• Journal of the Korea Society of Computer and Information
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• v.16 no.2
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• pp.33-46
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• 2011

Since an e-mail has been an important mean of communication and information sharing, there have been much effort to classify e-mails efficiently by their contents. An e-mail has various forms in length and style, and words used in an e-mail are usually irregular. In addition, the criteria of an e-mail classification are subjective. As a result, it is quite difficult for the conventional text classification technique to be adapted to an e-mail classification efficiently. An e-mail classification technique in a commercial e-mail program uses a simple text filtering technique in an e-mail client. In the previous studies on automatic classification of an e-mail, the Naive Bayesian technique based on the probability has been used to improve the classification accuracy, and most of them are on an e-mail in English. This paper proposes the personalized recommendation technique of an email in Korean using a data mining technique of frequent patterns. The proposed technique consists of two phases such as the pre-processing of e-mails in an e-mail folder and the generating a profile for the e-mail folder. The generated profile is used for an e-mail to be classified into the most appropriate e-mail folder by the subjective criteria. The e-mail classification system is also implemented, which adapts the proposed technique.

• Proceedings of the Optical Society of Korea Conference
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• 2000.02a
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• pp.288-289
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• 2000

SBN, BSKNN KNSBN 등의 tungsten-bronze 계열에 속하는 광굴절 결정은 짧은 파장에서 좋은 감광도와 빠른 응답시간을 갖는다. 이중에서도 KNSBN 결정은 큰 크기의 결정 성장 및 도핑이 용이하고 광굴절 결정에서 중요한 특성 중 하나인 열 안정성(thermal stability)이 좋기 때문에 빠른 응답특성이 요구되는 응용분야에서 촉망받는 매질이다. 본 논문에서는 광정보저장, 광정보처리, 광컴퓨터, 광통신과 같은 다양한 분야에서 응용가능성을 가지는 Cu가 0.04wt.%도핑된 5mm$\times$5mm$\times$5mm 크기의 KNSBN 결정을 이용한 광신호의 증폭기술에 대하여 연구하였다. 먼저 Cu-KNSNB 결정의 2광파 결합 특성을 분석하기 위하여, 기록 파장에 따른 지수이득계수의 외부입사각의존성, 최대 지수이득계수를 나타내는 외부입사각에서 입사빔의 세기비에 따른 2광파 결합 이득을 측정하였다. 또한, 632.8nm파장 영역에서 기록 및 삭제시간 상수, 회절 효율의 입사빔 세기비 의존성을 측정하였다. 그리고, 음향-광학 변조기(AOM: acousto-optic modulator)에 의해 진폭 변조된 신호빔을 이용하여 광신호 증폭특성을 분석하고 그 결과를 제시하였다. 이때 두 빔의 입사각은 최대 지수이득계수를 나타내는 입사반각 12$^{\circ}$로 고정하고, 감쇄기를 이용하여 신호빔의 세기를 조절하면서 신호빔의 차동이득을 측정하였다. 투과된 신호빔은 같은 주파수에서 차동 이득(diffrerential gain)을 보였으며, 이는 moving grating과 시간-변조된 신호빔(또는 펌프빔)사이의 새로운 상호작용은 광굴절 결정의 시간 적분 특성에 의한 것이다. (중략) 경우는 상온에서 펌프 펄스의 유지시간이 0.5% 인 경우 레이저가 동작하는 것을 보여주었다. 이는 구조내에서 열전도가 문제가 된다는 것을 의미하는데 위아래가 공기로 둘러 싸여 있어 발생한 열이 가는 유전체 네트웍을 통해서만 전달 될 수 있기 때문이다. (중략)$^4$A$_2$에 의한 nophonon line R$_1$, R$_2$(680.4, 678.5 nm) 및 $^2$T$_1$$\longrightarrow$$^4$A$_2$(655.7, 649.3, 645.2 nm)의 형광방출 스펙트럼을 얻었으며, 형광수명은 0.264 ms로 조사되었다. 제조된 레이저 발진봉은 직경 6.3 m, 길이 45 nm이었다.\pm$0.06kHz Ge $F_4$; -1.84$\pm$0.04kHz$0.04kHz/TEX>0.04kHz 모국어 및 관련 외국어의 음운규칙만 알면 어느 학습대상 외국어에라도 적용할 수 있는 보편성을 지니는 것으로 사료된다.없다. 그렇다면 겹의문사를 [-wh]의리를 지 닌 의문사의 병렬로 분석할 수 없다. 예를 들어 누구누구를 [주구-이-ν가] [누구누구-이- ν가]로부터 생성되었다고 볼 수 없다. 그러므로 [-wh] 겹의문사는 복수 의미를 지닐 수 없 다. 그러면 단수 의미는 어떻게 생성되는가\ulcorner 본 논문에서는 표면적 형태에도 불구하고 [-wh]의미의 겹의문사는 병렬적 관계의 합성어가 아니라 내부구조를 지니지 않은 단순한 단어(minimal $X^{0}$ elements)로 가정한다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1992.10a
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• pp.59-64
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• 1992

터빈 블레이드와 같이 회전하는 구조물의 파단은 공진 근처에서 진동이 발 생할 때에 이에 기인하는 피로에 의하여 발생한다. 그러므로 이와 같은 파단 을 피하기 위해서는 설계 단계에서 이론적인 계산에 의하여 구조물의 고유 진동수를 결정하는 것이 상당히 중요하다. 판이 회전을 받게 되면 원심력에 의하여 판의 강성이 증가하므로 고유진동수가 회전하지 않는 판의 고유진동 수보다는 상당히 증가하게 된다. 이에 대한 연구가 국내외에서 상당수 행하 여졌지만, 연구의 대부분이 회전의 영향을 고려하지 않은 정지판(stationary plate)에 대한 것이며 뢰전을 고려한 연구는 극히 제한되어 있다. 또한 회전 의 영향을 고려한 연구의 대부분이 해석 대상을 보로서 단순화 시켰고 해법 으로는 유한요소법과 Ritz법 등을 사용하였다. 이는 블레이드가 지니고 있는 기하학적인 형상과 진동 특성이 해석적인 방법으로 해결하는 데에는 상당한 어려움이 있기 때문이다. 실제적으로는 터빈 블레이드와 같은 회전체의 진동 특성이 설치각이나 비틀림각, 판의 형상비, 회전속도 등의 변화에 의하여 영 향을 받기 때문에 보와 같은 진동 거동을 보이기보다는 판이나 셀과 같은 진동 거동을 보이므로 보다 정확한 해석을 수행하기 위해서는 해석 대상을 판이나 셀로서 취급하는 것이 타당하다. 따라서 본 연구에서는 위와 같은 이 유 때문에 해석 대상을 등방성 사각판과 직교이방성 복합재료 사각판으로 선택하였으며, 구조물의 고유진동수에 영향을 미치는 다음과 같은 인자들을 해석에 고려하였다. 1. 회전속도 (rotational speed) 2. 설치각 (setting angle) 3. 허브의 반경 (hub radius) 4. 판의 형상비 (aspect ratio) 5. 적층순서 (stacking sequence)구조물에 대한 동적실험(dynamic test)을 통하여 단기간에 동적특성을 결정하고 SDM(structure dynamic modification)이나 FRS(force response simulation)를 수행하여 임의의 좌표 공간에 대한 진동수준을 해석적으로 예측할 뿐만 아니라 구조물의 진동제어 를 위한 동적인자를 변경시킬 수 있는 정보를 제공하며 장비를 방진할 경우 신뢰성 있는 전달률을 결정할 수 있다. 실험적으로 철교, 교량이나 건물의 철골구조 및 2층 바닥 등 대,중형의 복잡한 구조물에 대항 동특성을 나타내 는 모빌리티를 결정할 경우 충격 가진 실험이 사용되는 실험장비 측면에서 나 실험을 수행하는 과정이 대체적으로 간편하다. 그러나 이 경우 대상 구조 물을 충분히 가진시킬수 있는 용량의 대형 충격기(large impact hammer)가 필요하게 된다. 이러한 동적실험은 약 길이 61m, 폭 16m의 4경간 교량에 대 하여 동적실험을 수행하여 가능성을 확인하였다. 여기서는 실험실 수준의 평 판모델을 제작하고 실제 현장에서 이루어질 수 있는 진동제어 구조물에 대 한 동적실험 및 FRS를 수행하는 과정과 동일하게 따름으로써 실제 발생할 수 있는 오차나 error를 실험실내의 차원에서 파악하여 진동원을 있는 구조 물에 대한 진동제어기술을 보유하고자 한다. 이용한 해마의 부피측정은 해마경화증 환자의 진단에 있어 육안적인 MR 진단이 어려운 제한된 경우에만 실제적 도움을 줄 수 있는 보조적인 방법으로 생각된다.ofile whereas relaxivity at high field is not affected by τS. On the other hand, the change in τV does not affect low field profile but stron

• Journal of the Korean Ceramic Society
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• v.40 no.7
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• pp.683-689
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• 2003

The cylindrical ${\gamma}$-alumina pellets were prepared using amorphous alumina and pore generating agent. Its were immersed in aqueous solution of the mixture of Fe(NO$_3$)$_3$.9$H_2O$ and $CH_3$COOH, Fe(NO$_3$)$_3$.9$H_2O$ and $CH_3$COOH and HNO$_3$, and Fe(NO$_3$)$_3$.9$H_2O$ and HNO$_3$. The pellets thus were hydrothermally treated at 20$0^{\circ}C$ for 3 h in autoclave, and were investigated morphologies and changes of crystal pore characteristics, $N_2$ adsorption and desorption isotherms, active sites and mechanical strength etc. According to the preparation method, acicular platelet pseudo-boehmite crystals of 0.1~0.3 ${\mu}{\textrm}{m}$ size were transformed into acicular pseudo-boehmite cristals of 0.5~2 ${\mu}{\textrm}{m}$ size having the same crystal structure. When ${\gamma}$-alumina pellets were immersed in aqueous solution of the mixture of Fe(NO$_3$)$_3$.9$H_2O$ and $CH_3$COOH and then were hydrothermally treated, pore volume between 100 $\AA$ and 1000 $\AA$ was increased from 0.34 ㏄/g to 0.86 ㏄/g, and the gap of $N_2$ adsorption and desorption hysteresis loop was decreased due to increasement of pore size. New active site that could adsorb the C-H functional group was created on the catalist. Also, mechanical strength of catalyst was increased from 1.06 ㎫ to 1.36 ㎫.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.8
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• pp.977-983
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• 2007

Recently, the number of systems which utilize wireless power transmission to a receiving module in a short distance is increasing. For efficient use of receiving space, coils are wound around the ferrite core to produce electromotive force(emf) in suppling power by wireless transmission. This paper analyzed the magnetic flux density distribution in the ferrite core in magnetic field environment which is uniformly oriented along to a single axis at 125kHz. For numerical analysis, Ansoft Maxwell which is applying the FEM(Finite Element Method) method was used. We studied the variations of the gathered magnetic fluxes to the changes of the relative permeabilities of the ferrite cores. Also we calculated the magnetic flux variation by shaving the ferrite core off for the groove of coil winding. Results showed that using a small ferrite core in magnetic field at 100kHz band can increase the amount of magnetic flux $3{\sim}4 times$ than without the core. The magnetic flux decreased 23% by shaving the core 0.5 mm on the periphery of 4.75 mm radius core with the relative permeability 800.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.7
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• pp.694-704
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• 2011

In this paper, we present a design of a 5th order Chebyshev interdigital band-pass filter using inverter and susceptance slope parameter values obtained from EM simulated multi-port Y-parameters. The shifted length of the resonator is determined when the frequency of the transmission zero is separated far away from the center frequency. For the initial dimensions of the interdigital filter, the filter is decomposed into the individual resonators, and the dimensions are obtained using EM Simulation of the decomposed resonators. However, the interdigital filter with the dimensions determined from the EM simulation of the decomposed resonators shows slightly distorted response from the desired frequency response due to the coupling between non-adjacent resonators. To obtain a EM simulation dataset, EM simulation for this filter is carried out by parameter sweep with constant ratio for the initial values. In this dataset, it is determined the final values for the filter by optimization. The fabricated filter by PCB shows an upper-shift of center frequency of about 70 MHz, which was caused by permittivity changed and tolerance of fabrication.

• Cartoon and Animation Studies
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• s.43
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• pp.211-230
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• 2016

First this research starts with agreement that comics is 'the sequential art'. It means that over two sequential panels makes how to recognize the story and this research owes to the connection of forward panel and backward panel. Webtoon, internet comics is also consisted to sequential panels. But only it is different with the publish comics by direction, shape, length and so on. So this research tries to make point of the connection between first panel and second panel. Especially it researches what types of connections between the last panel of first episode and the first panel of second one beyond the connections of panels at only episode. This research treats the types of gutter, 'connection' means to continue the same scenes or 'separation' does to devide the story and shows the new scenes. Weekly webtoon must have a kind of break time. The first panel of next episode should remind of the former story, it means easy technique. Otherwise some first panel don't show the same scenes or story so this study researches 130 artworks from the portal sites; Naver, Daum, mobile comics platform; Lezhin Comics and Toptoon, Corea.

• Korean Journal of Applied Biomechanics
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• v.19 no.1
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• pp.77-85
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• 2009

This study is aimed at providing information on injury prevention and skill improvement by inducing the accurate movements in exercise as well as understanding the principles of badminton drive movements. Movement displacement of racket head showed the similar patterns among those surveyed but, it seemed that slight differences resulted from external factors such as height, length of brachial and forearm and individual trend of swing locus. Regarding upper joint angle per phase, the angles of shoulder joint, elbow joint and wrist joint were closely associated in taking drive movements and they supported the segment order theory that power was conveyed from proximal into distal. It was shown that angular velocity of upper joint became larger in follow through movement after impact among all those surveyed, which meant the importance of follow through in racket sports such as badminton. In conclusion, this follow through movement acts as an important factor in racket sports in terms of pose stability maintenance, pose correction of movements and injury prevention of joints. In summary, when swings are made according to segment order theory, efficient movements can be taken.

• Journal of the Korea institute for structural maintenance and inspection
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• v.16 no.5
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• pp.112-120
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• 2012

A numerical model considering the internal vaporization and the creep effect, in the form of a analytical program, for tracing the behavior of high strength concrete(HSC) members exposed to fire is presented. The two stages, i.e., spalling procedure and fire resistance time, associated with the thermal, moisture flow, creep and structural analysis, for the prediction of fire resistance behavior are explained. The use of the analytical program for tracing the response of HSC member from the initial pre-loading stage to collapse, due to fire, is demonstrated. Moisture evaporates, when concrete is exposed to fire, not only at concrete surface but also at inside the concrete to adjust the equilibrium and transfer properties of moisture. Finite element method is employed to facilitate the moisture diffusion analysis for any position of member, so that the prediction method of the moisture distribution inside the concrete members at fire is developed. The validity of the numerical model used in this program is established by comparing the predictions from this program with results from others fire resistance tests. The analytical program can be used to predict the fire resistance of HSC members for any value of the significant parameters, such as load, sectional dimensions, member length, and concrete strength.

• Journal of Information Management
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• v.42 no.4
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• pp.137-154
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• 2011

A headword finding system is defined as an information retrieval system using a word gloss as a query. We use the gloss as a document in order to implement such a system. Generally the gloss is very short in length and then makes very difficult to find the most proper headword for a given query. To alleviate this problem, we expand the document using the concept of query expansion in information retrieval. In this paper, we use 2 document expansion methods : gloss expansion and similar word expansion. The former is the process of inserting glosses of words, which include in the document, into a seed document. The latter is also the process of inserting similar words into a seed document. We use a featureless clustering algorithm for getting the similar words. The performance (r-inclusion rate) amounts to almost 100% when the queries are word glosses and r is 16, and to 66.9% when the queries are written in person by users. Through several experiments, we have observed that the document expansions are very useful for the headword finding system. In the future, new measures including the r-inclusion rate of our proposed measure are required for performance evaluation of headword finding systems and new evaluation sets are also needed for objective assessment.