• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.30 no.7B
• /
• pp.450-463
• /
• 2005

This paper aims to find influencing factors for firms to adopt network equipments which based on Advanced Telecom Computing Architecture (ATCA). ATCA suggests a standardized specification for telecom equipments design. This new paradigm of developing network equipment provides benefits for network equipment manufacturers by reducing development time for new equipments with lower CapEx and OpEx. It also deliver oportunities for telecom services providers to exploit or test new services by replacing or upgrading part of total system with modular based network equipments. The research model basically depends on various researches based on Rogers' Innovation and Diffusion theory and it is verified through an empirical study for ninety-one domestic forms. Binary logistic regression was conducted to find the relationship between purchase intention and factors affecting new technology adoption. As a result, two factors such as scalability and cost/benefit effectiveness of the new system were statistically significant. Cluster analysis followed with those two variables. This helps TEMs (Telecom Equipments Manufacturers) get some implications on timing and target customers for diffusing the ATCA based technologies in the market.

• Journal of the Institute of Electronics Engineers of Korea SC
• /
• v.45 no.2
• /
• pp.45-54
• /
• 2008

In this paper, a dynamic GTS scheduling method based on IEEE 802.15.4 is proposed for wireless control system. The proposed method can guarantee a transmission of real-time periodic and sporadic data within the time frame in factory environment. The modified superframe of IEEE 802.15.4 was used to the dynamic scheduling method of real-time mixed traffic(periodic data, sporadic data, and non real-time message). By separating CFP and CAP properly, the sporadic and non real-time messages are transmitted effectively and guarantee real-time transmission within a deadline. The simulation results show the improvement of real-time performance of periodic and sporadic data.

• Journal of the Korean Home Economics Association
• /
• v.44 no.9
• /
• pp.31-39
• /
• 2006

This study was conducted to reproduce the two-piece sleeve pattern of the ladies' jacket of the 1890's for Korean women of the twenties who have the standard body type and the average size. Fourteen two-piece sleeve patterns of the ladies 'jacket of the 1890's were collected and drawn to actual size. The length and width proportion of the upper-sleeve and under-sleeve pattern of the ladies' jacket of the 1890's were similar to the two-piece sleeve pattern of jacket which we see now. The elbow line of the two-piece sleeve pattern of the ladies' jacket of the 1890's was lower than the two-piece sleeve of jacket of today. The cap of the sleeve of the ladies' jacket of the 1890's was gathered and this gave volume to the upper part of sleeve but the lower part of the sleeve was tight. The study pattern of two-piece sleeve pattern which had the characteristics of the sleeve pattern of the ladies' jacket of the 1890's was designed like for Korean women of the twenties who have the standard body type and the average size through modifications based on the evaluation of dressing on two occasions. The study pattern was evaluated to have the silhouette of the sleeve of the ladies' jacket of the 1890's and to fit Korean women of the twenties who have the standard body type and the average size with the sensory test.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.49 no.5
• /
• pp.37-43
• /
• 2012

The closed-loop multiple-input multiple-output (MIMO) system has been adopted by long term evolution (LTE) system. Many techniques are proposed to enhance the transmission of LTE's advanced version to meet the increasing requirement, in which differential codebook gains a lot of interest. Previous researches on designing differential codebooks focused on quasi-diagonal unitary matrix which cannot guarantee the equal gain property. The equal gain property is very important to uplink because the performance of uplink is very sensitive to the peak-to-average power ratio (PAPR). In this paper, we derive the analytical expression of average bit error rate and PAPR for differential precoding MIMO system. Using the analytical results, we investigate the performances of several differential precoding schemes considering non-linear amplifier at the transmitter. Some selected simulation results indicate that the conventional differential precoding schemes have good performances without the consideration of non-linear amplifier. While considering non-linear amplifier, the proposed differential codebook outperforms other differential precoding schemes because it maintains the equal gain per transmit antenna.

• Kyungpook Mathematical Journal
• /
• v.13 no.2
• /
• pp.235-240
• /
• 1973

A k-dimensional vector bundle is a bundle ${\xi}=(E,P,B,F^k)$ with fibre $F^k$ satisfying the local triviality, where F is the field of real numbers R or complex numbers C ([1], [2] and [3]). Let $Vect_k(X)$ be the set consisting of all isomorphism classes of k-dimensional vector bundles over the topological space X. Then $Vect_F(X)=\{Vect_k(X)\}_{k=0,1,{\cdots}}$ is a semigroup with Whitney sum (${\S}1$). For a pair (X, A) of topological spaces, a difference isomorphism over (X, A) is a vector bundle morphism ([2], [3]) ${\alpha}:{\xi}_0{\rightarrow}{\xi}_1$ such that the restriction ${\alpha}:{\xi}_0{\mid}A{\longrightarrow}{\xi}_1{\mid}A$ is an isomorphism. Let $S_k(X,A)$ be the set of all difference isomorphism classes over (X, A) of k-dimensional vector bundles over X with fibre $F^k$. Then $S_F(X,A)=\{S_k(X,A)\}_{k=0,1,{\cdots}}$, is a semigroup with Whitney Sum (${\S}2$). In this paper, we shall prove a relation between $Vect_F(X)$ and $S_F(X,A)$ under some conditions (Theorem 2, which is the main theorem of this paper). We shall use the following theorem in the paper. THEOREM 1. Let ${\xi}=(E,P,B)$ be a locally trivial bundle with fibre F, where (B, A) is a relative CW-complex. Then all cross sections S of ${\xi}{\mid}A$ prolong to a cross section $S^*$ of ${\xi}$ under either of the following hypothesis: (H1) The space F is (m-1)-connected for each $m{\leq}dim$ B. (H2) There is a relative CW-complex (Y, X) such that $B=Y{\times}I$ and $A=(X{\times}I)$ ${\cap}(Y{\times}O)$, where I=[0, 1]. (For proof see p.21 [2]).

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.34 no.2
• /
• pp.403-413
• /
• 2014

For the reliable design of the structural concrete by the strut-tie model approaches of current design codes, the effective strengths of concrete struts must be determined with sufficient accuracy. Many values and equations for the effective strengths have been suggested until now. As those are for the two-dimensional concrete struts, however, it is inappropriate to employ them in the strut-tie model designs of three-dimensional structural concretes. In this study, an approach, that determines the effective strengths of three-dimensional concrete struts consistently and accurately by reflecting the state of 3-dimensional stresses, the 3-dimensional failure criteria of concrete, the degree of cracks (or tensile strains of reinforcing bars crossing the struts), the strut's longitudinal length, the deviation angle between strut orientation and compressive principal stress flow, compressive strength of concrete, and the degree of concrete confinement by reinforcing bars, is proposed. To examine the validity of the proposed approach, the ultimate strength analyses of 115 reinforced concrete pile caps tested to failure by previous investigators were conducted by the ACI 318-11's strut-tie model approach with the existing and proposed effective strengths of concrete struts.

• Journal of the Ergonomics Society of Korea
• /
• v.31 no.1
• /
• pp.109-116
• /
• 2012

Objective: The aim of this study is to present a solution to problems in the services provided by the general hospitals by creating a user-centric environment through analyzing the User Journey Map and the User Context. Background: The rapid growth in aging population and the monopolization of superior medical staffs by the general hospitals increased demand for the general hospitals in Korea. But, often services provided by the general hospitals are provider-centric and low quality. Method: This study examines problems in the services provided by the general hospitals by analyzing the User Journey Map through stakeholder interviews(contextual interviews) and on-site observation. Based on the contextual analysis of the user(i.e. the patient), this study proposes new and improved user-centric services to be provided by the general hospitals. Results: Ten new user-centric services proposed by this study are: (1) "Booklet on Success Story", (2) "FAQs by Doctor", (3) "Designated Nurse", (4) "Patient Interview Record Card", (5) "Close relationship between doctor & patient", (6) "Thank You Notice Board", (7) "Step by Step", (8) "Green Cap", (9) "Patient Kit", (10) "RFID Direction Display System". Conclusion: The service design for the general hospitals proposed by this study is an important case-study on improving the environment of the general hospitals from provider(medical staffs)-centric to user(patents and its family)-centric. Application: This study is expected to be used in various areas to improve existing system(products and/or services) to be more user-centric.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.36 no.1
• /
• pp.99-111
• /
• 2012

This paper investigates the formative features and the historical meaning of the Korean dress collection held in the Horniman Museum in London. The Museum holds eighteen items of Korean dresses donated by Mrs. C. de J. Luxmore in 1948 and by Mrs. Bowra in 1953. Male dresses consist of white silk outer robe (durumagi), a pale violet silk waistcoat (jokki), a jade green silk jacket (jeogori), pale yellow silk trousers (baji), a pair of ankle bands (daenim), a cotton waistband (dae), a silk purse (jumeoni), a rattan under-vest (deungbaeja), a pair of rattan wristlets (deungtosi), a top hat (gat) and a skullcap (tanggeon). Female dresses comprise a jade green silk jacket (jeogori), an ivory silk skirt (chima), a light blue silk petticoat (sokchima), two kinds of white cotton trousers (sokbaji and soksokgot), a pair of silk wristlets (tosi) and a pair of padded socks (beoseon). A Korean dress collection of the Horniman Museum shows a set of ordinary dress items worn by a married couple in the 1930s and the 1940s. Of these items, a silk petticoat (sokchima) and a rattan under-vest (deungbaeja) can be highly evaluated as object resources in the history of Korean dress. The petticoat is a rare and valuable example that represents an early type of modern petticoat that has replaced a traditional petticoat (dansokgot). The rattan under-vest has square neckline and two tiny sleeves similar to a Western cap sleeve. This kind of under-vest is a transitional form shown between under-vest similar to the Korean waistcoat (baeja) and one similar to the Western waistcoat (jokki).

• Journal of Ecology and Environment
• /
• v.35 no.1
• /
• pp.1-7
• /
• 2012

To calculate and predict soil carbon budget and cycle, it is important to understand the complex interrelationships involved in soil respiration rate (Rs). We attempted to reveal relationships between Rs and key environmental factors, such as soil temperature, using a laboratory incubation method. Soil samples were collected from mature deciduous (MD), mature coniferous (MC), immature deciduous (ID), and immature coniferous (IC) forests. Prior to measure, soils were pre-incubated for 3 days at $25^{\circ}C$ and 60% of maximum water holding capacity (WHC). Samples of gasses were collected with 0, 2, and 4 h interval after the beginning of the measurement at soil temperatures of 5, 15, 25, and $35^{\circ}C$ (at 60% WHC). Air samples were collected using a syringe attached to the cap of closed bottles that contained the soil samples. The $CO_2$ concentration of each gas sample was measured by gas chromatography. Rs was strongly correlated with soil temperature (r, 0.93 to 0.96; P < 0.001). For MD, MC, ID, and IC soils taken from 0-5 cm below the surface, exponential functions explained 90%, 82%, 92%, and 86% of the respective data plots. The temperature and Rs data for soil taken from 5-10 cm beneath the surface at MD, MC, ID, and IC sites also closely fit exponential functions, with 83%, 95%, 87%, and 89% of the data points, respectively, fitting an exponential curve. The soil organic content in mature forests was significantly higher than in soils from immature forests (P < 0.001 at 0-5 cm and P < 0.005 at 5-10 cm) and surface layer (P = 0.04 at 0-5 cm and P = 0.12). High soil organic matter content is clearly associated with high Rs, especially in the surface layer. We determined that the incubation method used in this study have the possibility for comprehending complex characteristic of Rs.

• Journal of Astronomy and Space Sciences
• /
• v.37 no.2
• /
• pp.143-156
• /
• 2020

Korea Polar Research Institute (KOPRI) installed an ionospheric sounding radar system called Vertical Incidence Pulsed Ionospheric Radar (VIPIR) at Jang Bogo Station (JBS) in 2015 in order to routinely monitor the state of the ionosphere in the auroral oval and polar cap regions. Since 2017, after two-year test operation, it has been continuously operated to produce various ionospheric parameters. In this article, we will introduce the characteristics of the JBS-VIPIR observations and possible applications of the data for the study on the polar ionosphere. The JBS-VIPIR utilizes a log periodic transmit antenna that transmits 0.5-25 MHz radio waves, and a receiving array of 8 dipole antennas. It is operated in the Dynasonde B-mode pulse scheme and utilizes the 3-D inversion program, called NeXtYZ, for the data acquisition and processing, instead of the conventional 1-D inversion procedure as used in the most of digisonde observations. The JBS-VIPIR outputs include the height profiles of the electron density, ionospheric tilts, and ion drifts with a 2-minute temporal resolution in the bottomside ionosphere. With these observations, possible research applications will be briefly described in combination with other observations for the aurora, the neutral atmosphere and the magnetosphere simultaneously conducted at JBS.