• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.34 no.3
• /
• pp.268-278
• /
• 2001

To investigate sedimentary facies and environmental changes of the Nakdong River Estuary and its adjacent coastal area, the grain size analysis and measurement of organic matter, calcium carbonate, clay mineral and metallic elements were carried out for forty surface sediment samples. Based on regional distribution pattern and characteristics of the surface sediments, sedimentary facies in the study area can be divided into sand facies (TYPE I), mud facies (TYPE II) and sand-mud mixed facies (TYPE III). TYPE III is the transition of TYPE I and TYPE II in every aspects of sediment characteristics. It suggests that TYPE III may have been formed by the mixture of two different source of sediment : one derived from Nakdong River and the other resuspended fine-grained sediments from the Jinhae Bay by winnowing action during floods or storms. Among many aspects of environmental change after the construction of the Nakdong Barrage, the most significant is the increase of sand content off the sand barrier region. It could be explained by several reasons including decreased input of fine-grained sediment from river, increased hydrodynamic energy level off the sand barrier region and artificial effects such as dredging and dumping.

• Journal of the Ergonomics Society of Korea
• /
• v.35 no.6
• /
• pp.551-568
• /
• 2016

Objective: The objective of this study is to identify the difference in the press behavior characteristics of 3D Touch, which is a new touch interaction of smart phones, and the existing 'Tap and Long Press' touch interaction, and to examine behavior changes upon feedbacks. Background: Since 3D Touch is similar to the existing 'Tap and Long Press' touch interactions in terms of press behavior, which is likely to cause interference, it is necessary to conduct a preliminary study on behavior characteristics of touch interactions. Method: In utilization of smart phones with the 3D Touch function to measure press behavior characteristics of touch interaction, an experiment was conducted where 30 subjects were given a task to press 30 buttons of touch interactions on the screen. During the experiment, two press behavior characteristics-maximum touch pressure and press duration-were analyzed. To grasp changes in behaviors upon feedbacks, the task was carried out in a condition where there was no feedback and in a condition where there were feedbacks of specific critical values. Results: While there was no feedback given, subjects tended to press with much strength (318.98gf, 0.60sec) in the case of 3D Touch, and press the Long Press button for a while (157.12gf, 1.10sec) and press the Tap button with little strength only for a short moment (37.92gf, 0.10sec). 3D Touch and Long Press had an area of intersection in time, but when feedbacks of specific critical values were given, there were behavior calibration effects to adjust the press behavior characteristics of 3D Touch and Long Press. Conclusion: Although interferences are expected between 3D Touch and Long Press due to the similarity of press behaviors, feedbacks induce behavior calibration. Hence, once feedbacks were provided with 3D Touch operated in an appropriate condition of critical pressure, interference between two motions can be minimized. Application: The findings of this study are expected to be utilized as a basis for the values of optimal critical pressure, at which users can easily distinguish 3D Touch from Long Press which is the existing touch interaction.

• Journal of the Ergonomics Society of Korea
• /
• v.35 no.6
• /
• pp.569-580
• /
• 2016

Objective: This study aims to identify the most effective keyboard layout in the area of performance for securing usability in a smart watch-using environment and to verify the usability of touch keyboard calibrated by hand. Background: It is necessary to understand the environmental characteristics in using the smart watch and to secure the usability of touch keyboard based on this understanding in order to take account of the users who use the touch screen in the extreme input conditions caused by the small screen of a smart watch. Method: 30 participants in this study were required to input characters using the QWERTY keyboard and 3x4 keypad (Naratgul, Chunjiin), which were familiar with them, in order to grasp the keyboard layout suitable in the smart watch- using environment; the performance (error rate, performance time) of this case was measured. In addition, 30 participants in this study were required to input the characters setting the QWERTY keyboard with calibrated touch area and the one with uncalibrated touch area, based on the characteristics of touch behavior, by finger typing the keyboard, with the performance (error rate and performance time) of this case measured. Results: QWERTY keyboard (93.3sec) is found to be 31.2% faster than Naratgul keyboard, a kind of 3x4 keypad, and 43.6% faster than Chunjiin keyboard, in the area of efficiency, in the results of the usability evaluation regarding the keyboard layout. QWERTY keyboard with calibrated touch area (7.5%) is found to be 23.5% improved compared to the QWERTY keyboard with uncalibrated touch area (9.8%) in the area of accuracy (error rate). The results of the usability evaluation regarding the QWERTY keyboard with touch area calibrated by finger typing the keyboard and QWERTY keyboard with calibrated touch area (80.7sec) is found to be 5.7% improved compared to QWERTY keyboard with uncalibrated touch area (85.6sec) in the area of efficiency (performance time). Conclusion: QWERTY keyboard is found to have an effective layout in the area of efficiency in the smart watch-using environment, and its improved usability is verified in the areas of accuracy and efficiency in the QWERTY keyboard with a touch area calibrated by finger typing the keyboard. Application: The results of this study may be used to set up the basic touch keyboard of the smart watch. The input usability is expected to secure the smart watch-using environment, which is an extreme input condition by applying QWERTY keyboard with touch area calibrated by finger typing the keyboard.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.16 no.4
• /
• pp.120-140
• /
• 2013

We investigated the occurrence of red tide, harmful algal blooms(HABs), at the end of 14th century until the beginning of 19th century recorded in the Annals of the Joseon Dynasty, which are the authentic and encyclopedic annual records of the Joseon Dynasty of Korea. In total, 81 cases of HABs are recorded in the annals for which authors draw a table and maps. The number of HABs occurrence at each sea is as follows: 68 times at the South Sea; 50 times at the East Sea; and 23 times at the Yellow Sea. A region hit by red tide most frequently was Gyeongsang-do Province (over 80 times), which borders on both the South Sea and the East Sea. HABs written in the annals follow two distinctive occurrence patterns. The first pattern shows red tide started at Gangwon-do Province in March, spread north to Hamgyeongnam-do Province in April, and moved further north to Hamgyeongbuk-do Province in May and June. On the other hand, the second pattern shows red tide occurred in Gyeongsangnam-do Province in August and then expanded north to Gyeongsangbuk-do Province in September. HABs generally happened from March to September, culminating in August. Paralytic shellfish poisoning incidents involving human deaths were reported in Jinhae, Geoje and Tongyeong, occurring February to June. Fish mortality increased throughout Gyeongsang-do Province from July to September. HABs occurred on an extensive scale from 1394 to 1451 and again from 1654 to 1706. HABs also occurred on a lesser scale from 1493 to 1534 and again from 1588 to 1609. In general, vast HABs occurred in odd years (1399, 1403, 1413 and 1681).

• Korean Journal of Community Nutrition
• /
• v.8 no.5
• /
• pp.652-657
• /
• 2003

This study was carried out to investigate the effects of the gender, obesity rate, nutrition knowledge and dietary attitude on the dietary self-efficacy of adolescents. The subjects were 1,022 (518 male, 504 female), aged 13-17 years living in Busan, Masan, Jinju and Jinhae city. This survey was conducted from April 8 to April 22,2002 by questionnaires and data were analyzed by SPSS program. The results are summarized as follows. Nutrition knowledge scores and dietary self-efficacy scores of the females were higher than those of the males. The higher the nutrition knowledge and dietary attitude scores, the higher dietary self-efficacy. Dietary attitude has direct effects on dietary self-efficacy and obesity rate has in-direct effects which was mediated by nutrition knowledge. Gender and nutrition knowledge have direct effects and indirect effects which were mediated by dietary attitude. Dietary attitude showed the greatest total causal effect in relation to dietary self-efficacy.

• Journal of the Korean Geotechnical Society
• /
• v.29 no.5
• /
• pp.39-52
• /
• 2013

The shear stress characteristics of landslide materials can be affected by various factors. We examined the shear stress characteristics of two different soils using ring-shear apparatus, in which saturation-consolidation-shearing speed can be easily controlled. This paper presents (i) shear stress-time characteristics, (ii) shear stress depending on normal stress and shear speed and (iii) shear stress as a function of shearing speed. Materials used in this paper were the Nakdong River sand and muds taken from Jinhae coastal area in Korea. Samples were prepared in three types: Sand (upper)-Sand (lower), Clay (upper)-Clay (lower) and Sand (upper)-Clay (lower). The upper and lower indicate the samples placed in upper and lower ring shear boxes, respectively. For given normal stresses (50 and 100 kPa) and shearing speed (0.1 mm/sec), we performed ring shear tests. Then the failure lines were determined in the second test. Last, we determined the shear stress characteristics depending on different shearing speeds, such as 0.01, 0.1, 1, 10, 100 mm/sec. As a result, we found that shear stress characteristics are strongly dependent on above three factors. The shear stress of Sand (upper)-Clay (lower) is smaller than that of Sand (upper)-Sand (lower), but slightly larger than that of Clay (upper)-Clay (lower). The shear stress is also characterized by grain crushing and wetting process at slip surface.

• Asian Journal of Turfgrass Science
• /
• v.17 no.1
• /
• pp.35-44
• /
• 2003

Popillia quqdriguttata is a serious insect pest in Korean golf courses. The adult feeds on leaves of latifoliate trees and herbaceous plants while the larva feeds on roots of turfgrass. Thus, control of p. quadriguttata adults was tried with registered insecticides in golf courses in Korea. The insecticides used in the experiments were carbaryl + phosalone WP, chlorpyrifos + diflubenzuron WP, chlorpyrifos-methyl EC, deltamethrin EC, etofenprox WP, etofenprox + diazinon WP, etofenprox + tebufenozide EC, fenitrothion EC, imidacloprid SC, pyraclofos WP, and tralomethrin EC. Mortalities of P. quadriguttata were over 95% in carbaryl + phosalone WP, chlorpyrifos + diflubenzuron WP, etofenprox + diazinon WP, and fenitrothion EC at petri dish and in greenhouse. In the field test, corrected mortality of P. quadriguttata was 95.2% and 80.9% in carbaryl 40% +phosalone 20% WP and fenitrothion 50% EC, respectively. Spreading agent enhanced toxic effect of used insecticides to p. quadriguttata adults except carbaryl + phosalon 20% EC. p. quadriguttata adult was firstly observed to feed on leaves of Canna generalis at the Yongwon golf club in Jinhae, Gyeongnam and Prunus ameriaca var. ansu and p. salicina at the Anyang Honest golf club in Gunpo, Cyeonggi. Therefure, host plants off quadriguftata became 29 species of 26 genera in 19 families. Zoysia matreila at the fairway and roughs of Anyang Benest golf club was damaged by p. quadriguttata larvae in Octomber, 2002 and not recovered in April, 2003. Damaged turfgrass became yellowish and wilted and that retarded recovering in the following spring.

• Journal of the Korean Association of Geographic Information Studies
• /
• v.14 no.2
• /
• pp.82-95
• /
• 2011

The objective of this paper is to analyze the GIS-based water cycle system: rainfall, evapotranspiration, surface run-off of Gyeongsanam-do for the effective rainwater management. The rainfall(1999~2008) analyzed by a spatial interpolation method, showed relatively higher amount in Hadong-gun, Sanchung-gun, and Sacheon-gun on the southwest coast than in Changnyeong-gun, Miryang-si, and Changwon-si in the mideast inland. The evapotranspiration was calculated by the three independent variables: air temperature, landuse, and NDVI(normalized difference vegetation index). The analysis showed that Namhae-gun had the highest evapotranspiration of 93.71mm, and Jinhae-si and Changwon-si had the lowest values of 81.78mm and 84.37mm. The surface run-off was analysed by a run-off equation based on the SCS hydrologic soil classification and landuse. The amount of surface run-off showed that Hadong-gun had the highest value, of 90.40mm, and Geochang-gun had the lowest, of 46.69mm. The analysis results of the GIS-based water cycle system will be used to support the establishment of the effective rainwater management plan in Gyeongasngnam-do.

• Journal of the Korean Society of Marine Environment & Safety
• /
• v.19 no.5
• /
• pp.430-438
• /
• 2013

In this study, the seasonal field survey was conducted in Goseong Jaran Bay(22 stations), Geoje Hansan Bay(15 stations) and Jinhae Bay(18 stations). We analyzed the sediment environmental parameters(Chemical Oxygen Demand, Ignition Loss, Acid Volatile Sulfides, Total Organic Carbon) and biotic parameters of macrobenthic polychaetes(number of species, density, diversity, evenness). It had a good correlation between total organic carbon and polychaete diversity(R=0.61, P<0.01), and we made a decision them as representative environmental indices. As a result of that, regarding the criteria in the assessment of farm environment, we suggest concentrations of total organic carbon : Peak Point = 15 mg/g dry, Warning Point = 26 mg/g dry, Contaminated Point = 31 mg/g dry and polychaete diversity : ~2.6(Good), 2.6~2.1(Moderate), 2.1~1.2(Poor) and 1.2~(Bad). This could be a scientific basis to establish the environmental standards for fishery management.

• Journal of the Korean Society for Marine Environment & Energy
• /
• v.7 no.2
• /
• pp.75-81
• /
• 2004

A large amount 2.1×106 ㎥ of the polluted sediment was dredged from the Masan Bay and deposited in Gapo confined area, Masan. The dissolved metal concentrations of seawater in the dumping site (Gapo area) were observed during one tidal cycle and compared with those of seawater obtained from Jinhae Bay. The sediment was evaluated as from Non polluted to Moderately polluted by USEPA standards. It was judged that toxicological effects of sediment analyzed ranged from ERL to ERM with copper and zinc, and ERL with cadmium, chrome, lead, and nickel by the Adverse Biological Effects. The pollutant concentration was low in surface sediment compared to deeper sediment since the sediments with relatively low concentrations of pollutant were dumped to the surface. The pollutant concentration was low in surface sediment compared to deeper sediment since the sediments with relatively low concentrations of pollutant were dumped to the surface. The benthic organisms in Gapo area had higher concentrations of trace metals (Oyster: Zn 238.96, Cu 5.29 ㎍/g wet wt., Clam: Zn 17.71, Cu 1.00 ㎍/g wet wt., Mussel. Zn 187.98, Pb 0.28, Cr 0.15, Mn 4.23, Sr 1.45 and Fe 100.33 ㎍/g wet wt.) compared to outside of dumping site. However, the trace metal level in the bivalves was less than the NFPQIS (National Fisheries Products Quality Inspection Service) standard.