• Phonetics and Speech Sciences
• /
• v.11 no.4
• /
• pp.45-53
• /
• 2019

The purpose of this work was to examine the factors affecting the identities of the voiceless plosives, i.e. English [p, t, k] and Korean [p^h, t^h, k^h], from the spontaneous speech corpora. The factors were automatically extracted by a Praat script and the percent correctness of the discriminant analyses was incrementally assessed by increasing the number of factors used in predicting the identities of the plosives. The factors included the spectral moments and tilts of the plosive release bursts, the post-burst aspirations and the vowel onsets, the durations such as the closure durations and the voice onset times (VOTs), the locations within words and utterances and the identities of the following vowels. The results showed that as the number of factors increased up to five, so did the percent correctness of the analyses, resulting in 74.6% for English and 66.4% for Korean. However, the optimal number of factors for the maximum percent correctness was four, i.e. the spectral moments and tilts of the release bursts and the following vowels, the closure durations and the VOTs. This suggests that the identities of the voiceless plosives are mostly determined by their internal and vowel onset cues.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.41 no.3
• /
• pp.187-187
• /
• 2004

In this paper, we present an efficient architecture of a versatile Reed-Solomon (RS) decoder which can be programmed to decode RS codes continuously with my message length k as well as any block length n. This unique feature eliminates the need of inserting zeros for decoding shortened RS codes. Also, the values of the parameters n and k, hence the error-correcting capability t can be altered at every codeword block. The decoder permits 3-step pipelined processing based on the modified Euclid's algorithm (MEA). Since each step can be driven by a separate clock, the decoder can operate just as 2-step pipeline processing by employing the faster clock in step 2 and/or step 3. Also, the decoder can be used even in the case that the input clock is different from the output clock. Each step is designed to have a structure suitable for decoding RS codes with varying block length. A new architecture for the MEA is designed for variable values of the t. The operating length of the shift registers in the MEA block is shortened by one, and it can be varied according to the different values of the t. To maintain the throughput rate with less circuitry, the MEA block uses both the recursive technique and the over-clocking technique. The decoder can decodes codeword received not only in a burst mode, but also in a continuous mode. It can be used in a wide range of applications because of its versatility. The adaptive RS decoder over GF($2^8$) having the error-correcting capability of upto 10 has been designed in VHDL, and successfully synthesized in an FPGA chip.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.41 no.3
• /
• pp.29-38
• /
• 2004

In this paper, we present an efficient architecture of a versatile Reed-Solomon (RS) decoder which can be programmed to decode RS codes continuously with my message length k as well as any block length n. This unique feature eliminates the need of inserting zeros for decoding shortened RS codes. Also, the values of the parameters n and k, hence the error-correcting capability t can be altered at every codeword block. The decoder permits 3-step pipelined processing based on the modified Euclid's algorithm (MEA). Since each step can be driven by a separate clock, the decoder can operate just as 2-step pipeline processing by employing the faster clock in step 2 and/or step 3. Also, the decoder can be used even in the case that the input clock is different from the output clock. Each step is designed to have a structure suitable for decoding RS codes with varying block length. A new architecture for the MEA is designed for variable values of the t. The operating length of the shift registers in the MEA block is shortened by one, and it can be varied according to the different values of the t. To maintain the throughput rate with less circuitry, the MEA block uses both the recursive technique and the over-clocking technique. The decoder can decodes codeword received not only in a burst mode, but also in a continuous mode. It can be used in a wide range of applications because of its versatility. The adaptive RS decoder over GF(2$^{8}$ ) having the error-correcting capability of upto 10 has been designed in VHDL, and successfully synthesized in an FPGA chip.

• Journal of the Institute of Electronics Engineers of Korea TC
• /
• v.41 no.5
• /
• pp.37-45
• /
• 2004

As Internet technologies are mature, many new applications that are different characteristics are emerging. Recently we see wide use of P2P(Peer to Peer) applications of which traffic shows different statistical characteristics compared with traditional application such as web(HTTP) and FTP(File Transfer Protocol). In this paper, we measured subscriber network of KT(Korea Telecom) to analyze P2P traffic characteristics. We show flow characteristics of measured traffic. We also estimate Hurst parameter of P2P traffic and compare self-similarity with web traffic. Analysis results indicate that P2P traffic is much bustier than web traffic and makes both upstream traffic and downstream traffic be symmetric. To predict parameters related QoS such as packet loss and delays we model P2P traffic using two self-similar traffic models and predict both loss probability and mm delay then compare their accuracies. With simulation we show that the self-similar traffic models we derive predict the performance of P2P traffic accurately and thus when we design a network or evaluate its performance, we can use the P2P traffic model as reference input traffic.

• Journal of Periodontal and Implant Science
• /
• v.27 no.2
• /
• pp.425-441
• /
• 1997

The neuropeptide substance P(SP) has been implicated in the mediation of inflammation and immune-mediated disease such as arthritis. Recently, it was reported that SP was markedly increased around the blood vessels in inflamed gingiva as well as in close association with the inflammatory cell infiltrate. These results support that SP may contribute to the pathophysiology of neuronal inflammation in human periodontal tissues. SP may regulate inflammatory/immune responses by stimulating the proliferation of human T cells, differentiation and antibody-secreting potential of B cells, macrophage respiratory burst, connective tissue proliferation, and the secretion of cytokines from monocytes and T cells. Here, I studied potential role of SP as a costimulatory chemical signal in inflammatory/immune responses, by determining the released proinflammatory cytokines such as $MIP-1{\alpha}$, $IL-1{\beta}$, and IL-6 from culture supernatants of homogeneous immune cell lines. Serum free cell supernatants were concentrated with TCA precipitation, fractionated with SDS-PAGE, and subjected into western blot analysis. Among 15 cell lines tested, macrophage/monocyte cell line RAW264.7 and WRl9m.1 showed the highest level of induction of $MIP-1{\alpha}$ when stimulated with LPS. Discrete IL-6 bands with multiple forms of molecular mass were detected from supernatants of B cell lines A20(32kDa), Daudi(32, 35kDa), and SKW6.4(29kDa), which were expressed constitutively. $IL-1{\beta}$ could not be detected by the method of western blot analysis from supernatants of all cell lines tested except RAW264.7, WRl9m.1, and erythroid cell line K562 which showed the least amount of $IL-{\beta}$ secretion. SP $10^{-9}M$ with suboptimal dose of LPS treatment showed synergistic induction of $MIP-1{\alpha}$ release from RAW264.7 or WR19m.1, and also IL-6 release from A20, but this synergism is not the case in costimulation of RAW264.7 or WRl9m.1 with SP $10^{-9}M$ and TPA. Although treatment of T cell line CTLL-R8 with SP $10^{-7}M$ or PHA+TPA induced modest level of $MIP-1{\alpha}$ secretion, synergism was not observed when they are applied together. These findings all together suggest the possibility of a regulatory role of SP in inflammatory/immune reaction through differential modulation of bioactivities of other chemical cosignals.

• Journal of Bio-Environment Control
• /
• v.19 no.3
• /
• pp.147-152
• /
• 2010

Poor fruit set during winter period is one of the biggest problem in plastic tunnel watermelon cultivation. Hand pollination is inevitable to maximize fruit set of the winter watermelon. Productivity and viability of pollen grain and organic solvents for pollen storage were investigated. All cultivars produced more than 10 mg/flower except for 'Kumchun' cultivar. Pollen amount per flower were 13.8 mg in 'Bok' and 12.1 mg in 'Speedkul'. Germination rate of pollen grains incubated at $30^{\circ}C$ right after soaking in pentane solvent were 76% in 'Kumchun' as the lowest and 92% in 'Apollokul' as the highest. The pollen of 'Bok' showed the highest germination rate by 75% after a 15-day storage in pentane. All cultivars showed their pollen germination rate below 25% after a 24-day storage. Among the cuitivars, speed of pollen tube growth in vitro were relatively lower in 'Kumchun' and 'Sambokkul' by below $50\;{\mu}m/hr$. Pollen tube of these cultivars tended to burst during its elongation on the medium. Pollen stored 24 hrs in organic solvents showed 45, 39, 34, 23, and 19% of germination in pentane, ethyl ether, n-hexane, ethyl acetate, and acetone, respectively. Compared with light condition, pollen viability was higher in darkness during pollen storage in organic solvents. Pollen grain was susceptible to the organic solvent. The viability of pollen grains seems to be influenced greatly by duration of soaking pollen in organic solvent and the polarity of solvents. Organic solvent damages surface of pollen grain and extent of damage was varied by the solvents.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.19 no.6
• /
• pp.147-153
• /
• 2018

PLGA microcapsule particles encapsulating BSA aqueous solutions were prepared using a water-in-oil-in-water emulsion method. The morphology, particle size, BSA encapsulating efficiency, and in-vitro release test were also studied using the microcapsule particles. In the outer aqueous phase, an emulsifier, e.g., PVA, was replaced with metal salts for surface solidification. Scanning electron microscopy (SEM) showed that the microcapsule particles had smooth surfaces and were between $1{\mu}m$ and $7{\mu}m$ in size. The microcapsule particle morphology was affected directly by the ratio between the polymer solution and inner aqueous solution, and composition of the outer aqueous solution. The factors also partially affected the BSA encapsulation efficiencies and in-vitro release rates. All the microcapsule particles showed an initial burst release through the in-vitro release test. On the other hand, the particles also showed a relatively long release period. Metal salts could be good choices to replace the emulsifier to solidify the microcapsule particle surfaces.

• The Journal of the Acoustical Society of Korea
• /
• v.35 no.4
• /
• pp.295-302
• /
• 2016

Underwater acoustic communication channel is often defined as a multipath fading channel since the multipath arrivals from various paths interfere with each other and cause frequency dependent constructive or destructive interference in received signals. Therefore signal-to-noise ratio (SNR) of received signal fluctuates as a function of frequency. In addition, sea surface fluctuation induces frequency dependent time variant signal fading due to coherent component variation of surface bounce path. The frequency shift keying (FSK) system is known to be less sensitive and more robust under these interference and fading, and M-ary frequency shift keying (MFSK) system is adopted to increase a data rate. In this study, a bit error rate (BER) of 4 channels 4FSK system are examined in shallow sea multipath channel. Experimental results show that RS code reduces efficiently the BER of 4FSK system since frequency dependent time-varying fading is characterized to give burst errors. The BER of a different data rate or different source-to-receiver range depends on not only the channel coherent bandwidth but also frequency dependent multipath fading.

• Journal of Korean Academy of Nursing
• /
• v.29 no.3
• /
• pp.605-613
• /
• 1999

The main purposes of this study were to determine the time interval between the onset of symptoms of myocardial infarction and treatment-seeking time and to identify the factors related to the interval time. This study used a retrospective design. The sample consisted of 45 patients aged over 30 who were diagnosed with an acute myocardial infarction at two large university affiliated medical center from September 1, 1997 to June 30, 1998. Data was collected by using questionnaries, which included demographic data, permonitory clinical signs and symtoms of myocardial infarction, and a measure of the severity of the signs and symptoms. Also semi-structured interviews and chart reviews were used to obtain information related to treatment-seeking time. The results of this study are summarized as follows ; 1. The most frequent premonitory clinical symptom was chest pain(92.9%), the second, was perspiration(81.0%), and the next were nausea(40.5%) and dyspnea(38.1%). Thirty two patients reported having more than four premonitory signs and symtoms. Patients described the characteristics of chest pain as “somethings very heavy pressing down”(26.2%), “felt like my chest would burst”(24.4%), or “sharp pain”(16.7%), Over 95% of the sample reported having chest pain. 2. Twenty two (52.4%) patients reported to have “very severe” premonitory pain. 3. The mean time interval between the onset of signs and symptoms and the arrival at the medical center was 6.39$\pm$10.80 hours in 42 samples, the mean time from the onset to arrival at a local hospital was 3.27$\pm$5.39 hours and for transfer from a local hospital to the medical center was 4.75$\pm$9.87 hours in patients who had arrived at medical center via local hospital. 4. The severity of premonitory signs and symptoms did not differ significantly according to existence of premonitory signs and symptoms. 5. There was no significant relationship between treatment-seeking time and age, gender, marital status, economic status, occupation, or residence. But education had significant relationship(r＝－0.51, p＝0.01). Analysis of difference of the time interval according to the premonitory signs and symptoms showed that the time was shorter in patients who experienced nausea or dyspnea(U＝115.50, p＝0.01, U＝132.00, p＝0.04), however the severity of premonitory signs and symptoms did not have statistical significance.

• Journal of Korea Multimedia Society
• /
• v.13 no.5
• /
• pp.740-753
• /
• 2010

Performance of TCP can be severely degraded in WLP-based Mobile IP wireless networks where packet loss not related to network congestion occurs frequently during WLP-based inter-subnetwork handoff by user mobility. To resolve such a problem in the networks using WLP-based Mobile IP, the packet buffering method recovering seamlessly the packets dropped due to user mobility has been proposed. The packet buffering method at a bridge station recovers those packets dropped during handoff by forwarding buffered packets at the old bridge station to the WLP device. But, when the WLP device moves to a congested bridge station in a new WLP foreign subnetwork, those buffered packets forwarded by the old bridge station are dropped and TCP transmission performance of a WLP device in the congested bridge station degrades due to increased congestion by those forwarded burst packets. In this paper, a PBM(Packet Bridge Marker) is proposed for preventing buffered out-of-profile(OUT) packets from reducing the throughput of in-profile(IN) packets of an Assured Service WLP device. From this operation, the packet losses of buffered OUT packets are avoided and the throughput of IN and Total packets of an AS WLP device are increased.