• Journal of the Institute of Convergence Signal Processing
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• v.13 no.4
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• pp.194-200
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• 2012

In this paper we analyze the code sequence generating algorism defined on $GF(2^n)$ proposed by S.Bostas and V.Kumar[7] and derive the implementation functions of code sequence generator using Boolean functions which can map the vector space $F_2^n$ of all binary vectors of length n, to the finite field with two elements $F_2$. We find the code sequence generating boolean functions based on two kinds of the primitive polynomials of degree, n=5 and n=7 from trace function. We then design and implement the code sequence generators using these functions, and produce two code sequence groups. The two groups have the period 31 and 127 and the magnitudes of out of phase(${\tau}{\neq}0$) autocorrelation and crosscorrelation functions {-9, -1, 7} and {-17, -1, 15}, satisfying the period $L=2^n-1$ and the correlation functions $R_{ij}({\tau})=\{-2^{(n+1)/2}-1,-1,2^{(n+l)/2}-1\}$ respectively. Through these results, we confirm that the code sequence generators using boolean functions are designed and implemented correctly.

• Proceedings of the Korean Society for Language and Information Conference
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• 2001.06a
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• pp.95-96
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• 2001

문장에서 술어를 수식하는 대표적인 표현은 부사어이다. 부사어는 일반적으로 문장 구성에서 핵심적 역할을 하지 않는 첨가어(adjuncts)이기 때문에 핵심적인 역할을 하는 보충어(complements)에 비해 상대적으로 연구가 덜 이루어진 분야이다. 그렇지만 부사어는 피수식어의 의미를 구체화/한정하는 기능을 하기 때문에 정확한 의사소통을 위해서는 반드시 필요한 요소이며 어순, 호응(concord)등의 통사적 현상과도 밀접한 관련이 있다. 이 연구의 일차적 목적은 이러한 부사어를 통사적, 의미적 기준에 의해 정확하게 분류하고 그들의 분포제약을 밝히는 것이다. 그 다음으로, 부사어와 관련된 통사 현상으로, 부사어와 피수식어의 공 기(co-occurrence)관계 및 부사어와 술어 어미의 호응 관계에 대한 분석을 제공하려고 한다. 부사어는 통사적인 기준과 의미적인 기준으로 분류할 수 있다 (손남익 1995, 김경훈 1996, 임유종 1998). 통사적 기준으로는 단어나 구를 수식하는 성분부사와 문장을 수식하는 문장 부사로 나누는 방법과 위치에 대한 제약이 있느냐 없느냐에 따라 제약부사와 자유부사로 나 누는 방법이 있다. 이 두 통사론적 기준에 의해 분류되는 부사들은 서로 어떤 상관관계를 보이고 있는지 살펴 볼 것이다. 일반적으로 문장부사는 문두에 놓여야 한다는 위치적 제 약 이 있기 때문에 제약부사로 분류된다. 의미적 기준으로 부사어를 분류할 수도 있는데, 시간/ 공간 부사어, 양태/정도 부사어 등으로 나눌 수 있다. 의미적 기준에 의해 분류된 부사어는 통사적 기준에 의해 분류된 것들과는 어떤 상호 관련성을 맺고 있는지 살펴 볼 것이다. 일 반적으로 시간부사와 장소부사는 자유부사에 속하며 양태부사와 정도부사는 제약부사에 속 한다. 부사어와 피수식 요소와의 통사적 공기 관계 및 의미적 관계 그리고 그와 관련된 문 법 현상도 연구의 대상이 된다. 예를 들어, 자유로운 어순을 가진 부사들이지만 “＊순이는 빨리 과연 달린다”에서 볼 수 있는 종류의 분포적 특성을 알아 볼것이다 (심재기 1982, 송 철의 1989). 또한 “길이/＊길게 빛나다”와 “＊길이/길게 드리워졌다”와 같은 대조에서 나타나는 통사, 의미적 기능의 상관 관계 및 제약들의 상호 작용도 살펴 볼 것이다.

• Journal of Korean Tunnelling and Underground Space Association
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• v.7 no.3
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• pp.259-267
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• 2005

This paper analyzed characteristic of temperature change as well as bottom of tunnel with thermometer according to tunnel length and region during one year. And it measured temperature distribution near tunnel portal. In the paper it was known that tunnel entrance and exit have different characteristic temperature distribution in accordiance with bottom of tunnel per tunnel length. Temperature of tunnel changed from tunnel exit to fifty meter and distribution of tunnel temperature was established uniform regardless of tunnel length. But temperature distribution of tunnel changed in tunnel entrance differ from tunnel exit in the location of one hundred twenty five meter and one hundred fifty meter. Cold air inflowed from tunnel entrance have influenced with the location of one hundred twenty five meter and one hundred fifty meter.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.7
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• pp.237-244
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• 2016

The workability of mortar determines its construction performance in a structure showing its designed resistance to external loads. Measuring the rheological properties of mortar is one way of quantifying its workability, but its field-applications are limited due to economical and spatial issues. The robustness of the slump flow test allows its use for evaluating the workability of mortar, even though it is a rather qualitative test method. This paper proposes a channel flow test and develops a correlation between its result and the rheological properties of mortar. The volume-of-fluid simulation for the channel flow test was accomplished, and a numerical database for the correlation was composed. A correlation model to estimate the rheological properties of mortar using the results of the channel flow test as inputs is proposed.

• The Journal of Engineering Geology
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• v.16 no.4 s.50
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• pp.381-392
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• 2006

The passive surface wave survey using microtremor is conducted in areas of crystalline rock basements to obtain average shear-wave velocity structures to 30 m deep (Vs30), on which the earthquake-resistant design standard is based. Test data were recorded at two sites with triangular and L-shaped arrays for 4 seconds with an sampling interval of 2 ms. The microtremor recorded at a site were analysed using the spatial autocorrelation method to obtain phase-velocity spectra and effects of major factors such as size and shape of away and number of record and receiver were examined. At the other site, shear-wave velocities were derived from VSP and microtremor data separately. The results from these two methods agree to each other reasonably well, indicating that the microtremor method can be an effective geophysical tool to measure Vs30.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.33 no.1
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• pp.23-34
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• 2013

In this study, a safe, economic, and rapid construction method of underground roadway using PSC girder is developed to reduce traffic congestion and maximize space usage in urban area. For an efficient application of the method, a rigid joint connection is proposed and tested. For the testing, cantilever specimens were used to verify its capacity. The parameters for this study were cross beam length and joint connection type. The results of the test showed that the proposed connection system has superior performances. Despite having differences of cross beam length and joint connection type, the stable flexural behavior was shown in all of the tested specimens. Also, the behaviors of PSC girders and upper slabs connected by the proposed method showed superior performance. Moreover, the improvement of structure performance according to the increase of length of cross beams has been verified.

• Journal of the korean academy of Pediatric Dentistry
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• v.47 no.2
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• pp.176-187
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• 2020

The purpose of this study is to evaluate validity, reliability and reproducibility of tooth width (TW), arch length (AL) and arch length discrepancy (ALD) measured on a digital model taken via 3-dimensional model scanner and intraoral scanner compared to a plaster model. A total of 30 patients aged 12 to 18 were eligible for the study. 3 types of models were acquired from each patient: a conventional plaster model (P), a model scanned digital model (MSD) taken via Freedom UHD^® and an intraoral scanned digital model (ISD) taken via CS3600^® in-vivo. The reliability of TW and AL in each group was evaluated using Pearson's correlation coefficient, while the reproducibility was evaluated with intraclass correlation coefficient. The validity of space analysis was assessed by paired t-test. As a result, all measurements of P, MSD and ISD groups showed favorable reliability and reproducibility. Most of measurements for space analysis in MSD group and TW in ISD group also presented high validity. AL and ALD presented statistically significant difference between P and ISD group. The validity of measurements of space analysis in ISD group was short in doubt to valid, but clinically acceptable. Both MSD and ISD are clinically acceptable to use for space analysis but clinician should be aware that errors can be found using a digital model.

• The korean journal of orthodontics
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• v.33 no.4 s.99
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• pp.223-233
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• 2003

The Purpose of this study was to Investigate the relationship between the space discrepancy of the mandibular dentition and craiofacial morphology in adults with good Angle class I occlusion. Dental casts of normal group, crowded group and spaced group were selected on the basis of dental crowding and spacing. Subjects with excessive space to accomodate the lower teeth were classified as spaced group(39). Subjects with a space discrepancy of more than 4mm were classified as crowded group(45). Normal subjects had little or no dental crowding and spacing(40). Various skeletodental measurements in lateral cephalograms were evaluated and compared by ANOVA, Pearson correlation analysis and multiple stepwise regression analysis. The results were as follows; 1. ANB angle was larger in crowded group than in spaced group. 2. Maxilla and mandible in crowded group were inclined more downward and forward than in spaced group, so crowded group was found to have vortical tendency. 3. Anterior cranial base length and mandibular body length were longer in spaced group than in crowded group. 4. According to the multiple stepwise regression analysis with space discrepancy as dependent variable, 40% of variance of space discrepancy could be explained by ANB angle, anterior facial height and ramus height. Multiple regression equation was as follows Space discrepancy=46.51-2.51ANB-0.58AFH+0.65RH

• Journal of the Korea Institute of Information and Communication Engineering
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• v.10 no.5
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• pp.910-920
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• 2006

We consider the problem of estimating a code-timing of DS-CDMA signal in antenna array systems in the presence of flat fading channels and near-far environments. We derive an approximate maximum likelihood algorithm of estimating the code-timing of a desired user for DS-CDMA systems to better utilize the time-varying characteristics of the fading process. In the development of code timing estimator, the given observation bits are divided into many sets of sub-windows with each sufficiently large. The proposed method uses sub-windows with equal size associated with the coherence time of channel fading. The alternative approach is that without the estimation of the fading rate, the sufficiently given observation bits are simply separated into two consecutive sets of sub-windows. The derivation of the proposed algorithms is based on multiple antennas partially correlated in space. The impacts of spatial fading correlation on acquisition and men acquisition time performance of the proposed algorithms are also examined.

• Journal of Korean Tunnelling and Underground Space Association
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• v.22 no.4
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• pp.451-468
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• 2020

Aging tunnels with small cross-sections can cause chronic traffic jams. This problem can be solved by widening the tunnel. In general, when the tunnel is expanded, the outer portion of the existing tunnel is excavated through a mechanical or blasting method. Such excavation affects not only the surrounding ground but also the existing tunnel. The application of the pre-cutting method can be a solution to these problems effectively. Therefore, if the widening of tunnel is performed by applying pre-cutting method, analysis of the impact of this method must be performed. In this study, in order to analyze the effect of applying pre-cutting in tunnel widening, numerical analysis is performed at six ground grades, from grade I to weathered rock. The analysis is performed with the expanding lane and the excavation length of pre-cutting as variables. In addition, the analysis is focused on the displacement of crown of the existing tunnel and the enlarged tunnel. As a result, the crown displacement of the enlarged tunnel is confirmed to converge at the same value regardless of the excavation length of the pre-cutting when the tunnel widening is completed. In the case of existing tunnels, uplift of crown occurs within 5 m of the front of the tunnel surface, and the shorter the excavation length of pre-cutting is found to be effective in preventing the occurrence of uplift.