• The Journal of Korean Institute of Communications and Information Sciences
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• v.37C no.10
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• pp.977-985
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• 2012

Recently, many countries have been developing new protocols to improve the performance of tactical ad hoc networks for implementing NCW (Network Centric Warfare). Combat net radio (CNR) networks are the most important communication infra for the ground forces such as infantry of Army. U.S. Army had developed MIL-STD-188-220D that is the Interoperability Standard for DMTDs (Digital Messages Transfer Device Subsystems) for voice and data communication in CNR. MIL-STD-188-220D is a candidate for MAC protocol of TMMR which is next radio and has a few constraints to used in TMMR. NAD (Network Access Delay) defined in MIL-STD-188-220D needs time synchronization to avoid collision. However, it is difficult for time synchronization to fit in multi-hop environment. We suggest the enhanced DAP (Deterministic Adaptable Priority)-NAD to prevent conflicts and decrease delays in multi-hop CNR. Simulation results show that the proposed scheme improves the performance in multi-hop CNR networks.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.26 no.5
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• pp.731-742
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• 2022

PIPO is the latest domestic lightweight block cipher announced in ICISC'20, which is characterized by being lightweight to facilitate implementation on IoT with limited resources. In this paper, PIPO 64/128-bit and 64/256-bit were implemented using web-based languages such as Javascript and WebAsembly. Two methods of performance evaluation were conducted by implementing bitsice and TLU, and the performance was compared by implementing Looped written using for statements and Unrolled written for statements. It performs performance evaluations in various web browsers such as Google Chrome, Mozilla Firefox, Opera, and Microsoft Edge, as well as OS-specific environments such as Windows, Linux, Mac, iOS, and Android. In addition, a performance comparison was performed with PIPO implemented in C language. This can be used as an indicator for applying PIPO block cipher on the web.

• Journal of the Korean Mathematical Society
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• v.42 no.1
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• pp.111-127
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• 2005

Let B and S be the unit ball and the unit sphere in $\mathbb{C}^n$, respectively. Let ${\sigma}$ be the normalized Lebesgue measure on S. Define the Privalov spaces $N^P(B)\;(1\;<\;p\;<\;{\infty})$ by $$N^P(B)\;=\;\{\;f\;{\in}\;H(B) : \sup_{0 where H(B) is the space of all holomorphic functions in B. Let ${\varphi}$ be a holomorphic self-map of B. Let ${\mu}$ denote the pull-back measure ${\sigma}o({\varphi}^{\ast})^{-1}$. In this paper, we prove that the composition operator $C_{\varphi}$ is metrically bounded on $N^P$(B) if and only if ${\mu}(S(\zeta,\delta)){\le}C{\delta}^n$ for some constant C and $C_{\varphi}$ is metrically compact on $N^P(B)$ if and only if ${\mu}(S(\zeta,\delta))=o({\delta}^n)$ as ${\delta}\;{\downarrow}\;0$ uniformly in ${\zeta}\;\in\;S. Our results are an analogous results for Mac Cluer's Carleson-measure criterion for the boundedness or compactness of $C_{\varphi}$ on the Hardy spaces $H^P(B)$.

• Language and Information
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• v.17 no.2
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• pp.29-50
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• 2013

Multiple Nominative Constructions (MNCs) and Multiple Accusative Constructions (MACs) have been some of the hottest and interesting topics in Korean syntax. This paper took empirical approaches to these constructions and examined native speakers' grammaticality judgements of these constructions. Though there are lots of previous studies on these constructions, Ryu (2010, 2013a, 2013b, 2013c) recently tried to unify MNCs and MACs into Multiple Case Constructions (MCCs) and to classify them into 16 types based on the semantic relations. This paper includes experiments which were performed on these 16 different types. The experiments were designed following Johnson (2008); and the native speakers' intuition was measured with two scales, numerical estimates and line drawing, though the latter was adopted in the actual analyses. Through the experiment, the following facts were observed: (i) the grammaticality of the MCCs varies depending on their semantic relations, (ii) MNCs were more grammatical than MACs if both constructions occurred in similar environments, and (iii) the sentences in some MAC types had much lower grammaticality than those in the others, as Ryu (2013b, 2013c) mentioned.

• Kyungpook Mathematical Journal
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• v.45 no.1
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• pp.45-53
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• 2005

A basis of the cycle space C (G) is d-fold if each edge occurs in at most d cycles of C(G). The basis number, b(G), of a graph G is defined to be the least integer d such that G has a d-fold basis for its cycle space. MacLane proved that a graph G is planar if and only if $b(G)\;{\leq}\;2$. Schmeichel showed that for $n\;{\geq}\;5,\;b(K_{n}\;{\bullet}\;P_{2})\;{\leq}\;1\;+\;b(K_n)$. Ali proved that for n, $m\;{\geq}\;5,\;b(K_n\;{\bullet}\;K_m)\;{\leq}\;3\;+\;b(K_n)\;+\;b(K_m)$. In this paper, we give an upper bound for the basis number of the semi-strong product of a bipartite graph with a cycle.

• Electronics and Telecommunications Trends
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• v.25 no.4
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• pp.27-37
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• 2010

최근 들어 무선 센서네트워크는 온/습도 관리와 같은 단순한 기능의 저전력 모니터링 서비스에서 시의성과 무선 전송의 신뢰성을 요구하는 산업 자동화 서비스 및 스마트 그리드와 같이 통신 거리를 확장한 옥외 서비스를 위한 기술로 서비스 영역을 넓혀가고 있다. 무선 센서네트워크 기술은 자원의 제약에 기인한 고유의 특성을 갖는다. 특히 전송 계층 기술은 이러한 제약 사항을 고려하여 설계되어야 하며, 상위 계층 기술의 성능은 전송기술에 대한 성능적 의존성을 가질 수 밖에 없다. 본 고에서는 최근 무선센서 네트워크 서비스 확대를 위한 시장의 요구사항을 반영하여 표준화가 진행되고 있는 시의성/신뢰성 향상을 위한 IEEE 802 WG15의 TG4e MAC 기술과 스마트 유틸리티 네트워크를 위한 TG4g SUN PHY 기술에 대한 표준화 활동을 중심으로 표준 기술 동향을 소개하고 이에 대한 표준 전략을 분석한다.

• 한국정보통신설비학회:학술대회논문집
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• 2008.08a
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• pp.327-330
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• 2008

This paper shows an implementation of WLAN-based Audio/Video(A/V) system for multimedia home networks. Proposed WLAN-based A/V system can transmit multimedia data of high quality. The entire system consists of a 16-bit RISC controller, a program ROM, a SRAM, timers, an interrupt controller, a DART, GPIOs, an I2C and the OFDM modem supporting for the IEEE 802.11g standard. The simple MAC functions are implemented by firmware on an embedded 16-bit RISC controller. The OFDM modem supports a complete set of data rates up to 54Mbps. Proposed the system is implemented by an Altera FPGA EP1S60F1020C6 device, a 10-bit 2-ch DAC, a 10-bit 2-ch ADC and RF/IF chips.

• Journal of the Korean Mathematical Society
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• v.41 no.1
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• pp.65-76
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• 2004

An entire function $f\;{\in}\;H(\mathbb{C})$ is called universal with respect to translations if for any $g\;{\in}\;H(\mathbb{C}),\;R\;>\;0,\;and\;{\epsilon}\;>\;0$, there is $n\;{\in}\;{\mathbb{N}}$ such that $$\mid$f(z\;+\;n)\;-\;g(z)$\mid$\;<\;{\epsilon}$ whenever $$\mid$z$\mid$\;{\leq}\;R$. Similarly, it is universal with respect to differentiation if for any g, R, and $\epsilon$, there is n such that $$\mid$f^{(n)}(z)\;-\;g(z)$\mid$\;<\;{\epsilon}\;for\;$\mid$z$\mid$\;{\leq}\;R$. In this note, we review G. MacLane's proof of the existence of universal functions with respect to differentiation, and we give a simplified proof of G. D. Birkhoff's theorem showing the existence of universal functions with respect to translation. We also discuss Godefroy and Shapiro's extension of these results to convolution operators as well as some new, related results and problems.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05d
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• pp.34-39
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• 1996

A series of measurements was peformed between KAERI and PNNL, U.S.A at KAERI secondary calibration laboratory to intercompare and verify the KAERI reference photon radiation fields by using air equivalent plastic walled ionization chambers, Different ionization chambers of two laboratories were used to determine the air kerma rate, free-in-air, at reference positions in the KAERI photon radiation fields, As the results, the agreement in the cross measurements between two laboratories was found to be within less than ${\pm}$ 3 %. This degree of consistency was considered to be encouraging, because each laboratory maintains independently its calibration traceablity with its national primary standard

• Radiation Oncology Journal
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• v.18 no.3
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• pp.194-199
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• 2000

Purpose : Then determining the lower margin of post-operative pelvic radiation therapy field according to the traditional method (recommended by Gunderson), the organs located in the low pelvic cavity and the perineum are vulnerable to unnecessary radiation. This study evaluated the effect of individualized determination of the lower margin at 2 cm to 3 cm below the anastomotic site on the failure patterns. Materials and Methods . Authors included ぉ patients with modified Astler-Coiler (MAC) stages from B2 through C3, who received low anterior resection and post-operative pelvic radiation therapy from Sept. 1994 to May 1998 at Samsung Medical Center, Sungkyunkwan University. The numbers of male and female patients were 44 and 44, and the median age was 57 years (range: 32-81 years). Three field technique (posterior-anterior and bilateral portals) by 6, 10, 15 MV X-rays was used to deliver 4,500 cGy to the whole pelvis followed by Sn cGy's small field boost to the tumor bed over 5.5 weeks. Sixteen patients received radiation therapy by traditional field margin determination, and the lower margin was set either at the low margin of the obturator foramen or at 2 cm to 3 cm below the anastomotic site, whichever is lower. In 72 patients, the lower margin was set at 2 cm to 3 cm below the anastomotic site, irrespectively of the obturator foramen, by which the reduction of radiation volume was possible in 55 patients ($76\%$). Authors evaluated and compared survival, local control, and disease-free survival rates of these two groups. Results : The median follow-up period was 27 months (range : 7-58 months). MAC stages B2 in 32($36\%$), B3 in 2 ($2\%$), Cl in 2 ($2\%$), C2 in 50 ($57\%$), and C3 in 2 ($2\%$) Patients, respectively. The entire patients' overall survival rates at 2 and 4 years were $94\%$ and $68\%$, respectively, and disease-free survival rates at 2 and 4 years were $86\%$ and $58\%$, respectively. The first failure sites were local only in 4, distant only in 14, and combined local and distant in 1 patient, respectively. There was no significant difference with respect to local control and disease-free survival rates ( p=0.42, p=0.68) between two groups of different lower margin determination policies. Conclusion : The new concept in the individualized determination of the lower margin depending on the anastomotic site has led to the equivalent local control and disease-free survival rates, and is expected to contribute to the reduction of unnecessary radiation-related morbidity by reduction of radiation volume, compared with the traditional method of lower margin determination.