• Proceedings of the KIEE Conference
• /
• 2015.07a
• /
• pp.251-252
• /
• 2015

The designed hybrid generation system (HGS) not only consider the voltage condition of grid connection point but also do reactive power support according to the transmission system operator's directions. The PCS operation plan in HGS should be supported by precise transferred quantity expectation about reactive power because the system has large physical areas and also be interconnected with grid through long transmission system. Therefore, the realistic measuring process about transferred reactive power quantity by utilizing HGS is required to consider additional compensation plan. In this paper, an reactive power transferred capability of HGS with expected parameter is analyzed, and imposed to the simulation process that is performed on EMTDC environment. Basically, grid information and system characteristics were utilized with Jeju island in Korea, and the performance analysis is carried out based on the composed layout in ongoing project.

• Fisheries and Aquatic Sciences
• /
• v.19 no.9
• /
• pp.36.1-36.3
• /
• 2016

Balssaxius habereri (Balss, 1903) has been newly reported in Korean waters. This species was previously known from the Pacific coast of northern Japan, Korea Strait, Yellow Sea, and Japanese coast of the East Sea. Specimens were collected from western Jeju Island using otter trawls at depths of 65-85 m. Regarding Korean axiid shrimps, a single species, Boasaxius princeps (Boas, 1880), previously known as Axiopsis princeps in Korea, has been recorded. B. habereri is easily distinguished from B. princeps as it does not have tufts of setae on its body and males do not have the first pleopod. Morphological descriptions and color photos of the specimens are provided.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.27 no.9_10
• /
• pp.1144-1152
• /
• 2003

Kenaf has been cultivated in Jeju Island. After being harvested at 105 DAP(day after planting) and separated from kenaf stalks , decorticated kenaf basts were treated with different concentration/temperature/time combinations in order to do chemical rotting. The following fiber properties were compared; rotting effects, colors, crystallinity, molecular structures, dyeabilities, and non-cellulose contents such as pectins, lignins, & hemicellulose. The best results of chemical rotting were obtained from the specimens treated with low concentration/ low temperature/short time. Their colors were bright yellow. The lumens of specimens diminished with the affect of NaOH. The structures of chemically rotted kenaf fibers were cellulose 1. The degree of crystallinity of chemically retted kenaf fibers were very high. Non-cellulose content, especially hemicellulose, was low in the specimens treated with the high NaOH concentration. Dyeabilities of kenaf fibers were higher among the specimens without the non-cellulose content than those with the non-cellulose content.

• Journal of Environmental Science International
• /
• v.25 no.10
• /
• pp.1389-1396
• /
• 2016

A monitoring system for a field magnetometer was configured with assistance of a Raspberry Pi as a data logger. The suggested geomagnetic system uses a semi-real-time data transmission module. The system consists of two parts: a field-observation part and a data-center part. The field-observation part comprises a Raspberry Pi, magnetometer, LTE router, and power source, while the data center part takes samples at the site. The collected magnetometer data are then sent to the data center through the LTE router. The newly designed monitoring system was deployed and checked in Jeju-do island, and found to operate stably. The suggested system is promising in that it is simple and cost saving, providing at least physical insight and knowledge on the complex natural phenomena.

• Animal Systematics, Evolution and Diversity
• /
• v.31 no.2
• /
• pp.86-94
• /
• 2015

The two zooxanthellate scleractinian corals are newly recorded in Korea: Psammocora albopicta Benzoni, 2006 of the family Psammocoridae and Oulastrea crispata (Lamarck, 1816) of the family Faviidae. These families are also newly recorded in Korea. Specimens were collected from the subtidal zones of Jeju-do Island, Korea by SCUBA diving from 1999 to 2014. Two scleractinians are described based on the morphological characters of skeletal structures. Psammocora albopicta is distinguished by its encrusting cerioid growth form, high density of corallites, small calicular diameter, single styliform columella, and fewer rows of enclosed septa. Oulastrea crispata is characterized by its encrusting plocoid growth form, polygonal calicular shape, irregular paliform lobes, and papillose columella.

• Animal Systematics, Evolution and Diversity
• /
• v.31 no.2
• /
• pp.101-106
• /
• 2015

The Remora brachyptera and R. osteochir, belonging to the family Echeneidae were collected for the first time off Jeju Island, Korea, in July and August 2013 and off Ganggu-myeon, Yeongdeok-gun, Gyeongsangbuk-do in June 2014. Remora brachyptera is characterized by a sucker with 16 pairs of disc laminae and a dorsal fin that originates anterior of the origin of the anal fin. Remora osteochir is characterized by a sucker with 18 pairs of disc laminae and a sucking disc that extends beyond the posterior end of the pectoral fin. New Korean names proposed for the species are "Meo-ri-ppal-pan-i" for R. brachyptera and "Ppyeo-dae-ppal-pan-i" for R. osteochir.

• Animal Systematics, Evolution and Diversity
• /
• v.37 no.4
• /
• pp.358-361
• /
• 2021

The genus Rhopalaea Philippi, 1843 is firstly recorded as a Korean fauna. It is distinct from other genera of Diazonidae in order Aplousobranchia by having solitary individuals or at most two embedded in a common test. Solitary ascidian, Rhopalaea crassa (Herdman, 1880), is also newly reported from Korean waters. Rhopalaea crassa has a club-shaped body, developed thorax, a vertical gut loop and yellow patches in transparent test. Specimens of R. crassa examined in this study were collected from the subtidal zone of Jeju-do Island by scuba diving. In this paper, detailed descriptions and photographs of specimens and living forms of R. crassa are provided.

• Food Science and Industry
• /
• v.53 no.2
• /
• pp.225-234
• /
• 2020

During the Japanese colonial period, Japanese brewing companies established 2 breweries in Korea, and brought in malting barley seeds, began trial cultivation in near Daejeon area and Jeju Island, and cultivated hops in Hyesan, Hamgyeong-do. In 1933, Chosun Brewery Co. Ltd. and Showa-Kirin Brewery Co. were established in Yeongdeungpo by Japan and these 2 breweries became the birthplace of today's Hite Brewery and Oriental Brewery. Oriental Brewery tried to cultivate hops and malting barley in Korea, and once self-sufficient but now hops depend on imports, and production of domestic malting barley is about 5% of demand. Beer was only about 5% of domestic alcohol consumption in the early 1970s, but now occupies more than 50% and became the most popular alcoholic drink in Korea. Recently various beers are imported from the world, and many craft breweries serving variety of beers to consumers, thus Korean enjoy heyday of the beer culture.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.55 no.5
• /
• pp.730-735
• /
• 2022

Two specimens of Chlorophthalmus nigromarginatus Kamohara, 1953 (51.02 mm, 66.04 mm in standard length) belonging to the family Chlorophthalmidae were collected on February 8, 2022 in the eastern Jeju-do Island, Korea using a bottom trawl. The species has the following morphological characteristics: snout length almost the same as orbit diameter, bump absent on predorsal, caudal fin with posterior black margin. C. nigromarginatus is morphologically very similar to C. acutifrons but can be distinguished by caudal fin with black margin (C. acutifrons has no black margin). Molecular analyses showed that our specimens almost matched with C. nigromarginatus according to mtDNA 16S rRNA sequences (99.8%). Therefore, we propose a new Korean name for C. nigromarginatus, "Geom-eun-kko-ri-pa-rang-nun-mae-tung-i".

• Journal of the Korean Geosynthetics Society
• /
• v.22 no.2
• /
• pp.55-61
• /
• 2023

This paper describes the comparative results of measured and predicted values for the horizontal displacement of earth retaining wall based on two field cases, In order to examine the application of lateral earth pressure to the earth retaining wall considering the typical ground characteristics (clinker layer) in Jeju. The prediction of the lateral earth pressure causing the horizontal displacement of the retaining wall was performed by elasto-plastic analysis using Rankine earth pressure, Terzaghi & Peck modified lateral earth pressure, and Tschebotarioff lateral earth pressure. As a result, it was confirmed that the maximum horizontal displacement predicted at site A was about 5 times larger than the measured value, and the ground with maximum horizontal displacement occurred by the prediction was found to be the clinker layer. In the case of site B, the predicted value was 4 to 7 times larger than the measured value. In addition, the ground with maximum horizontal displacement and the tendency of horizontal displacement were very different depending on the prediction method. This means that research on lateral earth pressure that can consider regional characteristics needs to be continued, because it is due to the multi-layered ground characteristics of the Jeju area in which bedrock layers and clinker layers are alternately distributed,