• The Journal of the Korea institute of electronic communication sciences
• /
• v.8 no.4
• /
• pp.611-617
• /
• 2013

Although tuberculosis can be recovered if patients take medicine consistently, Korea shows significantly high rate in terms of incident rate and death rate of the tuberculosis patients. Considering such a situation, this paper has developed a smart pillbox that facilitates for patients requiring a long-term administration to take medicine in a regular and consistent manner. The developed smart pillbox is equipped with a load cell that can measure the weight in unit of 0.1g so that it can determine whether or not the medicine is dispensed out of itself. In addition, a software has been developed to determine the status of patient's taking medicine based on the measurement result.

• Journal of applied mathematics & informatics
• /
• v.31 no.5_6
• /
• pp.747-767
• /
• 2013

In this paper we have constructed a mathematical model of alcohol abuse which consists of four compartments corresponding to four population classes, namely, moderate and occasional drinkers, heavy drinkers, drinkers in treatment and temporarily recovered class. Basic reproduction number $R_0$ has been determined and sensitivity analysis of $R_0$ indicates that ${\beta}1$ (the transmission coefficient from moderate and occasional drinker to heavy drinker) is the most useful parameter for preventing drinking habit. Stability analysis of the model is made using the basic reproduction number. The model is locally asymptotically stable at disease free or problem free equilibrium (DFE) $E_0$ when $R_0<1$. It is found that, when $R_0=1$, a backward bifurcation can occur and when $R_0>1$, the endemic equilibrium $E^*$ becomes stable. Further analysis gives the global asymptotic stability of DFE under some conditions. Our important analytical findings are illustrated through computer simulation. Epidemiological implications of our analytical findings are addressed critically.

• Journal of Sensor Science and Technology
• /
• v.27 no.3
• /
• pp.175-181
• /
• 2018

In this paper, we introduce a new dimming control method in a visible light communication (VLC) system wherein byteinversion is adopted for flicker-free transmission. In the VLC transmitter, the original and the inverted data were sent sequentially and the remnant time in one period was used for the dimming control of the LED light. In the VLC receiver, only the original data was recovered using the gating signal whose width was the same as the length of the original data. In our experiments, the dimming control ranges were measured to be 22%-53%, 11%-76%, and 5%-88% of the CW LED light when the data rates were 9.6, 19.2, and 38.4 kbps, respectively. In this system, we used a 240-Hz sync pulse whose period was 4.16 ms, which was shorter than the maximum flickering time period of 5 ms that is generally considered to be safe. This configuration is very simple and useful in constructing indoor wireless sensor networks using the flicker-free LED lamps with dimming control capability.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.6 no.8
• /
• pp.1946-1963
• /
• 2012

Hummingbird is a lightweight encryption and message authentication primitive published in RISC'09 and WLC'10. In FSE'11, Markku-Juhani O.Saarinen presented a differential divide-and-conquer method which has complexity upper bounded by $2^{64}$ operations and requires processing of few megabytes of chosen messages under two related nonces (IVs). The improved version, Hummingbird-2, was presented in RFIDSec 2011. Based on the idea of differential collision, this paper discovers some weaknesses of the round function WD16. Combining with the simple key loading algorithm, a related-key chosen-IV attack which can recover the full secret key is proposed. Under 15 pairs of related keys, the 128 bit initial key can be recovered, requiring $2^{27}$ chosen IV and the computational complexity is $O(2^{27})$. In average, the attack needs several minutes to recover the full 128-bit secret key on a PC. The experimental result corroborates our attack. The result shows that the Hummingbird-2 cipher can't resist related key attack.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.4 no.3
• /
• pp.400-410
• /
• 2010

In an identity-based threshold broadcast encryption (IDTHBE) scheme, a broadcaster chooses a set of n recipients and a threshold value t, and the plaintext can be recovered only if at least t receivers cooperate. IDTHBE scheme is different from the standard threshold public key encryption schemes, where the set of receivers and the threshold value are decided from the beginning. This kind of scheme has wide applications in ad hoc networks. Previously proposed IDTHBE schemes have ciphertexts which contain at least n elements. In addition, the security of theses schemes relies on the random oracles. In this paper, we introduce two new constructions of IDTHBE for ad hoc networks. Our first scheme achieves S-size private keys while the modified scheme achieves constant size private keys. Both schemes achieve approximately (n-t)-size ciphertexts. Furthermore, we also show that they are provablesecurity under the decision bilinear Diffie-Hellman Exponent (BDHE) assumption in the standard model.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.10 no.9
• /
• pp.4442-4466
• /
• 2016

This paper proposes a privacy-preserving aggregation scheme based on the designed P-Gene (PAPG) for sensor networks. The P-Gene is constructed using the designed erasable data-hiding technique. In this P-Gene, each sensory data item may be hidden by the collecting sensor node, thereby protecting the privacy of this data item. Thereafter, the hidden data can be directly reported to the cluster head that aggregates the data. The aggregation result can then be recovered from the hidden data in the cluster head. The designed P-Genes can protect the privacy of each data item without additional data exchange or encryption. Given the flexible generation of the P-Genes, the proposed PAPG scheme adapts to dynamically changing reporting nodes. Apart from its favorable resistance to data loss, the extensive analyses and simulations demonstrate how the PAPG scheme efficiently preserves privacy while consuming less communication and computational overheads.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.13 no.11
• /
• pp.882-889
• /
• 2003

This paper presents the method for structure borne noise analysis of a flexible body in multibody system. The proposed method is the superposition method using the flexible multibody dynamic analysis and the finite element one. This method is executed in 3 steps. In the 1st step, time dependent quantities such as dynamic loads, modal coordinates and gross body motion of the flexible body are calculated through a flexible multibody dynamic analysis. And frequency response functions of those time dependent quantities are computed through Fourier transforms. In the 2nd step, acoustic pressure coefficients are obtained through structure-acoustic coupling analyses by the finite element method. In the final step, frequency responses of acoustic pressure at the acoustic nodes are recovered through linear superposition of frequency response functions with acoustic pressure coefficients. The accuracy of the proposed method is verified in the numerical example of a simple car model.

• The Journal of Internal Korean Medicine
• /
• v.17 no.1
• /
• pp.278-289
• /
• 1996

This paper aims to probe the effect of Rosa rugosa, Thunbergii which streptozotocin induced hyperglycemic rats was examined by glucose contents, body weight, kidney weight and histological observation. The results obtained were as follows: 1. The glucose level is decreased in the adminstered group of the Rosa rugosa compared with control group. These effects are in order named root group, stem group and leaf group group. BUN is increased fold of 1.52 in the control group compared with normal group, but the administered group of Rosa rugosa are decreased., in order named leaf group, root group and stem group. 2. The kidney hypertrophy to body weight is the higest in the control group compared with the other group in rats, and glucose contents are in order named stem group, leaf group and root group. 3. The loss of body weight is the highest in the control group, and the loss is in order named stem group, leaf group and root group in rats. 4. In histological observations, pancreatic pancreatic islets of control group shows disrupted or condensed nuclei, and the intercellular space between acini are enlarged. In the experimental group, histological damages of the acini and pancreatic islet are recovered compared with control group. Thes results suggest that the extracts of Rosa rugosa are effected to diabetes mellitus, root extract correlated with the function of kidney, and leaf extract is decreased plasma glucose.

• Journal of the Korean Society for Precision Engineering
• /
• v.30 no.5
• /
• pp.529-536
• /
• 2013

Most serious stroke patients have the paralysis on their wrists, and can't use their hands freely. But their wrists can be recovered by rehabilitation exercises. Recently, professional rehabilitation therapeutists help stroke patients exercise their wrists in hospital. But it is difficult for them to rehabilitate their wrists, because the therapeutists are much less than stroke patients in number. Therefore, the wrist twist-exercise rehabilitation robot that can measure the twist force of the patients' wrists is needed and developed. In this paper, the six-axis force/moment sensor was designed appropriately for the robot. As a test result, the interference error of the six-axis force/moment sensor was less than 0.85%. It is thought that the sensor can be used to measure the wrist twist force of the patient.

• Korean Journal of Veterinary Research
• /
• v.50 no.4
• /
• pp.331-333
• /
• 2010

Moribund albino catfish, Clarias sp., displayed from an indoor private commercial aquarium were submitted in the laboratory for diagnostic examination. Dense culture of bacteria was recovered from the kidney and was characterized using Vitek System 2 and showed 98% probability to Aeromonas (A.) hydrophila. PCR result showed positive using A. hydrophila extracellular hemolysin gene ahh1 (130 bp) and aerolysin gene aerA (309 bp). The 16S rRNA gene was identical and exhibited 97% sequence similarity with the other known isolates of A. hydrophila available in the GenBank. In this paper, we reported the isolation and molecular detection of A. hydrophila from an albino catfish.