• Journal of Biomedical Engineering Research
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• v.23 no.1
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• pp.49-60
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• 2002

Receive dynamic focusing with an array transducer can provide near optimum resolution only in the vicinity of transmit focal depth. A customary method to increase the depth of field is to combine several beams with different focal depths, with an accompanying decrease in the frame rate. In this Paper. we Present a simultaneous multiple transmit focusing method in which chirp signals focused at different depths are transmitted at the same time. These chirp signals are mutually orthogonal in a sense that the autocorrelation function of each signal has a narrow mainlobe width and low sidelobe levels. and the crossorelation function of any Pair of the signals has values smaller than the sidelobe levels of each autocorrelation function. This means that each chirp signal can be separated from the combined received signals and compressed into a short pulse. which is then individually focused on a separate receive beamformer. Next. the individually focused beams are combined to form a frame of image. Theoretically, any two chirp signals defined over two nonoverlapped frequency bands are mutually orthogonal In the present work. however, a tractional overlap of adjacent frequency bands is permitted to design more chirp signals within a given transducer bandwidth. The elevation of the rosscorrelation values due to the frequency overlap could be reduced by alternating the direction of frequency sweep of the adjacent chirp signals We also observe that the Proposed method provides better images when the low frequency chirp is focused at a near Point and the high frequency chirp at a far point along the depth. better lateral resolution is obtained at the far field with reasonable SNR due to the SNR gain in Pulse compression Imaging .

• Atmosphere
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• v.28 no.3
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• pp.305-315
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• 2018

This study investigates the characteristic spatial patterns and dynamic processes associated with the summertime extreme temperature events in South Korea during the last 20 years (1995~2014) using Self-Organizing Map (SOM). The classified SOM patterns commonly have high temperature and anticyclonic circulation anomalies over South Korea. The two major teleconnection patterns are identified: one is from the subtropical western North Pacific (WNP) affecting to the north and the other is from the North Atlantic (NA) affecting downstream region. The meridional teleconnection pattern is related to the forcing of positive sea surface temperature (SST) anomaly over the WNP. The northward propagating Rossby wave generates the East Asia-Pacific (EAP) pattern to form an anticyclonic circulation anomaly over South Korea. On the other hand, NA SST anomalies generate an eastward Rossby wave train across the Eurasian continent, leading to the development of an anticyclonic circulation anomaly over South Korea. The EAP pattern occurs more frequently in July and August, whereas the midlatitude teleconnection pattern associated with NA SST anomalies develops more frequently in early summer (June).

• Journal of Korea Port Economic Association
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• v.32 no.4
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• pp.149-163
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• 2016

Seafarers are an essential resource in maritime industries, which provide navigation skills, vessel maneuvering skills and fishing skills in the fishery industry. They also work as a driving force in pilotage, port operation, vessel traffic service, and marine safety. Other areas in maritime services, which rely on seafarer include safety management of ships, supervisory activities, and maritime accident assessment. In these ways, Korean seafarers have contributed to the growth of Korean economy. However, there have been issues of high separation rate, shortage of supply, multi-nationality, multiplicity of culture caused by employment of foreign seafarers, and aging. The present paper finds that maritime officers and fishery officers demonstrate differences in the statistics of on-board job taking and separation: the separation rate of fishery officers is higher than that of maritime officers. The existing data and statistics by the Korea Seafarer's Welfare & Employment Center could be improved by changing its structure from time series to panel data. The Korea Seafarer's Welfare & Employment Center is the ideal institution for collecting the panel data, as it has already accumulated and published relevant statistics regarding seafarer. The basic design method of the panel data is to adopt and improve it by including the information on ratings of maritime and fishery industries, ranks in a ship, personal information, family life, and career goal. Panel data are useful in short- and long-term forecasts of supply of Korean seafarers; demand evaluation of education, training, and reeducation of the seafarers; demographical dynamic analysis on Korean seafarers; inducement policy of long-term on board job taking in harmony with man-power demands in marine industries such as pilotage service; implementation of job attractiveness policy on Korean seafarers; and employment stabilization of Korean seafarers.

• Journal of Intelligence and Information Systems
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• v.19 no.4
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• pp.81-96
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• 2013

Video information retrieval has become a very important issue because of the explosive increase in video data from Web content development. Meanwhile, content-based video analysis using visual features has been the main source for video information retrieval and browsing. Content in video can be represented with content-based analysis techniques, which can extract various features from audio-visual data such as frames, shots, colors, texture, or shape. Moreover, similarity between videos can be measured through content-based analysis. However, a movie that is one of typical types of video data is organized by story as well as audio-visual data. This causes a semantic gap between significant information recognized by people and information resulting from content-based analysis, when content-based video analysis using only audio-visual data of low level is applied to information retrieval of movie. The reason for this semantic gap is that the story line for a movie is high level information, with relationships in the content that changes as the movie progresses. Information retrieval related to the story line of a movie cannot be executed by only content-based analysis techniques. A formal model is needed, which can determine relationships among movie contents, or track meaning changes, in order to accurately retrieve the story information. Recently, story-based video analysis techniques have emerged using a social network concept for story information retrieval. These approaches represent a story by using the relationships between characters in a movie, but these approaches have problems. First, they do not express dynamic changes in relationships between characters according to story development. Second, they miss profound information, such as emotions indicating the identities and psychological states of the characters. Emotion is essential to understanding a character's motivation, conflict, and resolution. Third, they do not take account of events and background that contribute to the story. As a result, this paper reviews the importance and weaknesses of previous video analysis methods ranging from content-based approaches to story analysis based on social network. Also, we suggest necessary elements, such as character, background, and events, based on narrative structures introduced in the literature. We extract characters' emotional words from the script of the movie Pretty Woman by using the hierarchical attribute of WordNet, which is an extensive English thesaurus. WordNet offers relationships between words (e.g., synonyms, hypernyms, hyponyms, antonyms). We present a method to visualize the emotional pattern of a character over time. Second, a character's inner nature must be predetermined in order to model a character arc that can depict the character's growth and development. To this end, we analyze the amount of the character's dialogue in the script and track the character's inner nature using social network concepts, such as in-degree (incoming links) and out-degree (outgoing links). Additionally, we propose a method that can track a character's inner nature by tracing indices such as degree, in-degree, and out-degree of the character network in a movie through its progression. Finally, the spatial background where characters meet and where events take place is an important element in the story. We take advantage of the movie script to extracting significant spatial background and suggest a scene map describing spatial arrangements and distances in the movie. Important places where main characters first meet or where they stay during long periods of time can be extracted through this scene map. In view of the aforementioned three elements (character, event, background), we extract a variety of information related to the story and evaluate the performance of the proposed method. We can track story information extracted over time and detect a change in the character's emotion or inner nature, spatial movement, and conflicts and resolutions in the story.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.27 no.7
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• pp.380-394
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• 2015

This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2014. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of heat and mass transfer, cooling and heating, and air-conditioning, the flow inside building rooms, and smoke control on fire. Research issues dealing with duct and pipe were reduced, but flows inside building rooms, and smoke controls were newly added in thermal and fluid engineering research area. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results for thermal contact resistance measurement of metal interface, a fan coil with an oval-type heat exchanger, fouling characteristics of plate heat exchangers, effect of rib pitch in a two wall divergent channel, semi-empirical analysis in vertical mesoscale tubes, an integrated drying machine, microscale surface wrinkles, brazed plate heat exchangers, numerical analysis in printed circuit heat exchanger. In the area of pool boiling and condensing, non-uniform air flow, PCM applied thermal storage wall system, a new wavy cylindrical shape capsule, and HFC32/HFC152a mixtures on enhanced tubes, were actively studied. In the area of industrial heat exchangers, researches on solar water storage tank, effective design on the inserting part of refrigerator door gasket, impact of different boundary conditions in generating g-function, various construction of SCW type ground heat exchanger and a heat pump for closed cooling water heat recovery were performed. (3) In the field of refrigeration, various studies were carried out in the categories of refrigeration cycle, alternative refrigeration and modelling and controls including energy recoveries from industrial boilers and vehicles, improvement of dehumidification systems, novel defrost systems, fault diagnosis and optimum controls for heat pump systems. It is particularly notable that a substantial number of studies were dedicated for the development of air-conditioning and power recovery systems for electric vehicles in this year. (4) In building mechanical system research fields, seventeen studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, and renewable energies, piping in the buildings. Proposed designs, performance performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the evaluation of work noise in tunnel construction and the simulation and development of a light-shelf system. The subjects of building energy were worked on the energy saving of office building applied with window blind and phase change material(PCM), a method of existing building energy simulation using energy audit data, the estimation of thermal consumption unit of apartment building and its case studies, dynamic window performance, a writing method of energy consumption report and energy estimation of apartment building using district heating system. The remained studies were related to the improvement of architectural engineering education system for plant engineering industry, estimating cooling and heating degree days for variable base temperature, a prediction method of underground temperature, the comfort control algorithm of car air conditioner, the smoke control performance evaluation of high-rise building, evaluation of thermal energy systems of bio safety laboratory and a development of measuring device of solar heat gain coefficient of fenestration system.

• Journal of Environmental Policy
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• v.7 no.4
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• pp.35-55
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• 2008

Assessing vulnerability to climate change is the first step to take when setting up appropriate adaptation strategies. Adaptive capacity to climate change is the important factor comprising vulnerability. An adaptive capacity index in agricultural water management system was developed considering agricultural water supply and demand for rice production in Jeolla-do, Korea. The agricultural water supply was assumed to be equal to the amount of water stored in the major agricultural reservoirs, while data on the agricultural water demand was obtained from the dynamic simulation results by Korea Agriculture Corporation(KAC). The spatial unit for analysis was conducted at the county(Si, Gun, Gu) level and temporal scale was based on every month from 1991-2003. Adaptive capacity for drought stress index(ACDS index) was calculated as the percentage of data points where the irrigated water supply was greater than the crop water demand. The ACDS index was compared with SWSCI(Standard Water Storage Capacity Index) and the relationship showed high degree of fit($R^2$=0.84) using the exponential function, indicating that the developed ACDS index is useful for evaluating the status of the balance between agricultural water supply and demand, especially for the small sized agricultural reservoirs. This study provided the methodological basis for developing climate change vulnerability index in agricultural water system which is projected to be more frequently exposed to drought condition in the future due to climate change. Further research should be extended to the study on the water demand of the crops other than rice and to the projection of the change in ACDS index in the future.

• The Korean Journal of Nuclear Medicine
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• v.34 no.5
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• pp.410-417
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• 2000

Purpose: Idoxifene is currently entering phase II clinical trials for the treatment of advanced breast cancer. The radiolabeled idoxifene using $[^{123}I]$ provides an opportunity for clinical pharmacology with single photon emission computed tomography (SPECT). The purpose of this study was to prepare radiolabeled idoxifene using $[^{123}I]$ and to determine its cell uptake of breast cancer cell line. Materials and Methods: With a view to evaluating new anticancer drugs, we are investigating the novel antiestrogen pyrrolidino-4-iodotamoxifen (idoxifene). $[^{123}I]$Idoxifene has been prepared in no-carrier-added form using a tributyl stannylated precursor which has been synthesized by means of (2-chloroethoxy)benzene with (${\pm}$)-2-phenylbutanoic acid on the basis of previously reported standard methods. The biodistribution and dynamic behavior of the compound were investigated using the comparative breast cancer cell line, MCF-7 (estrogen receptor-positive) and MDA-MB-468 (non-estrogen receptor). Results and Conclusion: Acylation of (2-chloroethoxy)benzene with (${\pm}$)-2-phenylbutanoic acid gave the versatile ketone (81%) which reacted with 1,4-diiodobenzene to give triphenylethylene as a mixture of E and Z geometric isomers, which were separated by the recrystallization in ethanol. The E-isomer was treated with pyrrolidine to give idoxifene (67%). In order to incorporate radioactive iodine into the 4-position, the 4-stannylated precursor was prepared (30%). The yield of radioiodination was 90-92% with a high radiochemical purity greater than 98%. The ratio of tumor uptake of the breast cancer cell line between MCF-7 and MDA-MB-468 was about 1.7.

• The Korean Journal of Malacology
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• v.22 no.1 s.35
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• pp.27-38
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• 2006

We investigated the reproductive cycle with gonad developmental phases of Solen grandis by histological observations. Seasonal changes in biochemical components of the adductor muscle, visceral mass, foot muscle and mantle were studied by biochemical analysis, from January to December, 2005. The reproductive cycle of this species can be classified into five successive stages: early active stage (December to January), late active stage (January to March), ripe stage (March to July), partially spawned stage (June to July) and spent/inactive stage (July to December). Total protein content was the highest in the foot muscle, the content was high in January (early active stage), the lowest in April (ripe stage), and was the highest in August (partially spawned stage). In the visceral mass, total protein content began to increase in February (late active stage) and reached a maximum in March (ripe stage). Thereafter, it gradually decreased between June and July (partially spawned stage). There was a strong negative correlation in total protein contents between visceral mass and mantle (r = -0.594, p = 0.042). Meanwhile there was a positive correlation between the adductor muscle and foot muscle, the correlation was not statistically significant (r = 0.507, p = 0.093). Total lipid content was the highest in the visceral mass; it was more than 2 to 5-fold higher than that in the adductor muscle, foot muscle, and mantle. Monthly changes in total lipid content were also most dynamic in the visceral mass. It was relatively higher between January and February, showed a maximum in March (the ripe stage), decreased rapidly from April to July (ripe and partially spawned stage), and gradually decreased from September to December (spent/inactive stage). There was a strong positive correlation in total lipid content between foot muscle and adductor muscle (r = 0.639, p = 0.025). Tthough a negative correlation was found between visceral mass and mantle (r = -0.392), the correlation was not statistically significant (p = 0.208). Glycogen contents changed within relatively narrow range and were similar among different tissues. There was no statistically significant correlation in glycogen contents among tissues.

• Korean Journal of Environment and Ecology
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• v.36 no.4
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• pp.361-367
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• 2022

This study was conducted to identify annual variation of observation and activity pattern of Korean chipmunk (Tamias sibiricus) using camera traps in the Seoraksan and Jirisan National Parks, South Korea from May 2019 to May 2021. The annual variation was identified based on the observed frequency through weekly observations. Daily activity patterns of the species were also analyzed by season. The daily activity pattern of chipmunk appeared to be constantly diurnal across the years regardless of habitat or season. The Korean chipmunks living in the two different regions were observed in different time periods throughout the year. While the chipmunks inhabiting the Seoraksan were observed from 18^th to 45^th week, the chipmunks inhabiting the Jirisan National Park were observed from 7^th to 48^th week. This may be influenced by the hibernation period of chipmunks in the two different regions. In both regions, chipmunks were most frequently observed in autumn. It is considered that seasonal variation on population dynamic and activity patterns of chipmunks were reflected in the observation frequency. Although the observation frequency of camera trap is an indirect indicator and thus having a limitation that it cannot distinguish the population density and amount of activity for the target species, camera trapping is still an effective survey technique for monitoring mammals due to its high accessibility and easy use.

• Journal of Service Research and Studies
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• v.12 no.2
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• pp.135-151
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• 2022

This study was conducted on a servicism basis as a study to build the management wisdom of Korea as an asset of human society. The case of the founding and development of the Republic of Korea, which developed into one of the world's leading powers with unprecedented rapid growth despite the devastating three-year war immediately after its founding, is an important subject of study. This study conducted a macroscopic analysis. In the process of carrying out the founding activities, it was confirmed that the original idea inherent in Koreans was the Taegeuk idea of the National Flag. The founders of the Republic of Korea consciously or unconsciously adopted the Taegeuk ideology as the founding ideology. It can be said that the Taegeuk ideology has led to greater success because it is based on the service philosophy, which is the common truth of mankind. In this study, the process of preparing for the founding of the Republic of Korea, which was founded by accepting a new maritime civilization from a country with a long continental civilization, the process of national foundation, and the process of operating the country after its founding were analyzed as a whole. In particular, it discovered the excellent wisdom of the founders who appropriately utilized the strengths of continental and maritime civilizations in necessary situations, and confirmed that the dynamic operating model of development through fierce competition between the two opponents was a success factor for high-speed national development. It requires great wisdom for Koreans with diverse ideological backgrounds and unique personalities to unite to establish and run a nation. This is because fierce competition and cooperation must be carried out at the same time. The great wisdom of the founding of the Republic of Korea was able to be demonstrated because the Taegeuk ideology was acting as a common basic ideology for Koreans. Taegeuk ideology, the source of wisdom that Korea has developed under constant tension, can be capitalized as human wisdom, and additional case studies are needed.