• Economic and Environmental Geology
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• v.56 no.2
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• pp.115-123
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• 2023

We introduce a new 'image-mapping' in-situ U-Pb dating method using LA-ICP-MS, proposed by Drost et al. (2018), and show the characteristics and usability of this method through several examples of absolute age results determined by first applying it to samples from the Joseon Supergroup of the Early Paleozoic Era in Korea. Unlike the previous in-situ spot analysis, this in-situ U-Pb dating method for carbonate minerals can determine the absolute age with high reliability by applying the 'image-mapping' method of micro-sized domains based on micro-textural observation, as well as determine the absolute age of multiple geological 'events' that occurred after deposition. This was confirmed in the case of determining the syn-depositional age and the multiple post-depositional ages from carbonate minerals of the Makgol and the Daegi Formations. Therefore, if the 'image-mapping' in-situ U-Pb dating method is applied to determine the absolute age of various types of carbonate minerals that exist in various geological environments throughout the geologic era, it will be possible to secure new geological age information.

• Journal of the Korea Society of Computer and Information
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• v.14 no.3
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• pp.1-11
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• 2009

XQuery query proposed by W3C is one of the standard query languages for XML data and is widely accepted by many applications. Therefore the studies for efficient Processing of XQuery query have become a topic of critical importance recently and the optimization of XQuery query is one of new issues in these studies. However, previous researches just focus on the optimization techniques for a specific XML data management system and these optimization techniques can not be used under the any XML data management systems. Also, some previous researches use predefined XML data structure information such as XML schema or DTD for the optimization. In the real situation, however applications do not all refer to the structure information for XML data. Therefore, this paper analyzes only a XQuery query and optimize by using itself of the XQuery query. In this paper, we propose 3 kinds of optimization method that considers the characteristic of XQuery query. First method removes the redundant expressions described in XQuery query second method replaces the processing order of operation and clause in XQuery query and third method rewrites the XQuery query based on FOR clause. In case of third method, we consider FOR clause because generally FOR clause generates a loop in XQuery query and the loop often rises to execution frequency of redundant operation. Through a performance evaluation, we show that the processing time for rewritten queries is less than for original queries. also each method in our XQuery query optimizer can be used separately because the each method is independent.

• Journal of the Institute of Convergence Signal Processing
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• v.24 no.1
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• pp.27-33
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• 2023

Recently, water shortages have occurred due to climate change, and the need for water management of agricultural water has increased due to the occurrence of algal blooms in reservoirs. Existing algae prevention is operated by putting many people on site and misses the optimal spraying time due to movement through boats. In order to solve this problem, it is necessary to block contamination in advance and move within time to uniformly spray complex microorganisms uniformly. Control drones are used for pesticide spraying and can be applied to algae prevention work by utilizing control drones. In this paper, basic research for the establishment of a marine control system was conducted for application to the reservoir environment, and as one of the results, the characteristics of a drone nozzle, a core technology that can be used for control drones, were calculated. In particular, it was found that the existing agricultural control drones had a disadvantage that the concentration was non-uniform within the suggested spraying interval, and to compensate for this, nozzle positioning and nozzle spraying uniformity were calculated. Based on the experimental results, we develop a core algorithm for establishing an algal bloom monitoring system in the reservoir environment and propose a precision control technology that can be used for marine control work in the future.

• Journal of the Korean Geographical Society
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• v.31 no.2
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• pp.295-308
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• 1996

1. Retrospect of Political Geographic Studies since Liberation, 1945 : 1) Period from 1945 to mid 1960s : There was not political geography as a science in Korea at the time of liberation from Japan 1945. At that time were not pure political geographers in Korea. In 1947, Moon-Hwa Pyo, economics professor, published a book titled Outline of Korean Geopolitics. This book was a first one in the field of political geography and available at that time in the logical descriptions. Bok-Hyon Choi was a first political geographer who in 1959 wrote a book titled Political geography for the collegians of Seoul National University. Professor Choi introduced American-style political geography through the book above mentioned. In 1963, Kie-Joo Hyong published an article titled "Korean Unification: Possibility from the Geopolitical Viewpoint" which was a first article published by Korean young scholar who studied geography in this country. 2) Period from late 1960s to late 1980s : Both Yoon Cha and Duck-Soon Im published frequently several articles of political geography or geopolitics respectively in 1968-1969. And they issued geopolitical disputes on Korean geopolitical structure and an application of rimland theory to Korean peninsula in 1969 through a magazine named Joung-Kyong Younku (the political and economic researches). The disputes played an important role of showing political geography (or geopolitics) to political sciences especially international political Science. Active researches still continued in 1970s. In that atmosphere the first Korean book of political geography written by a post-liberation scholar (Duck-Soon Im) titled Principles of Political Geography was published in 1973. This book was influenced much by American political geography after Second World War. In 1980s, the researches continued more actively. Especially administrative districts, capital cities, and sub-capital cities were frequently studied during this period. 3) Period from late 1980s to Present: Recent Studies : 1985 was a year of much production of articles of political geography. The first Ph.D thesis of political geography published in the same year in our country. And since 1985 produced many M.A. articles. Several categories of esearches of political geography was made in the period from late 1980s to present. Capital cities, Korean unification, administrative districts, urban politics, elections, sub-capital cities, and defense walls were important research categories. Reviewing the researches from 1945 to present. I found eight categories of political geography in Korea: capital cities, administrative districts, geopolitical structure of Korean peninsula, division and unification of Korea, sub-capital cities, defense walls, elections, and urban politics. Each category includes several scholars respectiveiy. 2. Study Tasks and Prospects in Korean Political Geography: In relation to Korean circumstances there are three study-tasks. The first task of Korean people is unification of two Koreas. Political geographers of Korea must al survey titled Survey Methods of Human Geography for collegians. This book was first one on survey part in Korea. The book however, is insufficient in comprehensiveness in aspects too. I think that the important tasks of general-synoptic human geography in Korea are \circled1 publication of comprehensive books of human geography in the aspects and methodologies for collegians and \circled2 acceptance of academic world of human geography in Korea of variety in methodologies of human geography for future progress. progress.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.34 no.2
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• pp.1-15
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• 2016

This study aims at the consideration of the usages of traditional waterscape elements, which are difficult to define their concepts and their differences and it has been proceeded mainly with analysis of literature. It elicited various waterscape types by extracting the place names associated with the watersacpe elements from the chapter "Sancheon" of the volumes Gyeongsang-province in "Sinjeung Donggukyeojiseungram", which is a government-compiled geography book in the early period of Joseon Dynasty, and drew the features of each waterscape element by interpreting the dictionary definition and the original text and studying the similar examples. The results of study are drawn as follows. 1. The chapter "Sancheon" includes 22 types of waterscape elements and they are classified by means of locations and water-flow forms: River Landscape, Lake & Pond Landscape, Coast landscape. 2. River landscape maintaining constant natural water-flow constitutes the linear type, related to the class of stream, which includes 'Su(water)', 'Gang(river)', 'Cheon(stream)' and 'Gye(brook)' and the dotty type, created by the nature of trenched meander rivers, which includes 'Tan(beach)', 'Roe(rapids)', 'Pok(waterfall)' and 'Jeo(sandbank)'. 3. Lake & Pond Landscape forming water collected in a certain area constitutes 'Ho(lake)', which is a broad and calm spot created around mid and down stream of river, 'Yeon(pool)', 'Dam(pond)', 'Chu(small pond)', which are naturally created on the water path around mid and down stream of river, 'Ji(pond)', 'Dang(pond)', 'Taek(swamp)', which is collected on a flatland and 'Cheon(spring)', 'Jeong(spring)' which means gushing out naturally. 4. Coast Landscape includes 'Ryang', 'Hang', which are the space between land and an island or islands, 'Got(headland)' which sticks out from the coast into the sea, 'Jeong(sandbank)' which forms sandy beaches and 'Do' which shows high appearance frequency by reflecting the geographical importance of islands. This study comprehended the diversity of traditional waterscape elements and drew the fact that they are the concept reflecting the differentiated locational, scenic and functional features. That way, it understood the aesthetic sense on nature, which ancestors had formed with the interests in natural landscape and the keen observation on it, became the basic idea elucidating the characteristic on Korean traditional gardens, which minimize the artificiality and make nature the subject.

• Journal of Soil and Groundwater Environment
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• v.10 no.4
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• pp.33-44
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• 2005

On the basis of a stepwise and careful integration of various field and laboratory methods the analysis of groundwater flow characterization was performed with five boreholes (BH-1, -2, -3, -4, -5) on a pilot site of Natural Forest Park in Guemsan-gun, Chungcheongbook-do, Korea. The regional lineaments of NW-SE are primarily developed on the area, which results in the development of many fractures of NW-SE direction around boreholes made in the test site for the study. A series of surface geological survey, core logging, geophysical logging, tomography, tracer tests, and heat-pulse flowmeter logging were carried out to determine fracture characteristics and fracture connectivity between the boreholes. In the result of fracture connectivity analysis BH-1 the injection well has a poor connectivity with BH-2 and BH-3, whereas a good with BH-4 and BH-5. In order to analyse the hydraulic connectivity between BH-1 and BH-5, in particular, a conspicuous groundwater outflux in the depth of 12 m and influx in the depth of 65 m and 70 m, but partly in/outflux occurred in other depths in BH-5 were observed as pumping from BH-1. On the other hand, when pumping from BH-5 the strong outflux in the depths of 17 m and 70 m was occurred. The spatial connectivity between the boreholes was examined in the depth of 15 m, 67 m, and 71 m in BH-1 as well as in the depth of 15 m, 17 m, 22 m, 72 m, and 83 m in BH-5.

• Publications of The Korean Astronomical Society
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• v.36 no.3
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• pp.65-78
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• 2021

Jagyeokru, an automatic striking water clock described in the Sejong Sillok (Veritable Records of King Sejong) is essentially composed of a water quantity control device and a time-signal device, with the former controlling the amount or the flow rate of water and the latter automatically informing the time based on the former. What connects these two parts is a signal generating device or a power transmission device called the 'Jujeon' system, which includes a copper rod on the float and ball-racked scheduled plates. The copper products excavated under Gongpyeong-dong in Seoul include a lot of broken plate pieces and cylinder-like devices. If some plate pieces are put together, a large square plate with circular holes located in a zigzag can be completed, and at the upper right of it is carved 'the first scheduled plate (一箭).' Cylinder-like devices generally 3.8 cm in diameter are able to release a ball, and have a ginkgo leaf-like screen fixed on the inner axis and a bird-shaped hook of which the leg fixes another axis and the beak attaches to the leaf side. The lateral view of this cylinder-like device appears like a trapezoid and mounts an iron ball. The function of releasing a ball agrees with the description of Borugak Pavilion, where Jagyeokru was installed, written by Kim Don (1385 ~ 1440). The other accounts of Borugak Pavilion's and Heumgyeonggak Pavilion's water clocks describe these copper plates and ball releasing devices as the 'Jujeon' system. According to the description of Borugak Pavilion, a square wooden column has copper plates on the left and right sides the same height as the column, and the left copper plate has 12 drilled holes to keep the time of a 12 double-hours. Meanwhile, the right plate has 25 holes which represent seasonal night 5-hours (Kyeong) and their 5-subhours (Jeom), not 12 hours. There are 11 scheduled plates for seasonal night 5-hours made with copper, which are made to be attached or detached as the season. In accordance with Nujutongui (manual for the operation of the yardstick for the clepsydra), the first scheduled plate for the night is used from the winter solstice (冬至) to 2 days after Daehan (大寒), and from 4 days before Soseol (小雪) to a day before the winter solstice. Besides the first scheduled plate, we confirm discovering a third scheduled plate and a sixth scheduled plate among the excavated copper materials based on the spacing between holes. On the other hand, the width of the scheduled plate is different for these artifacts, measured as 144 mm compared to the description of the Borugak Pavilion, which is recorded as 51 mm. From this perspective, they may be the scheduled plates for the Heumgyeonggak Ongru made in 1438 (or 1554) or for the new Fortress Pavilion installed in Changdeokgung palace completed in 1536 (the 31^st year of the reign of King Jungjong) in the early Joseon dynasty. This study presents the concept of the scheduled plates described in the literature, including their new operating mechanism. In addition, a detailed model of 11 scheduled plates is designed from the records and on the excavated relics. It is expected that this study will aid in efforts to restore and reconstruct the automatic water clocks of the early Joseon dynasty.

• Korean Journal of Heritage: History & Science
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• v.51 no.4
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• pp.44-65
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• 2018

This study examined the costumes of the characters in the painting titled Hig yongru Banghwoedo, which was designated as National Treasure No. 1879 in September 2015, and is currently kept in the Dongguk University Museum. The painting depicts a social gathering of Joseon aristocrats held at the higyongru, or watch tower, of the Gwangjumok, a government office, in 1567. It is characterized by the delicate illustration of the government officials, the main characters of the gathering, and the hyangri, ajeon, najang, chorye, akgong, and yeogi, the lower-class employees of the office. In order to investigate the costumes they wore, diverse materials including literature, costume artifacts, and paintings were used as reference sources. The scope of the study was limited to the characters' headdress and gown, and the accessories attached to the former. The study of men's clothing revealed that officials wore a samo and a red dalryeong as basic attire. In addition, it is presumed that they wore a belt indicating their official rank in the hierarchy, and a pair of black shoes. Retired officials wore a heuklip wrapped in horsehair or silk fabric with a red jing-nyeong and a doah. The hyangri wore a heukjukbanglip on their head, as well as a white jing-nyeong and a belted doah. In the Goryeo period, the banglip was a type of official headdress worn by members of the aristocratic elite ranked immediately below the king, but in Joseon it was demoted as the official headgear of the hyangri class, which was confirmed through Higyongru Banghwoedo. The ajeon wore a heuklip on their head, and a white jing-nyeong and a doah at the waist. As a rule, the najang wore a chogun on the head, and a banbieui on cheolrik and chungmokdai, but the najang in Higyongru Banghwoedo are depicted wearing a chogun and a cheolrik without a banbieui. Also, the chorye wore a heuklip wrapped in hemp cloth with a red cheolrik, whereas the akgong wore a somoja and a red cheolrik. Female entertainers, both adults and children, are depicted in the painting as either serving the aristocrats, dancing, or playing a musical instrument, wearing their hair in a voluminous, round, high bun, and dressed in a red daiyo, a hwangjangsam with a straight or reclined collar, and a belt. Notably, the donggi, i.e. young gisaeng, are shown wearing their hair in two short braids, and ddressed in a red gown with a y-shaped collar, or po.

• Journal of Korean Society of Forest Science
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• v.110 no.2
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• pp.165-178
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• 2021

Owing to the lack of consistent research on endangered plant species in Korea, there are insufficient data to preservespecies and expand habitats. This study analyzed the preferred habitat and threats to the survival of Aconitum austrokoreense, found on Baekwun Mountain in Gurye-gun, Gwangyang-si, Jeollanam-do Province, and classified as a level two endangered wild plant by the Ministry of Environment, by investigating major environmental factors such as climate, location, soil, and stand structure. By examining five selected sites inhabited by Aconitum austrokoreense on BaekwunMountain, this study found that the habitat had an altitude of 420 to 675 m above sea level and showed a northeast tendency, spreading over a range of inclination angles between 15° and 37°. The average number of plants across the five sites was 156. Site 4 (550 m) had the highest density of 372 plants, with an average height of 0.6 m. The average soil moisture and relative light intensity were 20.48% and 7.34%, respectively. Layer soil was presumed to be sandy loam, characterized by high sand content and good drainage. The habitat had average soil pH of 5.2, average organic matter of 16.46%, average nitrogen of 0.86%, average available phosphate of 11.86 mg/kg, average electrical conductivity of 0.44 dS/m, and average cation exchange capacity of 37.04 cmolc/kg. The total carbon in soil averaged 10.68%. From the analysis of the vegetation structure of sites inhabited by Aconitum austrokoreense, the dominant populations were Pinus koraiensis and Lindera erythrocarpa in Site 1, Magnolia obovata and Carpinus laxiflora in Site 2, Zelkova serrate and Quercus variabilis in Site 3, Staphylea bumalda and Lindera erythrocarpa in Site 4, and Morus bombycis,Styrax japonicus, and Carpinus laxiflora in Site 5. With most habitats located near trails and sap collection sites of Acer pictum, the species were exposed to artificial damage and interference threats.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.29 no.1
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• pp.28-37
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• 2011

In this study, the series-poem, Bihaedangsasippalyoung(48 poems for beautiful scene of Bihaedang), written by scholars of Jiphyonjeon for Bihaedang garden of Anpyung-Daegun(Prince Anpyung, 1416-1453), was analyzed focusing on scenery lexeme to interpret the meaning of scenery and gardening culture of Sadaebu(noblemen) during the first term of Chosun Dynasty. The study result is as followings. First, the subtitle of Sasippalyoung(48 poems) written by Anpyung-Daegun while he grew Bihaedang garden on the foot of Inwang Mountain showed repetitive nomativity comparing joining of yin and yang, such as life and form of animal and plan, time and space, meaning and symbolism, etc. Among scenery lexemes, 38 are represented plant and flowers, and 8 are represented gardening ornaments and animals. Second, the names of gardens were expressed as Wonrim, Jongje, Imchon(Trees and Ponds), or Hwawon(Flower garden), or also presented as Gongjeong(Empty garden), Manwon(Full garden), Jungjeong(Middle garden), Huwon(Backyard), Wonrak(Inner court), or Byulwon(Seperated garden) depending on density and location. In addition, there were pavilions and ponds, stepping stones and stairs, a pergola, a flat bench, flowerpots, an artificial hill, oddly shaped stones, wells, aviary, flower beds, or hedges. A gardener was called Sahwa(flower keeper), planting and gardening of garden trees were called Jaebae(cultivation), a pond island was called Boogoo(floating hill), and miniature landscapes were called Chukjee(reduced land). Third, willows were planted on the outdoor yard, and plum trees were planted in front of the library, which led to bamboo woods road. Peony, camellia, tree peony and crepe myrtle were planted on the inner court with mossy rocks, small artificial hills, glass rocks, flower pots. There were rectangular ponds, while breeding deer, dove, rooster, and cranes. Fourth, landscape elements were enjoyed as metaphysical symbolic landscape by anthropomorphism, such as (1) gentlemen and loyalty, (2) wealth and prosperity, (3) Taoist hermit and poetical life, (4) reclusion and seclusion, (5) filial piety, virtue, introspection, etc. In other words, the garden presented a variety of gardening culture appreciating meaningful landscape, such as investigation of things, reclusion and seclusion, and building orientation of a fairyland yearning eternal youth and Mureungdowon(Taoist Arcadia) by making a garden blending beautiful flowers and trees, with precious birds and animals. Fifth, there were many landscape appreciation schemes, such as Angkyung(looking-up), Bukyung(looking-down), Jeokyung(looking-under), Chakyung(bringing outer space into inside), Yookyung(flower viewing), Yojeong(walking around the garden enjoying flowers), Hwasaekhyangbyuk(flower gardening), and Garden appreciation enjoying landscape through time and seasons with different inspirations.