美國移住者의 階層構造와 移住動機

김해동 漢陽大學校 大學院 1987 국내석사

접지면 공진을 응용한 2.4 GHz 대역의 FR4 소형 칩 안테나

김해동 금오공과대학교 산업대학원 2009 국내석사

Compact FR4 chip antenna based upon the characteristic of ground resonance is proposed for the purpose of reducing it to the antenna size which is compatible with the size of the seramic chip antenna. The operating frequency band of the proposed antenna is 2.4GHz ISM band. Therefore it is expected that the proposed antenna can be usefully applied to the low cost antenna of wireless networking systems such as Bluetooth, WLN(Wireless LAN) and Zig-bee. The proposed antenna consists of the ground patch with a slit as main radiator and FR4 chip antenna. The proposed antenna is implemented on the square ground plane of dimension of 45 x 45mm2, while the 3D size of FR4 chip antenna is 7.2 x 2.1 x 1.2mm3. The impedance bandwidth of it is 2.4 ~ 2.5GHz for VSWR < 2. While the average gain and efficiency of it are -2.8 ~ 0.8dBi and 52.1 ~ 83.1% respectively over the operating frequency band. And the radiation pattern of the proposed antenna is omnidirectional and similar to the dipole antenna over the whole operating frequency band.

Upwind 수치기법을 이용한 무딘물체 주위의 극초음속 유동장 해석

김해동 서울대학교 대학원 1991 국내석사

8주간의 유산소성 운동이 지적장애인의 건강체력에 미치는 영향

김해동 가천대학교 2018 국내석사

The purpose of this study was to investigate the effect of aerobic exercise on fitness, cardiovascular endurance, flexibility, strength and muscle endurance for 8 weeks. The subjects of this study were aerobic exercise(bicycle) exercise for 18 men with intellectual disabilities in Seoul. Exercise programs exercise three times a week for 50 minutes, warm up five minutes before exercise and exercise for five minutes for 60 minutes. In this study, five components of health fitness are 'body composition, cardiovascular endurance, flexibility, muscle endurance and strength'. Body composition, body weight, skeletal muscle mass, body mass, and body fat percentage were measured by Inbody 270. The Harvard step test was performed using a wireless heart rate monitor(Porla) for cardiac endurance. Flexibility was measured by measuring the left anterior cruciate twice, and good records were selected. Muscle endurance was one minute for sit-ups. Muscle strength was measured twice using force gauge. A paired t-test was used to verify the pre- and post-effects of each variables. The statistical significance level(a) was set to .05. The results of the study are as follows. First, the 8-weeks of aerobic exercise, weight, fat and body fat percentage of subjects were significantly decreased and skeletal muscle mass was significantly increased. Second, the 8-week aerobic exercise, cardiovascular endurance of the intellectual disability was statistically significantly increased. Third, the 8-week aerobic exercise increased the flexibility of the mentally handicapped statistically significantly. Fourth, the 8-week aerobic exercise significantly increased the muscle endurance of the mentally handicapped. Fifth, the aerobic exercise for 8-weeks did not show statistical significance on the right side strength (grip strength) of the intellectual disabled persons and statistically not on the left side strength (grip strength). This study was conducted to investigate the effect of aerobic exercise on health fitness for people with intellectual disabilities. There were significant differences in body composition, cardiovascular endurance, flexibility, muscle endurance, and muscle strength (grip strength). Based on these data, it is necessary to study the improvement of the physical fitness and the physical activity level as well as the physical fitness through the combined exercise (aerobic exercise, whole body strength exercise). 이 연구의 목적은 8주간의 유산소성 운동이 지적장애인의 건강체력(신체구성, 심폐지구력, 유연성, 근력, 근지구력)에 미치는 영향에 대해 알아보는데 목적이 있었다. 연구의 대상자는 서울특별시에 거주하는 지적장애인 18명을 대상으로 8주간의 유산소성 운동(자전거)를 실시하였으며, 주3회, 매회 50분간 진행하였고 운동 전 warm-up 5분, 운동 후 cool-down 5분으로 총 60분으로 진행하였다. 이 연구의 5가지 건강체력 ‘신체구성, 심폐지구력, 유연성, 근지구력, 근력’을 측정하였고, 이를 측정하기 위한 장비는 다음과 같다. 신체조성은 Inbody270으로 실시 체중, 골격근량, 체지방량, 체지방률을 측정하였다. 심폐지구력 측정으로는 무선심박수측정기(Porla)를 통해 Harvard step test를 진행하였다. 유연성은 좌전굴로 2회씩 측정하여 좋은 기록으로 선정하였고, 근지구력으로는 1분 동안 윗몸일으키기를 실시하였고 근력은 악력측정기를 통해 2회 측정하여 좋은 기록을 선정하였다. 각 요인에 대한 사전·후 효과를 검증하기 위해 종속 t 검증(paired t-test)을 하였으며 통계학적 유의수준(a)은 .05로 설정하였다. 연구의 결과는 다음과 같다. 첫째, 8주간의 유산소성 운동이 지적장애인들의 신체구성 요소 중 체중, 체지방량, 체지방률은 통계적으로 유의하게 감소하였고, 골격근량에서는 유의하게 증가하였다. 둘째, 8주간의 유산소성 운동이 지적장애인들의 심폐지구력이 통계적으로 유의하게 증가하였다. 셋째, 8주간의 유산소성 운동이 지적장애인들의 유연성이 통계적으로 유의하게 증가하였다. 넷째, 8주간의 유산소성 운동이 지적장애인들의 근지구력이 통계적으로 유의하게 증가하였다. 다섯째, 8주간의 유산소성 운동이 지적장애인들의 우측근력(악력)과 좌측근력(악력)은 통계적으로 유의함이 나타나지 않았다. 위의 연구결과를 토대로 볼 때 8주간의 자전거 타기 유산소성 운동은 신체구성, 심폐지구력, 유연성, 근지구력의 통계적으로 유의하게 변화하는 결과를 보였으나 근력에서는 유의함이 나타나지 않았다. 따라서 근력에 긍정적인 효과를 보이는 저항성운동을 포함한 운동프로그램으로 규칙적으로 실시하는 것이 중요한 것으로 판단된다.

Tricalcium phosphate가 치주인대 세포의 성장에 미치는 영향

김해동 경북대학교 대학원 1992 국내석사

치주질환의 진행에 의해 파괴된 치주조직의 재생을 위해 Tricalcium phosphate의 효과를 규명하고자 교정치료를 위해 내원한 3명의 환자로 부터 건강한 제일소구치를 발거하여 치주인대세포를 분리 배양하여, 대조군에는 치주인대세포만을, 실험군에는 치주인대세포에 Tricalcium phosphate를 첨가하여 배양하였다. 배양된 각 세포군에 대해서 세포성장율, 단백질양, ALP활성도를 관찰해본 결과 다음과 같았다. 배양된 각 세포군에 대해서 세포성장율은 치주인대세포만의 대조군에서는 시간 경과에 따라 점차 증가하는 양상을 나타내었으며 TCP를 첨가한 실험군에서는 대조군에 비해 그 정도는 미약하였지만 증가 양상을 보였고, 실험 4일에서 대조군은 실험군에 비해 1.5배 높은 세포수를 나타내었으며 6일과 8일에는 대조군과 거의 버슷한 양상으로 나타나 양군간의 차이는 미미하였으며 전반적으로 세포수는 유의성 있는 증가추이를 나타내었다 (p<0.01). 단백질양을 측정한 실험에서 치주인대세포만을 배양한 대조군과 TCP를 첨가한 실험군에서 시간 경과에 따른 단백질의 양은 증가하였으나 양군간에는 유사하게 나타나 상호간의 유의성은 없었다 (p>0.05). 골기질 형성에 관여하는 효소인 ALP활성도를 10% FBS가 함입된 DMEM에서 4, 8일 동안 배양하여 측정해본 결과 치주인대세포만을 배양한 대조군과 TCP를 첨가한 실험군에서 시간 경과에 따른 ALP활성도는 증가하였으나 양군간에는 유사하게 나타나 상호간의 유의성은 없었다 (p>0.05). This study described the effects of tricalcium phosphate on the growth of cultured human periodontal ligament cells. Periodontal ligament cells for this study were obtained from the healthy periodontal ligament of first premolar teeth of individuals undergoing tooth extraction for orthodontic reasons. In control group, periodontal ligament cells alone were cultured. In experimental group, tricalcium phosphate was added to the periodontal ligament cells. And then each group were characterized by their proliferation rate, protein amount and alkaline phosphatase activity. The results were as follows : In the comparison of the proliferation rate, the control group was slightly higher than the experimental group. At the 4th day, the control group was 1.5-fold higher than the experimental group. At the 6th, 8th day, the rate was similiar with both group. But there was no difference between control group and experimental group at each day. There were statistically significant increased in number of cells in both group. In the protein amount, the control group and the experimental group was similiar at each day. But the protein amount was increased with time sequence. In the alkaline phosphatase activity assay, the experimental group showed similarity with the control group at each time. But there was increased in the ALP activity with time sequence. The results indicate that there is no significant difference between the culture medium contained tricalcium phosphate and pure culture medium.

國際流動性 問題에 관한 硏究

김해동 東亞大學校 大學院 1976 국내석사

Since the Bretton Woods system stepped out, the international liquidity shortages and the unsteady position of dollar as a key currency have been major problems faced by the world economy which has been expanding remarkably. The Bretton Woods system which was based on the so-called gold exchange standard system proved to be unable to solve the international liquidity shortage problems As is well known, there have been so far many arguments on the reform of the International monetary system. Most of the arguments put their emphasis on the possibility of solving the liquidity stortage problem. Also some discussions tried to determine both the role of gold and dollars In the world trade and the involved contradictions. Yet, we do not see from these discussions that any satisfactory answers have been derived so far. To make matters worse, most of the developing countries were opposed to the measures on the international liquidity problems taken by advanced, countries. On the other hand, there arose still strong voices asking to return to gold standard system, while others stood in favor of the free floating exchange system. From a great number of discussions on the reform of the international monetary system derived an intensive system which is called the Kingstern system. The new system seems to find a clue to solve its many contradictions to some degree through the creation of SDK (special drawing rights), increased monetary cooperation among major member countries, and the rearrangement of monetary systems of some major countries. It is really an epoch-making event that the international monetary system, whose problems have been major issues of the world economy since the beginning of the 1960's, finds its way to solve the problems involved. However, taking things coolly, we cannot help but doubt whether the major problems the International monetary system faces can be completely overcome, thus giving a basis for a concrete foundation of the system. It may be possible fro solve the international liquidity shortage problems to some degree through the creation of SDR, the rearrangement of monetary systems of some major countries, and also through the monetary cooperation among some major member countries. However, we worry about the future of the system which basically depends upon the power and the profit of the individual nations. This thesis reviews the major substance of the Bretton Woods system and its problems, and then the discussions concerning the reform of the system, among them the following; (1)gold price policy plan (2)plan to return to gold standard. (3)Triffin plan (4)MCA plan (5) free floating foreign exchange system, and (6) CRU plan etc. These plans for the international monetary reform are reviewed and their implications discussed. From that review, the author draws a conclusion that the very essential problems involved in the international monetary systems are still left unsolved. As Triffin pointed out, the increasing demand for international liquidity may be satisfied either through a continuing supply of SDR, or through a continuing deficit in the balance of payments of the key-currency countries. It cannot be overlooked here that such a situation might not only undermine international confidence in reserve currency but also make the relationship between SDR and gold, gold and dollar very delicate. In the new system, SDR is to be strengthened to supple-neat dollars and pounds. The fundamental problems about the reserve currency cannot be completely solved through SDR. also the creation of SDR may not be enough to fully ease the drain on international liquidity. Along with the creation of SDR; IMF should strengthen the organization which would scientifically manage and operate the paper gold in line with its demand. In the meantime, in the Bretton Woods system, the necessary adjustments in the international balance of payments could not be successfully made. Under the gold standard system, the balance of payments would be automatically controlled by the change of both wage and price which would be determined by inflow and outflow of gold. But in the Bretton Woods system, wage and price were so rigid downward that the balance of payments adjustment mechanism could not operate smoothly. The dollar, which is the national money of the U.S.A, cannot work against the U.S.A permanently. The stability of the national economy of the U.S.A means the shortage of the international liquidity; and the instability of that is the way to the solution of the shortage of the international liquidity. Hence derives the fundamental dilemma, which is never to be solved under the Bretton Woods system. And the international liquidity requirements keeps going up as the gaps in the international balance of payments widen between or among nations. In the Bretton Woods system, the reserve currency available to individual countries was too limited to finance those which had a balance of payments dificit. Therefore, a new positive measure was badly needed in order to adjust the international balance of payments under a new monetary system. In the new system, it is expected that SDR will soften the tight international liquidity. As a conclusion, the creation of SDR may provide the world economy with a new method of easing the current crisis over the international balance of payments, but because of some substantial faults of the SDR it cannot be called a permanent solution to all the problems the international monetary system faces. From the view-point of the long term, the new system is not the perfect equipment but the first step to the betterment of the international monetary system. In future, the most important work of the system is to control and arrange the international liquidity technically. It needs a strong authority to rule and arrange the individual countries which have tendency to seek their national profits.

因果論:中論과 勝論의 比較因果論

김해동 동국대학교 대학원 1961 국내석사

적응적 에너지 분배에 의한 프로그래시브 래디오시티에 관한 연구

김해동 전남대학교 1996 국내석사

컴퓨터 산업이 발전함에 따라 그래픽스의 응용분야도 폭넓게 급성장하고 있다. 그 중에서도 현실감 있는 이미지(photo realistic image) 생성의 필요성이 크게 부각되고 있다. 현실감 있는 이미지를 생성하기 위한 전체 조명 모델(global illumination model)에서 난반사체(diffuse object)들 사이의 조명관계를 가장 잘 설명해 주는 모델이 래디오시티(radiosity)이며, 이는 물체들 사이의 빛 에너지 교환 후에 이루어지는 에너지 평형 상태를 모델링한 것이다. 본 논문에서는 프로그래시브 리파인먼트(progressive refinement) 과정에서 동질의 이미지를 더 빠르게 생성하는 방법을 제시한다. 기존의 방법들은 리시버(receiver)에 분배할 에너지 크기와 무관하게 일정 갯수의 슈팅광선(shooting ray)을 발생하여 처리해 왔으나, 본 논문에서는 프로그래시브 리파인먼트 과정에서 평형상태에 수렴할수록 리시버에 분배할 에너지량이 점점 감소하는 점에 착안하여 에너지량에 따라 슈팅광선의 수를 조절하는 방법을 제안하였다. 따라서, 본 논문에서는 물체들 사이에 주고 받는 에너지 교환량을 미리 예측하는 방법과 그에 따르는 슈팅광선 수를 적응적으로 조정해 줌으로써, 속도를 향상시키는 방법을 제시한다. As computer industry has been developing, the application part of graphics is widly and rapidly growing. Among them, making photo realistic images is very needed. we can make such images by using global illumination models. Among them, the best model that explains the illumination relationship among diffuse objects is radiosity, and it models energy equbrillium state, which is the zero-state of exchanging net energies after exchanging the light energies between sources and receivers. In my thesis, I suggest a method which makes the images of same quality, and I make images faster than the previous methods, vertex radiosity and like that in progressive refinement of radiosity. The previous methods made images by shooting the constant number of ray without the energy size of being distributed to receivers. In progressive refinement course, since the quantity of engergy of being distributed to receivers is getting smaller, according to the fact, I suggest a method which adapts the number of shooting rays as the quantity of distribution enegery. Therefore, in my thesis, I suggest a method which can estimate the exchanged quantity of energy among objects and improve the processing speed as using adapting the number of shooting ray.

Herzberg 동기·위생이론을 활용한 로컬호텔과 체인호텔 종사자의 직무만족도, 이직의도 및 조직몰입에 관한 연구

김해동 경성대학교 2015 국내석사

The purpose of this study was to analyze the Job satisfaction, Turnover Intention and Organization Commitment level of hotel employees using Herzberg's Motivation·Hygiene theory. The survey was conducted between March 2 to 15, 2015. This study used SPSS 20.0 and AMOS 20.0 to conduct frequency analysis, reliability analysis, confirmatory factor analysis, path analysis and chi-square difference test. The result of study, First of all, Herzberg's, theory of hygiene are influenced by satisfaction of employees, organization commitment and turnover intention. By the way, it wasn't effected to factor of motivation properly. Thus, It will be strongly needed to management of compensation, well-organized policy of human resources system. Second, In Hotel business, It showed differences having a strong influence on local and chain hotel according to method of Hotel management. In conclusion, in the hospitality industry, It is desirable that carry out on their own ways of vision and purpose each corporations rather than following regimental rules.

시각장애학생들과 일반학생들의 미디어 이용 실태 : 초등학교 4, 5, 6학년을 대상으로

김해동 세종대학교 교육대학원 2010 국내석사

본 연구는 시각장애학교와 일반초등학교 4, 5, 6학년 학생들의 미디어 (텔레비전, 신문, 라디오, 책, 인터넷) 이용 실태를 비교분석함으로써 시각장애학교 초등부 학생들의 미디어 이용에 필요한 것들이 무엇인지 기초 자료를 제공하는 데 그 목적이 있다. 이를 위하여 첫째, 시각장애초등학생들과 일반초등학생들의 일반적인 미디어 이용 실태를 알아보고 둘째, 시각장애초등학생들과 일반초등학생들의 미디어별 이용 현황을 비교 분석하여 시각장애초등학생들에게 필요한 미디어교육 지원방향을 알아보고자 하였다. 본 연구는 시각장애학교와 일반초등학교에 재학 중인 4, 5, 6학년 학생을 대상으로 진행되었다. 먼저 연구에 참여하기로 동의한 6개 시각장애학교에 설문지를 배부하여 60부 중 51부를 회수하였고 서울, 경기, 충북 지역의 4개 초등학교에 설문지 160부를 배부하여 그 중 113부를 회수 하였다. 설문지는 기초조사 3문항, 일상생활에서 주로 이용하는 미디어에 관한 6문항, 일상생활에서의 텔레비전 시청에 관한 6문항, 일상생활에서의 신문 구독과 관련된 6문항, 일상생활에서의 라디오 청취에 관한 6문항, 일상생활에서의 서적 및 잡지 읽기에 관한 5문항, 일상생활에서의 인터넷사용에 관한 7문항 등 총39문항으로 구성되어 있다. 연구결과 첫째, ‘일주일동안 이용하는 미디어’ 이용 경향은 시각장애초등학생들과 일반초등학생들 모두 인터넷과 텔레비전을 많이 이용하는 것으로 나타났다. 미디어 이용 목적에 따라 시각장애학생들은 서적 및 잡지를 많이 이용하고, 일반초등학생들은 인터넷을 가장 많이 이용하는 것으로 나타났다. 둘째, 시각장애초등학생들이 일반초등학생들에 비해서 텔레비전 시청시간이 적은 것으로 나타났으며 시청 시간대는 일반초등학생들이 시각장애학생들 보다 넓게 나타났다. 두 집단 모두 만화, 드라마 이용률이 높았으나 시각장애초등학생들은 일반초등학생들에 비해 오락, 음악 프로그램 이용률이 낮았다. 셋째, 두 집단 모두 신문을 읽지 않는 것으로 나타났다. 이호희 (1992)의 연구에서도 시각장애 중·고등학생들은 신문을 전혀 읽지 않는 (56.2%)것으로 나타나 시각장애초등학생들과 같은 결과를 보였다. 넷째, 시각장애초등학생들이 일반초등학생들보다 라디오를 많이 청취하는 것으로 나타났다. 시각장애초등학생들은 하루 평균 1시간 이상-2시간 이내 청취 (31.4%), 청취하지 않음 (51.0%)이 다수인 반면에 일반초등학생들은 청취하지 않는 (83.2%) 것으로 나타났다. 다섯째, 시각장애초등학생들은 서적이나 잡지를 볼 때 동화를 주로 읽는 반면 일반초등학생들은 소설을 주로 읽는 것으로 나타났다. 여섯째, 인터넷을 이용 실태를 살펴보면 시각장애초등학생들이 일반초등학생들이 보다 인터넷을 적게 사용하는 것으로 나타났다. 또한 두 집단 모두 인터넷으로 주로 이용하는 컨텐츠는 오락 및 음악이라고 답하였으나 오락을 하는 일반초등학생들의 비율이 시각장애초등학생들보다 더 높은 것으로 나타났다. 시각장애초등학생들은 자료 수집을 위해서도 인터넷을 주로 이용하는 것으로 나타났다. 두 집단 모두 가정에서 인터넷을 주로 이용하였다. 위의 분석결과 일상생활에서의 미디어 이용에 있어서 시각장애초등학생과 일반초등학생은 공통적으로 인터넷과 텔레비전을 주로 이용하고 있었다. 그러나 장애 특성상 시각장애초등학생들은 청각, 촉각을 주로 이용하기 때문에 일반초등학생들보다 서적과 라디오를 더 많이 이용하는 등 조금씩 차이를 보였다. 미디어에 따른 이용실태도 조금씩 차이를 보였는데 텔레비전의 경우 시각장애초등학생들이 일반초등학생들에 비해서 텔레비전 시청시간, 시청 시간대가 적은 것으로 나타났다. 시각장애초등학생들이 텔레비전을 시청할 때 다양한 프로그램을 시청하지 않는 이유와 그에 대한 시각장애초등학생들의 요구사항 등을 조사할 필요가 있다. 두 집단 모두 신문에 대한 관심을 가지도록 할 필요가 있었는데 특히 시각장애초등학생들에게도 점자신문 등의 제공을 통하여 신문을 통해서 세상을 살펴볼 수 있는 길을 열어주어야 할 것으로 보인다. 또한 시각장애초등학생들은 인터넷을 여가와 정보수집에 적절히 이용하고 있음을 알 수 있었는데 이메일, 메신저 등의 이용 비율은 낮게 나타나 인터넷을 통하여 다른 사람과 소통할 수 있는 다양한 방법에 대하여 교육을 실시할 필요가 있다고 하겠다. 이 밖에도 후속 연구에서는 개방형 질문을 통해 사용 안하는 이유 등에 대한 정보를 포함해도 좋을 것이다. This study aims to provide basic data for them after examining what elementary school students with sight disabilities need when using media(television, newspaper, radio, book and internet) by comparing and analyzing media use of students with sight disabilities and normal students in fourth, fifth and sixth grade of elementary school. To achieve this research purpose, first of all, general media use of students with sight disabilities and normal students were examined and secondly, support methods for media education required for students, who are blind were investigated by comparing and analyzing media use of students with sight disabilities and normal students. This study was conducted with students that are in fourth, fifth and sixth grade of special schools for blind people and normal schools. First of all, 60 questionnaires were delivered to 6 special schools for blind people that cooperated with this study and then, 50 papers of them were collected. Also, after delivering 160 papers to 4 normal schools based on Seoul, Gyung-ki and Choong-buk provinces, 113 of them were collected. The questionnaires consisted of total 39 questions; three questions about basic survey, six questions about media they mainly use, six questions about watching television in daily life, six questions related to reading newspapers in daily life, six questions regarding listening to radio in daily life, five questions about reading books or magazines in daily life and seven questions about internet utilization in daily life. As a result, firstly, in use tendency of 'media that they use for a week', both of students with sight disabilities and normal students used internet and television a lot. Students, who are blind, mainly used books or magazines and normal students mainly used internet according to their use purposes of media. Second, students, who are visually impaired, less watched television than normal students and their watching time of normal students was broader than handicapped students. Also, use rate in cartoon and drama was high in both groups, but students with sight disabilities less used entertaining and music programs than normal students. Third, neither of groups red newspapers. According to the research by Lee, Ho-hee(1992), it was found that majority of middle and high school students with sight disabilities don't read newspapers (56.2%) and such result is equal to this study's result. Fourth, students with sight disabilities listened to radio more than normal students. While many of them answered that they listen to radio for over 1 hour~less than 2 hours a day in average (31.4%) or don't listen to it (51.0%), majority of non-handicapped students responded that they don't listen to it (83.2%). Fifth, students with sight disabilities mainly red fairy tales when reading books or magazines, but normal students red novels mainly. Sixth, students, who are blind less used internet than normal students. Also, both groups responded that they mainly use entertaining or music contents, but rate of normal students, who use entertaining contents was higher than blind students. Also, blind students used internet to find data. Both groups used internet mainly at their houses. According to analysis of the results as above, students with sight disabilities and normal students commonly used internet and television a lot. However, blind students used their hearing and touch when using media, due to disability's property. So they used books and radio more than normal students. There was a significant difference in use of media. For television, students with sight disabilities less watched TV than normal students. Therefore, studies on reasons, why blind students don't watch a variety of programs when watching TV and their requirements would be required in future. In this research, more concerns about newspaper were needed in both groups. Especially, it was judged that we need to develop system for blind students to view the world through a braille newspaper. Also, students with sight disabilities properly used internet for their leisure lives and collecting data, but they less used e-mail or messengers. So education for a diversity of methods to communicate with others through the internet would be required. In addition, future studies need to include the reasons, why they don't prefer using internet through an open question.