• The Journal of the Acoustical Society of Korea
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• v.28 no.8
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• pp.697-705
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• 2009

An unsupervised (blind) method is proposed aiming at extracting rhythmic sources from commercial polyphonic music whose number of channels is limited to one. Commercial music signals are not usually provided with more than two channels while they often contain multiple instruments including singing voice. Therefore, instead of using conventional modeling of mixing environments or statistical characteristics, we should introduce other source-specific characteristics for separating or extracting sources in the under determined environments. In this paper, we concentrate on extracting rhythmic sources from the mixture with the other harmonic sources. An extension of nonnegative matrix factorization (NMF), which is called nonnegative matrix partial co-factorization (NMPCF), is used to analyze multiple relationships between spectral and temporal properties in the given input matrices. Moreover, temporal repeatability of the rhythmic sound sources is implicated as a common rhythmic property among segments of an input mixture signal. The proposed method shows acceptable, but not superior separation quality to referred prior knowledge-based drum source separation systems, but it has better applicability due to its blind manner in separation, for example, when there is no prior information or the target rhythmic source is irregular.

• The Journal of the Acoustical Society of Korea
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• v.43 no.3
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• pp.351-360
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• 2024

With the increasing use of drone technology, the Unmanned Aerial Vehicle (UAV) is now being utilized in various fields. However, this increased use of drones has resulted in various issues. Due to its small size, the drone is difficult to detect with radar or optical equipment, so acoustical tracking methods have been recently applied. In this paper, a method of localization of multiple drones using the acoustic characteristics of the quadcopter drone is suggested. Because the acoustic characteristics induced by each rotor are differentiated depending on the type of drone and its movement state, the sound source of the drone can be reconstructed by spatially clustering the results of the estimated positions of the blade passing frequency and its harmonic sound source. The reconstructed sound sources are utilized to finally determine the location of multiple-drone sound sources by applying the source localization algorithm. An experiment is conducted to analyze the acoustic characteristics of the test quadcopter drones, and the simulations for three different types of drones are conducted to localize the multiple drones based on the measured acoustic signals. The test result shows that the location of multiple drones can be estimated by utilizing the acoustic characteristics of the drone. Also, one can see that the clarity of the separated drone sound source and the source localization algorithm affect the accuracy of the localization for multiple-drone sound sources.

• Journal of the Korean Institute of Landscape Architecture
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• v.37 no.4
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• pp.72-85
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• 2009

This study attempts to examine the principles of landscape composition for a 'Suhwon(書院)' and the meaning and value of its traditional landscape architecture, in order to apply the results to the design of modern landscape architecture. A 'Suhwon' is a vital space containing the form and meaning of human activity. This study analyzes the characteristics of landscape composition in the construction of the Namgea Suhwon, located in Hamyang, by examining the form and meaning of its area and composition. The Namgea Suhwon was constructed with a suitable configuration and harmony in a good location, neither field nor mountain, and which encompasses transcendence and a return after passage through a period of birth and abundance. Its appearance means 'life existence and hidden death(生居死幽)'. Its spatial system is a reflection of the idea of Samshinoje(三神五帝: The three abilities of Providence and its five subjects) connected with Ilsangje -Samshin -Ohje. It was built based on the idea of Biryebudong(非禮不動) meaning that one should follow only good decorum and avoid discourtesy, complying with "the frame of decorum" developed by the family rites of Chu Hsi. The environmental design of the Namgea Suhwon was interrupted by the material confrontation between mountains and water and a binary code system, such as front to rear, length to breadth, and movement to stillness. The design did not adhere to stiff axes, but pursued the harmonic principles of asymmetric balance in the building and the yard, which are very naturalistic. The name 'Namgea Suhwon' is closely related with the view of placement(置) and harmony(和), which are unified with the function and meaning formed by connecting Sung Confucianism with the Pungsu-Sasinsa structure in the layout of the grounds. When examining the D/H ratio of the building and yard, it can be seen that the spaces of Ganghak, Yusang and Jehyang were built appropriately, according to the natural characteristics of each space, such as a sense of openness, enclosure, tension, relief, enhancement, and hierarchical order. The spaces also reflect human scale concepts that take advantage of auditory features. The transition process after the construction of 'Namgea Suhwon' reveals the intentions of the builder to create an ecological landscape composition based on Placement and Harmony. Placement embodies' a purposeful space in which nature and the building are connected naturally, 'incomplete open space pursuing completion', and 'potential beauty in which tension and relaxation are repeated'. Harmony embodies 'order and continuity having a sense of unity with the natural environment' and the 'sharing of daily life and memory'. 'Namgea Suhwon' contains many ideas for landscape planning, land use and the design of a campus environment.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.21 no.6
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• pp.670-680
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• 2010

A low power single-chip CMOS receiver for 60 GHz mobile application are proposed in this paper. The single-chip receiver consists of a 4-stage current re-use LNA with under 4 dB NF, Cgs compensating resistive mixer with -9.4 dB conversion gain, Ka-band low phase noise VCO with -113 dBc/Hz phase noise at 1 MHz offset from 26.89 GHz, high-suppression frequency doubler with -0.45 dB conversion gain, and 2-stage current re-use drive amplifier. The size of the fabricated receiver using a standard 0.13 ${\mu}m$ CMOS technology is 2.67 mm$\times$0.75 mm including probing pads. An RF bandwidth is 6.2 GHz, from 55 to 61.2 GHz and an LO tuning range is 7.14 GHz, from 48.45 GHz to 55.59 GHz. The If bandwidth is 5.25 GHz(4.75~10 GHz) The conversion gain and input P1 dB are -9.5 dB and -12.5 dBm, respectively, at RF frequency of 59 GHz. The proposed single-chip receiver describes very good noise performances and linearity with very low DC power consumption of only 21.9 mW.

• The Korean Journal of Nuclear Medicine
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• v.37 no.6
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• pp.355-363
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• 2003

Purpose: Regional contractility can be calculated using the regional volume change of left ventricle measured by gated myocardial SPECT image and curve of central artery pressure obtained from radial artery pressure data. In this study, a program to obtain the regional contractility was developed, and reproducibility of regional contractility measurement was assessed. Materials and Methods: Seven patients(male:female=5:2, $58{\pm}11.9$ years) with coronary artery diseases underwent gated Tc-99m MIBI myocardial SPECT twice without delay between two scans. Regional volume change of left ventricle was estimated using CSA (Cardiac SPECT Analyzer) software developed in this study. Regional contractility was iteratively estimated from the time-elastance curve obtained using the time-pressure curve and regional time-volume curve. Reproducibility of regional contractility measurement assessed by comparing the contractility values measured twice from the same SPECT data and by comparing those measured from the pair of SPECT data obtained from a same patient. Results: Measured regional contractility was $3.36{\pm}3.38{mm}Hg/mL$ using 15-segment model, $3.16{\pm}2.25{mm}Hg/mL$ using 7-segment model, and $3.11{\pm}2.57{mm}Hg/mL$ using 5-segment model. The harmonic average of regional contractility value was almost identical to the global contractility. Correlation coefficient of regional contractility values measured twice from the same data was greater than 0.97 for all models, and two standard deviations of contractility difference on Bland Altman plot were 1.5%, 1.0%, and 0.9% for 15-, 7-, and 5-segment models, respectively. Correlation coefficient of regional contractility values measured from the pair of SPECT data obtained from a same patient was greater than 0.95 for all models, and two standard deviations on Bland Altman plot were 2.2%, 1.0%, and 1.2%. Conclusion: Regional contractility of left ventricle measured using developed software in this study was reproducible. Regional contractility of left ventricle will be a new useful index for myocardial function after analysis of the clinical data.

• The Korean Journal of Elementary Counseling
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• v.5 no.1
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• pp.227-253
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• 2006

It seems common for students living at a small county and islands to experience psychological conflicts and be unaccustomed in the peer society because they are not familiar with peer interaction and social skills. This is a case study of L (hereinafter called L) who was grown up in the sheltered school at a small county. L was psychologically disturbed because he couldn't get along well in the transferred school. It is the reason why he had lived in the sheltered school at a small county, so he had not enough exposure to interact with peer and social skills. Sometimes he was obstinate irrationally and when he had trouble with friends, he threw something out or went out of school and tricked juniors dangerously. The fact of disperse with families, parent's indifference, and hate of older brother made L to have ill feeling against family. He had low motivation and low self confident in learning because of short attention time and accumulated poor learning progress. In this study, he was evaluated at various area, such as, intelligent, affective, personal and inter-personal, before counselling. To evaluated the effect of the counselling, K-WISC-III, KPRC, sentence filling test, social adaptation ability test, etc, were administered right after the counselling was over and 8 weeks later. For specific information gathering and analysing, observation diary and deepen counselling were accomplished by homeroom teacher, his mother, and his peers. To correct his problematic behaviors, 13 counseling sessions were accomplished for 6 months and those counselling sessions were recorded and analysed definitely. Followings are the result of this case study. First, he was recovered from the anxiety of inter-personal interaction and he started to interact with peers. The result of sac scale score of KPRC profile was lower than before as much as average student after counseling and 8 weeks later. This reveals that the distress against interpersonal relation have settled. Especially, through the result of sentence filing test, he seemed to feel attachment to peers and be positive, active in the relation of peer. For instance, he was active in the open class lesson and interacted well with peers. It could be said that he overcame the psychological distress comparing with previous time. Second, he could apologize to his peer and juniors for his fault. His attitude were well shown in the letter from an old friend at the sheltered school, average KPRC profiling score comparing with previous counseling time, and remarkable decrease of attack scale score of teacher and peer. Third, his view toward family turn out positive. He recognized his situation that he lived apart from family and even worried about his parent's financial difficulty. Through solving the confliction with his older brother, he could acquire the feeling of family reunion. Fourth, his learning motivation and self-confidence were increased. He confirmed his future positively and he might be judged more attentive because his intelligence index was higher than before as much as average student. With the main goal of this study, verification for effectiveness of counseling. understanding and helping problematic students such as L who lives at a small county and island through investigation of their real situation and problems with the method of counseling and socio-cultural analysis is worthwhile. Identification of ideal relationship with peer is related with positive self-conception, harmonic social adaptation and development of child. It is time to investigate easy adaptive in classroom and well-organised program to acquire general social skills for sheltered school students at a small county and islands.

• Journal of the Korean Institute of Landscape Architecture
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• v.45 no.3
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• pp.116-128
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• 2017

In this study, the original scenery of Baegun-dong Garden in Gangjin was compared with that of the reconstructed site to suggest directions for restoration in the future. The diachronic prototype scenery of the Baegun-dong Garden was derived by integrating the elements of the original and contemporary prototype sceneries from the old poetry series. The old poetry series is comprised of "Baegun-dong 8Yeong(詠)" by Lee Damro(李聃老), "Baegun-dong 10Su(首)" by Song Ikhwi(宋翼輝), "Baegun-dong 12Gyeong (景)" by Jeong Yakyong(丁若鏞), and "Baegun-dong 14Gyeong" by Lee Siheon (李時憲). Guidance for directions for future restoration was suggested through a comparative analysis between the diachronic prototype scenery of Baegun-dong Garden and the current scenery of the restored site. The research result is as follows. First, the prototype scenery of Baegun-dong Garden was a harmonic view composed of the camellia forest road, 'Baegun-dong' the letter carved on a rock, a cliff 'Changhabyeok(蒼霞壁)' the red letter written by Jeong Yakyong, paulownia trees, waterfalls and a maple forest. Outside the Byeolseo(別墅), there were a red plum blossom forest, a pine forest, and a bamboo forest, as well as the view of Okpanbong(玉版峯) from Jeongseondae(停仙臺). In the yard, there were Chwimiseonbang(翠微禪房), Jug-gak(竹閣), Pyeongsang(榻), a lotus Bangji(方池), Gogsugeo(曲水渠) and Hwagye(花階). Cranes were even raised in the yard. Second, comparing the diachronic prototype scenery of Baegun-dong Garden with its restored site, following a restoration guide is suggested. There should be more water flow in Baegun-dong Valley and Jug-gak should be restored. 'Changhabyeok' the red letter should be carved on the stone wall. Trees should be controlled for a better view of Okpanbong from Jeongseondae. More trees and plants, such as red plum blossom, pine tree, paulownia trees, azaleas(映山紅), chrysanthemum, orchid, daffodil, and lotus should be planted in the yard. A system of integrated guide boards is also required for effective information transmission for visitors.

• Information Systems Review
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• v.18 no.1
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• pp.157-175
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• 2016

Under the market economy of capitalism, several limitations reveal the inequity and redistribution problem of wealth, inefficiency of over-manufacturing and over-consumption, pollution of the natural environment, and the constraint of human liberty and dignity. The new challenge of symbiotic relationships that encourage individual corporations coincides with the need to practice social responsibility and share values to overcome these limitations. Social economy and the social enterprises that simultaneously pursue the making of corporate private profits and the realization of social values have been suggested and disseminated as alternative social value creators. Furthermore, the concept of a sharing economy, which refers to the sharing of things rather than owning them, is growing traction as a new paradigm of capitalism. However, these efforts of social enterprises have fallen short against the conflicts between private profit and social values. This study deals with the case of a start-up social corporation, "Purun Bike Sharing Inc.," which is based on a regional sharing economy business model about bike rental services that use Information and Communication Technology (ICT). This corporation pursues harmonic management to achieve a balance between private profit and social value. Its corporate mission is to achieve sharing, coexistence, and contribution for public welfare. This mission is a possible idea for use in the local community network as a core key for sustainable social enterprises. The model can also be an alternative approach to overcome the structural friction in the social corporation. This study considers the case of Purun Bike Sharing as a sustainable way to practice a sharing economy business model based on a regional cooperation network, which can be combined with social value, and to apply ICT to a sharing economy system. It also examines the definition and current state of social enterprises and the sharing economy, and the cases of the sharing economy business model for the review of prior research.

• Asia pacific journal of information systems
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• v.18 no.1
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• pp.79-96
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• 2008

One of the roles of the Semantic Web services is to execute dynamic intra-organizational services including the integration and interoperation of business processes. Since different organizations design their processes differently, the retrieval of similar semantic business processes is necessary in order to support inter-organizational collaborations. Most approaches for finding services that have certain features and support certain business processes have relied on some type of logical reasoning and exact matching. This paper presents our approach of using imprecise matching for expanding results from an exact matching engine to query the OWL(Web Ontology Language) MIT Process Handbook. MIT Process Handbook is an electronic repository of best-practice business processes. The Handbook is intended to help people: (1) redesigning organizational processes, (2) inventing new processes, and (3) sharing ideas about organizational practices. In order to use the MIT Process Handbook for process retrieval experiments, we had to export it into an OWL-based format. We model the Process Handbook meta-model in OWL and export the processes in the Handbook as instances of the meta-model. Next, we need to find a sizable number of queries and their corresponding correct answers in the Process Handbook. Many previous studies devised artificial dataset composed of randomly generated numbers without real meaning and used subjective ratings for correct answers and similarity values between processes. To generate a semantic-preserving test data set, we create 20 variants for each target process that are syntactically different but semantically equivalent using mutation operators. These variants represent the correct answers of the target process. We devise diverse similarity algorithms based on values of process attributes and structures of business processes. We use simple similarity algorithms for text retrieval such as TF-IDF and Levenshtein edit distance to devise our approaches, and utilize tree edit distance measure because semantic processes are appeared to have a graph structure. Also, we design similarity algorithms considering similarity of process structure such as part process, goal, and exception. Since we can identify relationships between semantic process and its subcomponents, this information can be utilized for calculating similarities between processes. Dice's coefficient and Jaccard similarity measures are utilized to calculate portion of overlaps between processes in diverse ways. We perform retrieval experiments to compare the performance of the devised similarity algorithms. We measure the retrieval performance in terms of precision, recall and F measure? the harmonic mean of precision and recall. The tree edit distance shows the poorest performance in terms of all measures. TF-IDF and the method incorporating TF-IDF measure and Levenshtein edit distance show better performances than other devised methods. These two measures are focused on similarity between name and descriptions of process. In addition, we calculate rank correlation coefficient, Kendall's tau b, between the number of process mutations and ranking of similarity values among the mutation sets. In this experiment, similarity measures based on process structure, such as Dice's, Jaccard, and derivatives of these measures, show greater coefficient than measures based on values of process attributes. However, the Lev-TFIDF-JaccardAll measure considering process structure and attributes' values together shows reasonably better performances in these two experiments. For retrieving semantic process, we can think that it's better to consider diverse aspects of process similarity such as process structure and values of process attributes. We generate semantic process data and its dataset for retrieval experiment from MIT Process Handbook repository. We suggest imprecise query algorithms that expand retrieval results from exact matching engine such as SPARQL, and compare the retrieval performances of the similarity algorithms. For the limitations and future work, we need to perform experiments with other dataset from other domain. And, since there are many similarity values from diverse measures, we may find better ways to identify relevant processes by applying these values simultaneously.

• Economic and Environmental Geology
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• v.18 no.1
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• pp.65-92
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• 1985

A total of 12 mineral commodities significant in domestic output, economy and/or strategy of the Republic of Korea are chosen to examine the structural changes in production and demand-supply of these minerals during the last two decades of her industrialization. These include iron and manganese ores as the raw materials for iron and steel making, copper, zinc and tungsten ores among other non-ferrous metallic minerals, limestone (cement), kaolin, talc, pyrophyllite and graphite among other non-metallic minerals, and anthracite coal as the only domestic source of fossil energy. These are reviewed historically in time-series based on the statistical data which are tabulated and graphed in terms of domestic output, export, import, apparent demand-supply, its increasing rate, and self-sufficiency rate of each commodity. The increasing rates of demand-supply (IRDS) of some more important commodities are compared with those of Gross Domestic Production (GDP) and Economic Growth Rate (EGR) to evaluate how the IRDS contributed to the GDP and EGR. The major results revealed are as follows: Among the 12 commodities, the domestic output of 8 commodities appeared to have grown with steady upward trends: they are ores of lead, zinc and tungsten, limestone (cement), kaolin, talc, pyrophyllite and anthracite coal. Two commodities, ores of iron and copper, continued with unchanging or slightly declining trends and varied fluctuations, in spite of their cardinal importance to the heavy industry and strategy of Korea. The remaining two, graphite and manganese ore, have gradualy declined in domestic output in which the former has still enough resource potential but the latter has not and virtually ceased its domestic output. Trade patterns for mineral commodities in the Republic of Korea during the last two decades have changed greatly, being marked by a shift from mineral-exporting to mineral importing, mainly because of increasing consumption of mineral raw materials for industrialization rather than beceuse of decreasing output of domestic mineral commodities in quantity. In terms of trade patterns, the 12 commodities concerned in this study can be classified into the following four groups. The 1st group - ores of lead and tungsten have only been exported without imports. The 2nd group - amorphous graphite, and pyrophyllite have mainly been exported but partly been imported. The 3rd group - kaolin, talc and crystalline graphite have equally been exported and imported, but quantity of imports have rapidly been increased with time. The 4th group - ores of iron, manganese and zinc have shifted from exports to imports during the industrialization, particularly owing to the initiation of iron and steel making by the Pohang Iron and Steel Company in the middle 1970' s and the new establishment of the Onsan Zinc Refinery in the late 1970' s. All of the 12 commodities under considerations were far above 100% in self-sufficiency rate before or in the early 1960' s. Recently, however, most of them have been declined to below 100% except for those of limestone (cement) and pyrophyllite. It is particularly serious to identify that the self-sufficiency rates of the three important metallic minerals, iron, copper and manganese ores in 1982 appeared to be 5.1%, 0.5%, and 0.01%, respectively. The average self-sufficiency rate of the total domestic minerals produced in 1982 was 14.4% (in value) for that year. Mining industry appeared to be extremely high in its intermediate demand rate whereas its intermediate input rate to be quite low indicating that mineral raw materials have been exerted strong forward linkage effects upon the other industries rather than backward linkage effects. In comparing the curves of increasing rates of demand-supply of several major minerals - iron ore, manganese ore, copper ore, limestone (cement), kaolin, and anthracite coal - with those of Gross Domestic Production and Economic Growth Rate drawn on every graph, it is clearly shown that the curves of increasing rates of demand-supply comprise around 6 to 7 periods of cycles which roughly harmonious with those of the curves of GDP and EGR, except for the curve of anthracite coal of which the configuration seems to have resulted from the (artificial) government's mineral policy rather than from economic free market mechanism. The harmonic feature of these curves well suggests that the increasing rates of demand-supply of major minerals have been significantly contributed to the GDP and EGR. In addition, the wider amplitudes of the iron, manganese and copper curves than those of the limestone (cement) and kaolin curves indicate that the contribution of the former, metallic commodities, has been greater than that of the latter, non-metallic commodities.