On Golay sequences Kounias, S.; Koukouvinos, C.; Sotirakoglou, K.
Discrete mathematics,
11/1991, Volume:
92, Issue:
1
Journal Article
Peer reviewed
Open access
Golay sequences are two binary (+1, -1) sequences with nonperiodic autocorrelation function zero. These sequences have a wide range of applications in constructing orthogonal designs and Hadamard ...matrices, in coding theory, in multislit spectrometry and in surface acoustic wave devices.
In this paper we develop an algorithm for constructing such sequences. We prove that Golay sequences of length
n = 2 · 7
2
t
do not exist and we give new proofs of some known results. In particular we show there are no Golay sequences of length 98. We conjecture that there are no Golay sequences of length 2 ·
q
2
t
where
q is not the sum of two integer squares.
BACKGROUNDThe Hemiconvulsions-Hemiplegia-Epilepsy (HHE) syndrome is currently regarded as an extremely rare condition. The etiological and pathophysiological mechanisms underlying this medical rarity ...as well as the optimal therapeutic approaches remain poorly defined and understood. We present the clinical, radiological and electroencephalography (EEG) findings of a patient with the HHE syndrome and describe the response of the continuously present epileptiform abnormalities to transcranial magnetic stimulation (TMS). CASE DESCRIPTIONA 33-year old male patient was referred to our department for investigation and management of intractable epilepsy. His seizures began at the age of three months when, during the course of a common febrile illness, he developed repetitive clonic seizures involving the left upper and lower limbs, followed by permanent left hemiplegia. After extensive investigations, he was diagnosed with "idiopathic" HHE syndrome. Currently, he suffers from left hemiplegia, severe intellectual impairment Intelligence Quotient (IQ) <30 and asymmetric, bilateral tonic seizures occurring 1-3 times daily despite treatment with valproate, topiramate, lamotrigine, rufinamide, and perampanel. Brain magnetic resonance imaging revealed atrophy of the right hemisphere and serial EEGs disclosed continuous sharp waves, the generators of which were localized by electrical source imaging (ESI) to two distinct sources within the right hemisphere. Repetitive TMS 210 stimuli of 1 Hz at 100 % corticomotor threshold applied with a circular coil over the generators of epileptic discharges (EDs) resulted in a statistically significant decrease of ED counts compared to sham stimulation and the post-verum TMS period. CONCLUSIONWe present the clinical-laboratory profile and the long-term follow up of a patient with the HHE syndrome. Further, we describe the effects of TMS on EDs. The latter observation raises the possibility that TMS-EEG may be used in select cases with intractable epilepsy as a surrogate marker of responsiveness to more invasive modalities (i.e., cortical stimulation). HIPPOKRATIA 2017, 21(2): 101-104.
On Base and Turyn Sequences Koukouvinos, C.; Kounias, S.; Sotirakoglou, K.
Mathematics of computation,
10/1990, Volume:
55, Issue:
192
Journal Article
Peer reviewed
Open access
Base sequences of lengths $n + 1, n + 1, n, n$ are constructed for all decompositions of $4n + 2$ into four squares for $n = 19, \ldots, 24$. The construction is achieved through an algorithm which ...is also presented. It is proved through an exhaustive search that Turyn sequences do not exist for $n = 18, \ldots, 27$; since Turyn sequences cannot exist for $n = 28$ or 29, the first unsettled case is $n = 30$.
Lower and upper bounds of degree m for the probability of the union of n not necessarily exchangeable events are established. These bounds may be constructed to improve the Bonferroni and the ...Sobel–Uppuluri bounds. An application to equi-correlated multivariate normal distribution is given.
Teleme cheese was made from ovine, caprine and bovine milk with thermophilic (Streptococcus thermophilus, Lactobacillus delbrueckii subsp. bulgaricus), mesophilic (Lactococcus lactis subsp. lactis, ...Lactococcus lactis subsp. cremoris) and mixed thermophilic-mesophilic (1:1) cultures. Nine lots of cheese each time (five repetitions) were made in order to study the proteolysis of cheeses during ripening and storage up to 6 months. All cheeses showed similar profiles of proteolysis. However, the rate of proteolysis was different. The thermophilic and the mesophilic cultures resulted in cheeses with the highest and the lowest degree of proteolysis, respectively. Proteolysis was of a descending order in cheeses made from sheep's, goat's and cow's milk when estimated on the basis of nitrogenous fractions (total nitrogen, water soluble nitrogen, nitrogen soluble in 5% phosphotungstic acid and nitrogen soluble in 12% trichloroacetic acid), whereas it was highest in cow's milk cheeses and lowest in goat's milk cheeses when estimated on the basis of electrophoresis and RP-HPLC. Multivariate analysis of the data revealed that cheeses could be more correctly clustered by the type of milk or culture than by the stage of ripening.
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