subthreshold drain current.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2012.02a
• /
• pp.450-450
• /
• 2012

In recent days, advances in ZnO-based oxide semiconductor materials have accelerated the development of thin-film transistors (TFTs), which are the building blocks for active matrix flat-panel displays including liquid crystal displays (LCD) and organic light-emitting diodes (OLED). In particular, the development of high-mobility ZnO-based channel materials has been proven invaluable; thus, there have been many reports of high-performance TFTs with oxide semiconductor channels such as ZnO, InZnO (IZO), ZnSnO (ZTO), and InGaZnO (IGZO). The reliability of oxide TFTs can be improved by examining more stable oxide channel materials. In the present study, we investigated the effects of an ALD-deposited water vapor permeation barrier on the stability of ZnO and HfZnO (HZO) thin film transistors. The device without the water vapor barrier films showed a large turn-on voltage shift under negative bias temperature stress. On the other hand, the suitably protected device with the lowest water vapor transmission rate showed a dramatically improved device performance. As the value of the water vapor transmission rate of the barrier films was decreased, the turn-on voltage instability reduced. The results suggest that water vapor related traps are strongly related to the instability of ZnO and HfZnO TFTs and that a proper combination of water vapor permeation barriers plays an important role in suppressing the device instability.

• The Korean Journal of Food And Nutrition
• /
• v.11 no.2
• /
• pp.216-220
• /
• 1998

To maintain flavor and color of fresh green pepper, the fresh green pepper paste was directly prepared from fresh green pepper. The characteristic of fresh green pepper paste and processing properties were investigated, and the effect of salt, glucose, acid and heat on product quality during processing and storage were studied. After the processed fresh green pepper paste was stored at 3$0^{\circ}C$ and 5$^{\circ}C$ without light for 6 months. The weight and pH of pericarp were 86% of total and 4.5~5.0, respectively. Addition of 10% salt, 5% glucose, and 0.1 dl-malic acid to the fresh green pepper paste maintain flavor of fresh green pepper could be preserved for 6 months at 5$^{\circ}C$. Panel test showed fresh green pepper paste which was made of 10% salt, 5% glucose and 0.1% dl-malic acid to the fresh green pepper was quite acceptable.

• Korea Journal of Hospital Management
• /
• v.22 no.2
• /
• pp.58-69
• /
• 2017

Recently, with the increase in the number of private health insurance subscribers, interest in overuse of the medical service is increasing. This study analyzed the impacts of private health insurance (PHI) on medical institution selection in outpatient service utilization among persons with arthritis. In order to control patients' health status, we extracted outpatient episodes with the same disease (KCD6, M13) from Korea Health Panel. The unit of analysis was an outpatient visit with arthritis in 2014 (n=23,363). In the light of insurance coverage, we redefined three type of private health insurance (ex, indemnity, fixed benefit, and non-insured) as a test variable and two type of medical institution (ex, hospital and physician visit) as a dependent variable. We conducted a probit regression analysis to identify the impacts of PHI on medical institution selection controlling for heteroscedasticity. The results of this study showed that the insured with indemnity were more likely to choose hospital departments than clinics (marginal effect=0.0475, p=0.000). The impact of participation of fixed benefit PHI was not as clear as that of indemnity type (marginal effect=0.0162, p=0.047). In conclusion, this study confirmed that PHI, particularly indemnity type has a significant impact on the selection of medical institutions. Healthcare policy makers should consider that PHI not only affects the overall quantitative increase in healthcare utilization, but also influences the selection of medical institutions.