• Bulletin of the Korean Mathematical Society
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• v.52 no.4
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• pp.1097-1105
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• 2015

The concept of tensor analogues of right 2-Engel elements in groups were defined and studied by Biddle and Kappe [1] and Moravec [9]. Using the automorphisms of a given group G, we introduce the notion of tensor analogue of 2-auto Engel elements in G and investigate their properties. Also the concept of $2_{\otimes}$-auto Engel groups is introduced and we prove that if G is a $2_{\otimes}$-auto Engel group, then $G{\otimes}$ Aut(G) is abelian. Finally, we construct a non-abelian 2-auto-Engel group G so that its non-abelian tensor product by Aut(G) is abelian.

• Communications of the Korean Mathematical Society
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• v.35 no.4
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• pp.1087-1093
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• 2020

The aim of this paper is to show that every Engel quasinormal subgroups of the unit group of a division ring with uncountable center is central.

• Bulletin of the Korean Mathematical Society
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• v.53 no.3
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• pp.657-665
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• 2016

A general notion of ${\chi}$-transitive groups was introduced by C. Delizia et al. in [6], where ${\chi}$ is a class of groups. In [5], Ciobanu, Fine and Rosenberger studied the relationship among the notions of conjugately separated abelian, commutative transitive and fully residually ${\chi}$-groups. In this article we study the concept of 2-Engel transitive groups and among other results, its relationship with conjugately separated 2-Engel and fully residually ${\chi}$-groups are established. We also introduce the notion of 2-Engelizer of the element x in G and denote the set of all 2-Engelizers in G by $E^2(G)$. Then we construct the possible values of ${\mid}E^2(G){\mid}$.

• Journal of the Korean Home Economics Association
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• v.32 no.2
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• pp.1-16
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• 1994

This paper analysis the structure of Housing Consumption Expenditure of urban salary and wage-earners' households from 1982 to 1992 by employing Time-series. Data was based on " Annual report on the Family Income and Expenditure Survey" of the National Bureau of Statistic Planning Board, Republic of Korea. Percentile marginal-propensity to consume(MPC) and income elasticity of consumption expenditure are estimated by their socio-economic and demographic variables. The results are as follows: 1. The proportion of the expenditure for furniture and utensils and house mending has increased with the increase of income in urban salary and wage-earners' households, while fuel light and water charges and rents paid has decreased. 2.1) Engel Function by income group; MPC associated with rents paid and fuel light and water charges is higher in the lower income group than in the rest. The income elasticity estimates in rents paid and fuel light and water charges is less than 1 in all group while larger than 1 in furniture and utensils and house mending. 2) Engel Function by occupation of household head; The highest MPC in rents paid is associated with the sales profession. The income elasticity of fuel light and water charge is found be inelastic. The groups other than the sales group show irregular MPC. 3) Engel Function by family size; MPC in house mending and fuel light and water charge is increased while is decreased in rents paid in accordance with family size. The income elasticity of rents paid and fuel light and water charge is less than 1 in all groups while that of house mending and furniture and utensils is larger than 1. 4) Engel Function by age of housegold head; MPC in rents paid is decreased according to the age of housefold head. The income elasticity of rents paid and fuel light and water charge is less than 1 in all group while it is larger than 1.

• The Journal of Health Technology Assessment
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• v.6 no.2
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• pp.142-147
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• 2018

Objectives: The purpose of this study is to evaluate the safety and effectiveness of Robot-Assisted Brain Stereotactic Surgery with a systematic review. Methods: Electronic literature was searched using KoreaMed, Ovid-MEDLINE, Ovid-EMBASE, and Cochrane Library on 6th April 2017. Two authors screened 1218 citations. Duplicated articles of 456 excluded, the remaining 762 articles were reviewed with title and abstract. Results: A total of 8 studies were selected in this review. The device used in all studies was $ROSA^{TM}$. In one cohort study comparing the intervention ($ROSA^{TM}$) with the control (conventional stereotactic surgery), hematoma was reported no significant difference between groups. In six descriptive studies, one study reported hematoma 10% (10/100) and temporary nerve impairment 6% (6/100) using the ROSA; while five descriptive study did not report any complications. In one cohort, the localization precision were 1.2 mm in the intervention group and 1.1 mm in the control group; the localization success rate as 78.2% in the intervention group and 76.2% in the control group in one cohort; and the average time for surgery as 130 min for the intervention group and 352 min for the control group in one cohort. Four studies reported the localization success rate as 100%; two out of three articles reported the overall time for surgery as 56 min and 90 min, while one article reported the time as less than one hour in 50% of patients (50/100); two articles reported in epilepsy patients, the condition after the surgery was Engel level I in 66.2%, 75% patients, Engel level II-III in 25%, 26.5% patients, and Engel level 4 in 7.3% patients. Conclusion: Robot-Assisted Brain Stereotactic Surgery is a safe and accurate technique that can significantly reduce the time for the brain stereotactic surgery. However, further studies are needed to generalize the results.

• Bulletin of the Korean Mathematical Society
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• v.51 no.4
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• pp.923-931
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• 2014

Let x be an element of a group G and be an automorphism of G. Then for a positive integer n, the autocommutator $[x,_n{\alpha}]$ is defined inductively by $[x,{\alpha}]=x^{-1}x^{\alpha}=x^{-1}{\alpha}(x)$ and $[x,_{n+1}{\alpha}]=[[x,_n{\alpha}],{\alpha}]$. We call the group G to be n-auto-Engel if $[x,_n{\alpha}]=[{\alpha},_nx]=1$ for all $x{\in}G$ and every ${\alpha}{\in}Aut(G)$, where $[{\alpha},x]=[x,{\alpha}]^{-1}$. Also, for any integer $n{\neq}0$, 1, a group G is called an n-auto-Bell group when $[x^n,{\alpha}]=[x,{\alpha}^n]$ for every $x{\in}G$ and each ${\alpha}{\in}Aut(G)$. In this paper, we investigate the properties of such groups and show that if G is an n-auto-Bell group, then the factor group $G/L_3(G)$ has finite exponent dividing 2n(n-1), where $L_3(G)$ is the third term of the upper autocentral series of G. Also, we give some examples and results about n-auto-Bell abelian groups.

• Journal of Korean Neurosurgical Society
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• v.65 no.3
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• pp.415-421
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• 2022

Objective : Seizure recurrence after the first-ever seizure in patients with a supratentorial cerebral cavernous malformation (CCM) is almost certain, so the diagnosis and treatment of epilepsy is justified. The optimal method of management of these patients is still a matter of debate. The aim of our study was to identify factors associated with postoperative seizure control and assess the surgical morbidity rate. Methods : We retrospectively analysed 45 consecutive patients with a supratentorial CCM and symptomatic epilepsy in a single centre. Pre- and postoperative epidemiological data, seizure-related patient histories, neuroimaging results, surgery details and outcomes were obtained from hospital medical records. Seizure outcomes were assessed at least 12 months after surgery. Results : Thirty-five patients (77.8%) were seizure free at the long-term follow-up (Engel class I); six (13,3%) had rare, nocturnal seizures (Engel class II); and four (8.9%) showed meaningful improvement (Engel class III). In 15 patients (33%) in the Engel I group; it was possible to discontinue antiepileptic medication. Although there was not statistical significance, our results suggest that patients can benefit from early surgery. No deaths occurred in our study, and mild postoperative neurologic deficits were observed in two patients (4%) at the long-term follow-up. Conclusion : Surgical resection of CCMs should be considered in all patients with a supratentorial malformation and epilepsy due to the favourable surgical results in terms of the epileptic seizure control rate and low postoperative morbidity risk, despite the use of different predictors for the seizure outcome.

• Journal of Korean Neurosurgical Society
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• v.29 no.12
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• pp.1650-1656
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• 2000

Objective : Little consensus exists concerning which temporal lobe structures need to be resected or how much resection should be done during hippocampal resection. The purpose of this study is to identify whether the extent of hippocampal resection influences seizure after anterior temporal lobectomy. Materials and Methods : The extent of hippocampal resection was assessed in 96 patients who underwent temporal lobectomy for medically intractable complex partial seizures originating from a unilateral seizure focus in the anteromesial temporal lobe. Patients who had structural lesion were excluded from the study. Postoperative magnetic resonance imaging in the coronal and saggital planes were used to quantify the extent of the hippocampal and lateral cortical resection. The patients were divided into two groups. Patients who underwent hippocampal resection to the level of the cerebral peduncle were included in the partial resection group, and those who had resection to the level of the colliculus were assigned to total resection group. Seizure outcomes were defined according to the Engel classification and compared between the two groups. Neuropsychologic outcomes in the selected cases were reviewed. Results : The over-all seizure-free outcome(Engel classification 1) was accomplished in 75%(72/96) of the patients (mean duration of follow-up, 36.8 months). The total hippocampectomy group had a statistically superior seizure outcome than the partial hippocampectomy group(87.3% versus 58.5% seizure-free, p-value=0.001). Also, younger patients had a more favorable outcome. Other variables such as laterality, the extent of lateral cortical resection, age at onset and gender were not significant. The pre- and postoperative memory functions were evaluated in 24 patients. A worse postoperative memory outcome was associated with partial hippocampectomy. However this was not acceptable due to a former bias. Conclusion : The result of this study conforms that aggressive hippocampectomy resulted in a better seizure outcome.

• Journal of the Korean Society of Clothing and Textiles
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• v.13 no.3 s.31
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• pp.223-241
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• 1989

As a preliminary work for the clothing conformity study, Its theoretical backgrounds were reviewed. In the view of convertibility into clothing conformity, two prevailing conformity types were studied. One is normative-social influence and informational-social influence classified by Deutsch and Gerald. And the other is Kelman's classification which includes compliance, identification and internalization. Reference group, as an object of conformity, was studied. In addition to Engel and Blackwell' s and Assael's classification, the reference groups which were revealed in the studies of consumer behavior and clothing behavior were reviewed. The factors were reviewed which influence conformity and clothing conformity. They were product factor, group factor, situational factor and individual factor.

• Journal of the Korean Society of Food Culture
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• v.16 no.2
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• pp.99-108
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• 2001

A survey was conducted to assess the food-purchase behavior of 197 Taejon full time housewives 30 to 49 years of age. Food purchase was assessed using a questionnaire and the resulting data were analyzed using SPSS programs. Demographic data revealed that most of the households have three to five family members and that the Engel Indices of the participating households were mostly between 10 and 30%. Noticeable results of the food purchase assessment are as follows. In the grain and grain products items, the low-education group purchased more rice and barley than the high-education group, whereas the high-education group purchased more glutinous rice, brown rice, bread, macaronis and spaghetti than the low-education group. In the vegetable items, the low-education group purchased more Chinese cabbage and radish than the high-education group, while the high-education group purchased more head lettuce, broccoli and sweet pepper than the low-education group. In the meat items, the beef purchase was higher in the high-education than in the low-education group, while the pork purchase was higher in the low-education than in the high-education group . In the processed meat items, ham was the most favorite purchase item regardless of the education level. In the fish and shellfish items, Pacific cod and Alaska pollack were purchased more in the low-education than in the high-education group, and salmon and dried icefish strip were purchased more in the high-education than in the low-education group. No items in fruit group showed significant differences in the purchase amount between the low-education and the high-education group although the latter purchased more imported-fruits such as melons, kiwis, grapefruits, and oranges. Dairy products such as milk, cheese and butter were purchased more in the high-education than in the low-education group. It was also found that both the number of food items and the consumption of foods coming from animals were higher in the high-education than in the low-education group.