• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.36 no.3
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• pp.175-185
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• 2000

This paper described on a basic study to organize fishing vessel control system in order to control efficiently fishing vessel in Korean offshore. It was digitalized ARPA image on the fishing processing of a fleet of purse seiner in conducting fishing operation at Cheju offshore in Korea as a digital camera and then simulated by used VTMS. Futhermore, it was investigated on the application of FVTMS which can control efficiently fishing vessels in fishing ground. The results obtained were as follows ; (1) It was taken 16 minutes and 35 minutes to casting and hauling net in fishing processing respectively. The length of rope pulled by scout boat was 200m, tactical diameter in casting net was 340.8m, turning speed was 6kts as well. (2) The processing of casting and hauling net was moved to SW, NE as results of simulation when the current direction and speed set into NE, 2kts and SW, 2kts respectively. Such as these results suggest that can predict to control the fishing vessel previously with information of fishing ground, fishery and ship's maneuvering, etc. (3) The control range of VTMS radar used in simulation was about 16 miles. Although converting from a radar of the control vessel to another one, it was continuously acquired for the vector and the target data. The optimum control position could be determined by measuring and analyzing to distance and direction between the control vessel and the fleet of fishing vessel. (4) The FVTMS(fishing vessel traffic management services) model was suggested that fishing vessels received fishing conditions and safety navigation information can operate safely and efficiently.

• Journal of Korean Society of Forest Science
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• v.100 no.2
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• pp.154-164
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• 2011

This study was conducted to develop the semi-crawler type mini-forwarder that can be operated comfortable small-scale logging operation in the steep terrain and also used at a variety of operations such as the civil work in erosion control and forest-road. Considering the minimum turning radius and the width of forest operation road, the total length, width and loading capacity of the semi-crawler type mini-forwarder is 5,750 mm, 1,900 mm and $2.5m^{3}$, respectively. The maximum engine power is 96ps at 3600 rpm. Selected hydraulic pumps are consists of two main pumps and two sub-main pumps. Main hydraulic pumps are utilized to running motor of the front wheel and rear crawler. Sub-main pumps are utilized to the actuation parts such as steering, crane, out-rigger and dump cylinder. The transmission was adapted as the HST (Hydro-Static Transmission) system. The driving parts are designed and manufactured as the front wheel type and the rear crawler type. The steering type was manufactured as the ackerman type. Driving control parts type was designed and manufactured as driver's seat type of normal cars. It is also attached on auxiliary equipments such as winch, log grapple and out-rigger. The traveling speed of the semi-crawler type mini-forwarder in forest road was 5.3 km/hr to 7.7 km/hr.

• Journal of Bio-Environment Control
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• v.22 no.4
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• pp.341-348
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• 2013

Maintenance of adequate soil tension or content during the period of crop growth is necessary to support optimum plant growth and yields. A better understanding of soil tension and content for precision irrigation would allow optimal soil water condition to crops and minimize the adverse effects of water stress on crop growth and development. This research reports on a comparison of soil water tension and content variations in differently textured soils over time under drip irrigation using two different water management methods, i.e. pulse time and required water irrigation methods. The pulse time-based irrigation was performed by turning the solenoid valve on and off for preset times to allow the wetting front to disperse in root zone before additional water was applied. The required water estimation method was a new water control logic designed by Rural Development Administration that applies the amount of water required based on a conversion of the measured water tension into water content. The use of the pulse time irrigation method under drip irrigation at a high tension of -20 kPa and high temperatures over $30^{\circ}C$ was not successful at maintaining moisture tensions within an appropriate range of 5 kPa because the preset irrigation times used for water control could not compensate for the change in evapotranspiration during day and night. The response time and pattern of water contents for all of the tested soils measured with capacitance-based sensor probes were faster and more direct than those of water tensions measured with porous and ceramic cup-based tensiometers when water was applied, indicating water content would be a better control variable for automatic irrigation. The required water estimation-based irrigation method provided relatively stable control of moisture tension, even though somewhat lower tension values were obtained as compared to the target tension of -20 kPa, indicating that growers could expect to be effective in controlling low tensions ranging from -10 to -20 kPa with the required water estimation system.

• Horticultural Science & Technology
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• v.29 no.4
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• pp.317-325
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• 2011

This study was conducted to examine the effect of supplemental lighting on the growth and yield of hydroponically grown sweet pepper (Capsicum annuum L. cv. sprit) under low levels of natural light in winter. The plants were treated with natural light only (control), 3-hour supplemental lighting before sunrise, after sunrise and after sunset with high pressure sodium (HPS, 400W). As the result of these three treatments, the supplemental lighting promoted photosynthesis in the low light intensity condition and particularly photosynthesis was more active right after sun rise in the morning, 1.5-$3.0{\mu}molCO_2{\cdot}m^{-2}{\cdot}s^{-1}$ comparing to those of supplemental lighting after sunset, 0.5-$1.5{\mu}molCO_2{\cdot}m^{-2}{\cdot}s^{-1}$. Transpiration rate and stomatal conductance sharply increased with supplemental lighting after sunrise then they decreased again after turning the lights off. Stomatal size was observed $32.2{\mu}m^2$ after supplemental lighting, whereas the size of the natural light was almost closed at $7.7{\mu}m^2$. The average plant height of sweet papper cv. spirit was 185 cm before sunrise, 188 cm after sunrise and 208 cm after sunset with supplemental lighting for 3hours while the control was 171 cm. With supplemental lighting a better number of fruit set per plant was measured 4.3 before and after sunrise, 3.7 after sunset but 2.6 in the control. Interestingly, there were no significant differences in the sugar content ($^{\circ}Brix$) degree between treatment of supplemental lighting, whereas slight differences between seasons were seen. The marketable fruit yield of sweet pepper (cv. spirit) was $116.0kg{\cdot}ha$ with supplemental lighting, whereas the control (natural light only) was $75.8kg{\cdot}ha$. Despite of spending electricity and depreciation cost, the economic analysis showed net income with supplemental lighting after sunrise was 51% higher than control treatment in cv. spirit.

• Journal of Bio-Environment Control
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• v.28 no.4
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• pp.420-428
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• 2019

This study is the heating energy saving test of the high-bed strawberry crown heating system. The system consists of electric hot water boiler, thermal storage tank, circulation pump, crown heating pipe(white low density polyethylene, diameter 16mm) and a temperature control panel. For crown heating, the hot water pipe was installed as close as possible to the crown part after planting the seedlings and the pipe position was fixed with a horticultural fixing pin. In the local heating type, hot water at $20{\sim}23^{\circ}C$ is stored in the themal tank by using an electric hot water boiler, and crown spot is partially heated at the setting temperature of $13{\sim}15^{\circ}C$ by turning on/off the circulation pump using a temperature sensor for controlling the hot water circulation pump which was installed at the very close to crown of strawberry. The treatment of test zone consisted of space heating $4^{\circ}C$ + crown heating(treatment 1), space heating $8^{\circ}C$(control), space heating $6^{\circ}C$ + crown heating(treatment 2). And strawberries were planted in the number of 980 for each treatment. The heating energy consumption was compared between November 8, 2017 and March 30, 2018. Accumulated power consumption is converted to integrated kerosene consumption. The converted kerosene consumption is 1,320L(100%) for space $8^{\circ}C$ heating, 928L(70.3%) for space $4^{\circ}C$ + crown heating, 1,161L($88^{\circ}C$) for space $6^{\circ}C$ + crown heating). It was analyzed that space $4^{\circ}C$ + pipe heating and space $6^{\circ}C$ + crown heating save heating energy of 29.7% and 12% respectively compared to $8^{\circ}C$ space heating(control).

• Korean Journal of Fisheries and Aquatic Sciences
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• v.13 no.1
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• pp.1-13
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• 1980

The purpose of the present study is to find the light intensity which induces maximum gathering rate and to observe the variation of the gathering rate both in daytime and at night by using three species of commercial fishes: filefish, Stephanolepis cirrhifer (Temminck et Schlegel), conger eel, Astroconger myriaster (Brevoort) and crucian carp, Carassius oarassius (Linnaeus). An experimental tank $(360L\times50W\times55Hcm)$ was set up in a dark room. An illumination system was attached to one end of the tank to control horizontal, light intensity. Six artificial light sources were prepared by combination of two light bulbs (5W, 150W) and seven filters. During the experiment water depth was maintained 50 cm level in the tank. The tank was marked into six longitudinal sections each being 60 cm long to observe the distribution of fish. The fish were acclimatized in dark condition for 40 minutes prior to the main experiment. Upon turning on the light, the number of fish .in each section was counted 40 times every 30 seconds, and the gathering rates were obtain from the average number of fish in each section. In filefish the light intensity inducing maximum gathering rate was 0.7 lx(0.5-1.1 lx), and there nab little difference between day and night. Gathering rate varied propotionally to the length of illumination time. In conger eel the light intensities inducing maximum gathering rate were 1.9 lx(1.2-2.9 lx) in daytime and 5.2 lx (3.2-7.7 lx) at night. Thus, there was a considerable difference between day and night, but the gathering rate remained almost unchanged regardless to the length of illumination time. In crucian carp gathering rate did not show a definite pattern hut fluctuated irregularly. The gathering rate, however, was slightly higher at 16.21 lx, and there was little difference between day and night.

• Journal of Korean Library and Information Science Society
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• v.9
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• pp.63-83
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• 1982

Among many open libraries under the rule of the Japanese imperialism, only the railroad library as the character of special library under the control of the Japanese Government General is remarkable for having opened its facilities to outsiders as well as the interior users. This study tries a) To look into what were the colonial background, aim and motive of the establishment of the railroad library under the Japanese rule, b) To analyze its activities and the change of its organization, c) And to find out its vestiges an the effects which it has on our country's library circles. The following are the result: A. The railroad library under the rule of the Japanese imperialism functioned as a public library by the outside book's circulation rather than the interior using. B. The outsiders were qualified to use it only when they got the joint guarantee for the city resident, which means that the o n.0, pportunity of the circulation was not free for the Koreans rather than the Japanese. C. From the aspect of collections, technical books such as natural science, and reference ones tended to be collected, and their whole composition was focused on the materials for the Japan-Korea identification scheme and development of the national spirit as the Japanese empire's subjects. D. In the respect of its organization, all the clerical employees, as well as the chief librarian were composed of the Japanese. Although the Koreans were in principle prohibited from working there, a few of them were employed as guard or servant as the China-Japan War was close to the end. E. The area of the outside book's, circulation service was expanded throughout the whole region along the railroad connecting Pusan with Manchuria. Such a service activity which contained several meanings, was tried by means of culture's books, circuit's books, train's books, hotel's books, mind's development books and reader's reading books etc. F. Such matters as the limitation on book circulating and the quantity of circulation book, the paid circulation and the partial restriction on free circulation mean the wartime system under the rule of the Japanese imperialism and also a n.0, ppeared as a factor of hampering the Koreans from getting accustomed to using library, which has affected them until now. G. The noticeable thing in the service activity is shown in attempting the diversified and positive way of service like free circulation in order to solidify the attitude of the Koreans toward war by organizing mind's development books as well as culture's books with the China-Japan War. H. On the other hand, it can not be passed over that the diversified service activity of the railroad library played a role of bridge in turning of today's library circles of ours to the modernization.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.14 no.2
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• pp.59-65
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• 1981

The purpose of the present study is to find the light intensity which induces maximum gathering rate and to observe the variation of the gathering rate both in daytime and at night by rising two species of commercial fishes: gray rock cod. Sebastes inermis (Cuvier et Valenciennes) and cat shark, Scyliorhinus torazame (Tanaka). An experimental tank $(360L\;{\times}\;50W\;{\times}\;55H\;cm)$ was set up in a dark room. An illumination system was attached to one end of the tank to control horizontal light intensity. Six artificial light sources were prepared by combination of two light bulbs (5W, 150W) and seven filters. During the experiment water depth was maintained 50 cm level in the tank. The tank was marked into six longitudinal sections each being 60 cm long to observe the distribution of fish. The fish were acclimatized in dark condition for 40 minutes prior to the main experiment. Upon turning on the light, the number of fish in each section was counted 40 times every 30 seconds, and the gathering rates were obtain from the average number of fish in each section. The light intensity inducing maximum gathering rate is as follows: gray rock cod: 16.6 lux (10.6-24.5 lux) (day), 0.7 lux (0.5-1.1 lux) (night), cat shark: 1.9 lux (1.2-2.9 lux) (day), 16.6 lux(10.6-24.5lux) (night). Trend of the gathering rate in illumination time revealed different results in two fish species. Gathering rate of gray rock cod did not show any definite pattern but fluctuated irregularly. The gathering rate was some fluctuating at night. However, that of cat shark was almost constant and did not show any distinctive difference between day and night.

• Land and Housing Review
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• v.5 no.3
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• pp.137-149
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• 2014

The authors derived rental housing policy measures that are appropriate for the current conditions of Korean housing supply and demand based on the confirmation of the issues of Korean rental housing system and reviewing implications from review of cases of foreign countries and these measures can be categorized into linkage with the urban regeneration and multi-functional development, acquisition of financial resources, operational management, policy and institutional aspects. For the expansion of supply of rental housing, it is essential to link the rental housing policy with urban regeneration. To pursue regeneration of underdeveloped areas and expansion of supply of rental housing in line with urban regeneration, more development sites should be added. Further, the rental home policy must be integrated into a new paradigm that includes securing commercial viability and providing various residential conveniences through multi-functional development. In addition, diversification of developers of real estates turning away from the existing framework of policy that has been focused only on the state-led housing supply so that local governments and private sector players can take part in. Next, new options for funding the supply of rental housing must be sought. First, raising financial resources sequentially through cyclical development approach could be considered. Or, various funding schemes including utilizing Tax-increment financing (TIF) based on the local tax revenues that will be accrued after the development projects and supply of rental housing. Or there should be various schemes to raise funds including utilization of TIFs that are based on the revenues that will be realized after the development projects and supply of rental housing, or utilizing REITs where funds can be provided through private sector investments. Also, getting out from the planning practice that focused only on physical expansion of supply of rental housing, continual operational management must be performed even after the development. These activities must be supported through establishment of control tower at the national level and continuous attention must be paid even after the development by developing specialized operational management companies that are led by private sector players. Finally, in addition to the hardware support that is focused on the public rental housing only, software support such as conditional provision of housing voucher or tax exemption for low-income classes should be provided, too. In other words, a shift from policies that are supplier-centric to ones that are customer-centric must take place.

• International Journal of Highway Engineering
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• v.11 no.3
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• pp.61-74
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• 2009

Traffic accident risk index Computation model's development apply traffic level of significance about area of road user group, road and street network area, population group etc.. through numerical formula or model by countermeasure to reduce the occurrence rate of traffic accidents. Is real condition that is taking advantage of risk by tangent section through estimation model and by method to choose improvement way to intersection from outside the country, and is utilizing being applied in part business in domestic. However, question is brought in the accuracy being utilizing changing some to take external model in domestic real condition than individual development of model. Therefore, selection intersection estimation element through traffic accidents occurrence present condition, geometry structure, control way, traffic volume, turning traffic volume etc. in 96 intersections in this research, and select final variable through correlation analysis of abstracted estimation elements. Developed intersection design model taking advantage of signal type, numeric of lane, intersection type, analysis of variance techniques through ANOVA analysis of three variables of intersection form with selected variable lastly, in signal crossing through three class intersection, distinction variable choice risk in model, no-signal crossing risk distinction analysis model and so on develop.