• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.6
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• pp.165-173
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• 2012

Given a connected, weighted, and undirected graph, the Minimum Spanning Tree (MST) should have minimum sum of weights, connected all vertices, and without any cycle taking place. Borůvka Algorithm is firstly suggested as an algorithm to evaluate the MST, but it is not widely used rather than Prim and Kruskal algorithms. Borůvka algorithm selects the Minimum Weight Edge (MWE) from each vertex with distinct weights in $1^{st}$ stage, and selects the MWE from each MSF (Minimum Spanning Forest) in $2^{nd}$ stage. But the cycle check and the number of MSF in $1^{st}$ stage and $2^{nd}$ stage are difficult to implication by computer program even if it is easy to verify visually. This paper suggests the generalized Borůvka Algorithm, This algorithm selects all of the same MWEs for each vertex, then checks the cycle and constructs MSF for ascending sorted MWEs. Kruskal method bring into this process. if the number of MSF greats then 1, this algorithm selects MWE from ascending sorted inter-MSF edges. The generalized Borůvka algorithm is verified its application by being applied to the 7 graphs with the many minimum weights or distinct weight edges for any vertex. As a result, the generalized Borůvka algorithm is less required for cycle verification then the Kruskal algorithm. Therefore, the generalized Borůvka algorithm is more fast to obtain MST then Kruskal algorithm.

• Journal of The Korean Association For Science Education
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• v.25 no.6
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• pp.698-709
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• 2005

When modeling students' conceptual understanding, there are several different frameworks, among which are the alternative conception framework and the mental model framework, which converge to suggest a form of knowledge representation. However, little research has explained how they are different from each other and from memory. The purpose of this study was to develop a new mental model theory that integrates the different terminologies and their background theories, which refer to students' ideas not only in science education, but also in other research areas. For this purpose, at first, we compared different terminologies including alternative conception, p-prim, and mental models, and the underlying theories used for representing students' ideas in learning science. Through such comparison, we tried to find the relationship among them. We reviewed related literature and synthesized the results from both cognitive science (related research areas) and science education approaches, especially, Vosniadou's mental model theory. Based on reviewing previous studies, we have developed a preliminary mental model theory 'an integrated theoretical structure of mental models'. We applied the new mental model theory to interpret data on students' ideas about circular motion from our previous research. We expect our new mental model theory will help us understand how students form their own ideas in science from an integrated perspective.

• Journal of Satellite, Information and Communications
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• v.12 no.2
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• pp.11-14
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• 2017

In this paper, we introduce a method of light focusing effect using prism structure to solve optical discontinuity of conventional external signage LED panels. The prims structures were patterned on a transparent polycarbonate substrate with MEMS and femto-second laser process. We have confirmed that the patterned prism structures on the substrate made artificial LED lights on empty space between the panels by light guide effect of the structure. The artificial light's lateral positions were controlled by thickness of polycarbonate substrate. This cost effective prim patterned transparent film can be utilized on digital signage LED panels to achieve good optical communication.

• Journal of Plant Biology
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• v.27 no.3
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• pp.179-189
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• 1984

Durch vergleichende Untersuchungen von Ribes nigrum L. var. 'Rosenthals Langtraubige Schwarze' zwischen $prim\"{a}rem$ und $sekund\"{a}rem$ Jugendstadium (P.J. und S.J.) eine vertiefte Einsicht in die beiden zeitlich unterschielich langen $Entwicklungsabl\"{a}ufe$ zu bekommen und auf diese Weise bessere Ansatzpunke $f\"{u}r$ die Regulierung der $Bl\"{u}tc-nknospeninduktion$ zu gewinnen, war das Ziel vorliegenden Untersuchungen. Diese Untersuchungen $f\"{u}hrten$ zu den flogenden Ergebnissen: Die Dauer der Jugendphase von Ribes nigrum L. betrug bei den P.J.-Pflanzen ca. 7 Monate, bei den S.J.-Pflanzen ca. 5 Monate. Die $Bl\"{u}hreife$-(Ripeness to flower)-setzte bei den P.J.-Pflanzen erst beim 20. Nodium ein, bei den S.J.-Pflanzen bereits beim 5. Nodium. Das $f\"{u}hrte$ dazu, da${\beta}$ bei gleicher Nodienzahl die P.J.-Pflanzen weniger $Bl\"{u}te-nknospen$ angesetzt hatten als die S.J.-Pflanzen. Die erste $Bl\"{u}tenknospendifferenzierung$ setzte bei den P.J.-Pflanzen in der oberen Triebmitte etwa am 30. Nodium ein, beiden S.J.-Pflanzen bereits in der unteren Tricbmitte etwa am 20. Nodium. Bie den P.J.-Pflanzen waren die untersten 20. Nodien immer steril, $w\"{a}hrend$ bei den S.J.-Pflanzen $h\"{a}uflgsten$ an dem ersten Nodium $\"{u}ber$ der Basis fertil waren. In allen Versuchen hat sich gezeigt, da${\beta}$ der Wachstumsabschlu${\beta}$ -(Bildung einer Terminal Knospe)-, der bei Ribes nigrum L. durch Kurztag eingeleitet wird, bei den P.J.-Pflanzen langsammer als bei den S.J.-Pflanzen erfolgt. Dies $f\"{u}hrt$ dazu, da${\beta}$ die Pflanzen der $sekund\"{a}ren$ Jugendphase auf die photokybernetischen Stimulation empfindlicher reagieren als die der $prim\"{a}ren$ Jugendphase. Alle untersuchten Versuchsdaten $f\"{u}hren$ zu dem Schlu${\beta}$, da${\beta}$ die Wurzelgibberelline $(GA_n)$ keinen Einflu${\beta}$ auf die $Jugendsterilit\"{a}t$ ($Basissterilit\"{a}t$) haben. Aus den Untersuchungen geht hervor, da${\beta}$ die induktive Ma${\beta}$nahme zur Beschleunigung der $Bl\"{u}tenknospenbildung$ $f\"{u}r$ eine $Z\"{u}chtungsselektion$ erst dann eingesetzt werden sollen, wenn die P.J.-Pflanzen mehr als 20 Nodien ausgebildet haben.

• Korean Journal of Pharmacognosy
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• v.39 no.4
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• pp.357-364
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• 2008

The roots of Saposhnikovia divaricata Schischk. (Umbelliferae) have been known to possess analgesic, anti-inflammatory, anti-parasitic and anti-bacterial activities, and used for curing headaches, fever and arthralgia. In this study, we aimed to isolate active constituents to provide phytochemical data for the quality control of this plant. Nine coumarins, eight chromones, three sterols and a coumarolignan were isolated from EtOAc-soluble fraction of the roots of S. divaricata through repetive column chromatography method using silica gel, ODS gel, Sephadex-LH 20, MPLC and HPLC. By analyses of spectroscopic data and comparison of their data with those of published values, the compounds were identified as 3'-O-angeloylhamaudol (1), ${\beta}$-sitosterol (2), marmesin (3), phellopterin (4), anomalin (5), imperatorin (6), xanthotoxin (7), deltoin (8), bergapten (9), stigmasterol (10), ledebouriellol (11), hamaudol (12), 8'-epicleomiscosin A (13), xanthoarnol (14), cimifugin (15), 5-O-methylvisamminol (16), daucosterol (17), 4'-O-${\beta}$-D-glucosyl-5-O-methylvisamminol (18), nodakenin (19), sec-O-glucosylhamaudol (20), prim-O-glucosylcimifugin (21). Among them, 8'-epicleomiscosin (13) was firstly reported from Umbelliferae family and xanthoarnol (14) and nodakenin (19) were isolated from this plant for the first time.

• Koreanishche Zeitschrift fur Deutsche Sprachwissenschaft
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• v.1
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• pp.11-39
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• 1999

Das Ziel dieses Aufsatzes liegt darin, $da\ss$ wir eine Unterlage $f\"{u}r$ die Erarbeitung des kunftigen vergleichenden deutsch-koreanischen Verbvalenzlexikons bereitstellen, indem wir zweisprachige Valenz-lexika vergleichen, bei denen die Muttersprache der Lemenden als Ausgangssprache und die deutsche Sparche als Zielsprache fungieren, und ein neues Valenzmodell mit dem Verb 'kaufen 팔다' aufzeigen. Als Ergebnis dieser Arbeit $k\"{o}nnen$ wir feststellen, $da\ss$ die Entwicklung der kontrastiven Valenzlexikographie vom register-ahnlichen Lexikon hin zum benutzerfreundlichen $W\"{o}rterbuch$ $verl\"{a}uft$. Und ferner ist die Tendenz ansteigend, zweisprachige Versionen aus den einsprachigen $W\"{o}rterb\"{u}chern$ des Deutschen zu entwickeln, denn die kontrastiven $W\"{o}rterb\"{u}cher$ kommen den praktischen $Bed\"{u}rfnissen$ des Fremdsprachenunterrichts $f\"{u}r\;Anf\"{a}nger$ mehr entgegen als die einsprachigen. Die Valenzlexika sollten $prim\"{a}r$ dem Deutsch Lernenden helfen, seinen Wortschatz zu erweitern und korrekte $S\"{a}tze$ zu bilden, sollten jedoch nicht unmittelbares Selbststudienmaterial, sondern Nachschlagewerke sein. Die neuere Entwicklung in der Valenzlexikographie $f\"{u}hrt$ hin zum didaktisch orientierten $W\"{o}rterbuch$, in dem die $Valenzeintr\"{a}ge$ neben anderen syntaktischen und semantischen Informationen stehen. $F\"{u}r$ Studenten im Grundstudium sind $W\"{o}rterb\"{u}cher$ in der Fremdsprache zu schwierig. Bei der zweisprachigen Version erleichtern die $Valenzeintr\"{a}ge$ In der Muttersprache den Studierenden den Umgang mit dem $Lernw\"{o}rterbuch$. In Zukunft $k\"{o}nnen\;Valenzw\"{o}rterb\"{u}cher$ als wichtige Hilfsmittel im Fremd­sprachenunterricht noch an Bedeutung gewinnen. Ein $Valenzw\"{o}rterbuch$ ist vor allem ein $Produktionsw\"{o}rterbuch,\;denn\;es\;enth\"{a}lt$ syntaktisch-semantische Informationen und $Beispiels\"{a}tze$, die bei der Produktion korrekter Strukturen helfen. Das $Valenzw\"{o}rterbuch$ soll ein Nachschlagewerk, ein $Lernw\"{o}rter-buch$ zur weiteren Erforschung der syntaktish-semantischen Eigenschaften der deutschen Verben sein. Diese Untersuchung $\"{u}ber$ zweisprachige Verbvalenzlexika $k\"{o}nnte\;zur\;k\"{u}nfigen$ Erarbeitung des deutsch-koreanischen kontrastiven Verbvalenzlexikons beitragen.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.34 no.10B
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• pp.994-1003
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• 2009

For Automatic Meter Reading System, good topology of check machines, concentrators, and repeaters in client field is important. Steiner Minimum Tree is a minimum cost tree connecting all given nodes with introducing Steiner points. In this paper, an efficient mechanism allocating and connecting check machines, concentrators and repeaters which are essential elements in automatic meter reading system is proposed, which conducts repeated applications of building approximate Minimum Steiner Trees. In the mechanism, input nodes and Steiner points might correspond to check machine, concentrators or repeaters and edges might do to the connections between them. Therefore, through suitable conversions and processes of them, an efficient network for automatic meter reading system with both wired and wireless communication techniques could be constructed. In our experiment, for 1000 input nodes and 200 max connections per node, the proposed mechanism shortened the length of produced network by 19.1% comparing with the length of Minimum Spanning Tree built by Prim's algorithm.

• Journal of Korea Spatial Information System Society
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• v.8 no.1 s.16
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• pp.107-118
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• 2006

In this paper, several network algorithms were tested to find an optimal one for telecommunication network design. Algorithms such as Dijkstra's shortest path algorithm, Ford-Bellman's shortest path algorithm, Prim's minimum spanning tree algorithm, and Kruscal's minimum spanning tree algorithm were reviewed and compared in terms of feasibility and resulted network construction cost. Then an optimal algorithm that is most suitable for telecommunication network design was selected. For more specific and quantitative analysis of the selected algorithm, it was implemented to a real telecommunication network construction site. The analyzed results showed that the suggested design method when compared with the conventional one, reduced the network construction cost considerably. The total network length estimated by the conventional method were 5267 meters while the suggested method resulted in 4807 meters. Thus the new method reduced the total network length by 8.7 percent which is equivalent to 97,469,000 Won of construction cost. Considering the frequent telecommunication network constructions, due to new urban developments in the nation, the economic benefit of the suggested telecommunication network design method will be significant. In addition to the construction cost savings, the suggested telecommunication network design procedure possesses several other economic benefits. Since the design procedure can be standardized and automatized, it can reduce the design cost itself and the skill acquirement periods required for new or inapt design crews. Further, due to the standardized and automatized design procedure, any telecommunication network design results can accessed more objectively.

• Journal of the Korean Institute of Landscape Architecture
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• v.44 no.6
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• pp.84-97
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• 2016

This study was to investigate the user's thermal environments of the children's parks according to pavements and sunscreen types during periods of heat waves. The measurements were conducted at the sand pits, rubber chip pavement, shelters, and green shade ground of the two children's parks located in Jinju, Korea(Chilam: $N\;35^{\circ}11^{\prime}1.4{^{\prime}^{\prim}}$, $E\;128^{\circ}5^{\prime}31.7{^{\prime}^{\prime}}$, elevation 38m, Gaho: $N\;35^{\circ}09^{\prime}56.8{^{\prime}^{\prime}}$, $E\;128^{\circ}6^{\prime}41.1{^{\prime}^{\prime}}$, elevation 24m) over three days during 11-13, August, 2016. The highest ambient air temperatures at the Jinju Meteorological Office during the three measurement days were $35.9{\sim}36.8^{\circ}C$, which corresponded with the extremely hot weather. A series of experiments measured air temperature, relative humidity, wind velocity, black globe temperature, and long-wave and short-wave radiation of the six directions 0.6 m above ground level. The wet bulb globe temperature(WBGT) and the universal thermal climatic index(UTCI) were used to evaluate thermal stress. Surface temperature images of the play equipment were also taken using infrared thermography. Surface temperatures of the play equipment and grounds were used to evaluate burn risk through contact with playground materials. The results showed the following. The maximum air temperatures averaged over 1-hour period for three days were $36.6{\sim}39.4^{\circ}C$. The sun shades reduced those temperatures by up to $2.8^{\circ}C$(green shade) and $1.0^{\circ}C/2.3^{\circ}C$(shelters). The minimum relative humidity values averaged over 1-hour period for three days were 44~50%. The sun shades increased those humidity values by up to 6%(green shade) and 4%/6%(shelters). The risk of heat related illness at the measurement sites of the children's parks were extreme and high in the daytime hours. The maximum WBGT values averaged over a 30-minute period for three days were $31.2{\sim}33.6^{\circ}C$. The sun shades reduced those WBGT values by up to $2.4^{\circ}C$(green shade) and $0.5^{\circ}C/2.1^{\circ}C$(shelters) compared to sandpits, but would not block the risk of heat related illness in the daytime hours. The category of heat stress at the measurement sites of the children's parks were extreme and very strong in the daytime hours. The maximum UTCI values averaged over a 30-minute period for three days were $39.9{\sim}48.1^{\circ}C$. The sun shades reduced those UTCI values by up to $7.8^{\circ}C$(green shade) and $4.1^{\circ}C/8.2^{\circ}C$(shelters) compared to sandpits, but could not lower heat stress category from extreme and very strong to strong and moderate in the daytime hours. According to the burn threshold criteria when skin was in contact with playground materials, the maximum surface temperature of the stainless steels($70.8^{\circ}C$) surpassed three seconds $60^{\circ}C$ threshold for uncoated steel, that of the rubber chip($76.5^{\circ}C$) surpassed five seconds $74^{\circ}C$ threshold for the plastic, that of the plastic slide($68.5^{\circ}C$) and seats($71.0^{\circ}C$) surpassed the one min $60^{\circ}C$ threshold for plastic, respectively. The surface temperatures of shaded play equipment were lower approximately $20^{\circ}C$ than those of play equipment exposed to the sun. Therefore, sun shades can block the risk of burns in daytime hours. Because of the extreme and high risk of heat related illness and extreme and high heat stress at the children's parks during periods of heat waves, parents and administrators must protect children from the use of playgrounds. The risk of burn when contact with play equipments and grounds at the children's parks during periods of heat waves, was very high. The sun shades are essential to block the risk of burn from play equipments and grounds at the children's parks during heat waves.

• Journal of Preventive Medicine and Public Health
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• v.27 no.2 s.46
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• pp.200-216
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• 1994

In present study, the authors investigated the possible effect of coffee consumption on serum cholesterol level in 1017 men between the ages of 40 and 59 years, who were randomly selected from the members of Seoul Cohort Study. Serum total cholesterol data was collected with other serologic indices (e.g. systolic blood pressure, diastolic blood pressure, hight, weight, etc.) through the program of biennial health check-up offered by Korean Medical Insurance Corporation (KMIC). The amount of coffee consumption was assessed by a self-administered questionnaire through mailing. Other confounding factors, such as age, body mass index, cigarette smoking, alcohol consumption, physical activity, and other dietary intake pattern were also determined by the questionnaire. The differences in means of serum total cholesterol in compared to non consumers were $-0.4{\pm}3.56mg/dl$ for those drinking less than 1 cup a day, $-0.6{\pm}3.60mg/dl$ for those drinking 1 cup a day, and $7.1{\pm}3.41mg/dl$ for those drinking more than 2 cups a day. Since smoking interacted the relationship between coffee consumption and serum total choleaterol, we re-analyzed those relationship in smokers and non-smokers separately Other atherogenic behaviors were well correlated with total cholesterol, so we adjusted the mean values of serum total cholesterol through multivariate model selection with age(r=0.12), total cigarette index (cigarette-years; r=0.10), Quetelet's index ($Kg/m^2$, r=0.16), daily calory expenditure (kcal/day, r=0.06), weekly meat and poultry consumption(g/week, r=0.05), weekly fish consumption (g/week, r=0.08), other caffeinated beverage intake (cups/week), and the amount of sugar and prim added to the coffee. Among those variables only age, Quetelet's index, fish consumption, and total cigarette index (in smokers) were remained in the models. After adjustment, the corresponing differences of total cholesterol in smokers were changed to $0.4{\pm}5.24mg/dl,\;-0.5{\pm}4.97mg/dl,\;and\;8.9{\pm}4.78mg/dl$, which were significantly different among themselves (P=0.011). In non-smokers, however, the differences were not statistically significant (P=0.76). Adjusted mean values of systolic blood pressure and diastolic blood pressure were also determined to evaluate the direct effect of coffee to cardiovascular system, but their means were not significantly different by coffee consumption(p=0.18 for SBP, p=0.48 for DBP). Asuming instant coffee in the most popular type of coffee in Korea, the association observed in our study between coffee and serum total cholesterol, especially in smokers, is very interesting finding for the connection between coffee and serum total cholesterol, because only 'boiled coffee' tend to show significant lipid raising effect rather than to other types of coffee, like filtered or espresso, in most of the western countries. We concluded that people who drink coffee more than 2 cups a day have significantly higher serum total cholesterol level than those who never drink coffee, especially in smokers.