멀티미디어 전송을 위한 무선가입자용 RF-모듈의 설계 및 제작

김상태,신철재,Kim, Sang-Tae,Shin, Chull-Chai 한국전기전자학회 1999 전기전자학회논문지 Vol.3 No.2

본 논문에서는 W-CDMA 이용한 10 [MHz]의 채널 대역폭을 갖는 다중채널 무선가입자망 단말기용 RF-모듈을 설계 제작하였다. RF-모듈은 송수신전단, 주파수합성기, 변복조기 및 전력제어회로로 구성하였다. 제작한 RF-모듈에 대한 시험결과 송신전력은 250 [mW], 통과대역내의 진폭과 위상왜곡을 측정한 전력의 평탄도는 ${\pm}1.5[dB]$를 얻었다. 또한 송신시 확산신호의 Chip Rate는 8.312 [Mcps]를 얻었고, 주파수합성기에 대한 측정결과는 RF 대역과 변복조를 위한 국부발진신호 주파수는 설계규격을 만족하였다. 수신전계강도특성과 AGC의 동작범위는 모두 60 [dB]로 만족하였고, RF-모듈과 기저대역과의 연동여부를 확인하기 위해 페이저도와 눈패턴을 측정한 결과 좋은 결과를 얻었다. In this paper, the RF-modules composed of front-end, frequency synthesizer, modulator/demodulator and power control multi channel WLL personal system for W-CDMA using 10 [MHz] RF channel bandwidth has been implemented and considered. The measured transmission power is 250 [mW] which is very close to the required value. The measured flatness of power at the final output stage is ${\pm}1.5[dB]$ over the required bandwidth of the receiver. In addition, it is found that the chip rate transmitting spread signal is set to 8.192 [MHz], the required rate. The frequencies of RF_LO signal and LO signal of the modulator and the demodulator measured by a frequency synthesizer are satisfied with design requirements. The operating range of the receiving strength signal indicator and AGC units shows 60 [dB] respectively. Also the measured phasor diagram and eye pattern for deciding the RF modules compatible with baseband digital signal processing part are shown good results.

피로수명예측을 위한 잔류강도 저하모델의 파라미터 결정법 제안(II)

김상태,장성수,Kim, Sang-Tae,Jang, Seong-Su 대한기계학회 2001 大韓機械學會論文集A Vol.25 No.9

A new method of parameter determination in the fatigue residual strength degradation model is proposed. The new method and minimization technique is compared experimentally to account for the effect of tension-compression fatigue loading of spheroidal graphite cast iron and graphite/epoxy laminate. It is shown that the correlation between the experimental results and the theoretical prediction on the fatigue life and residual strength distribution using the proposed method is very reasonable. Therefore, the proposed method is more adjustable in the determination of the parameter than minimization technique for the prediction of the fatigue characteristics.

의학상식-아픔'만성통증'의 정체

김상태,Kim, Sang-Tae 한국건강관리협회 1985 건강소식 Vol.9 No.11

의학상식-스트레스와 정신건강

김상태,Kim, Sang-Tae 한국건강관리협회 1985 건강소식 Vol.9 No.12

의학상식-임신 구토와 입덧

김상태,Kim, Sang-Tae 한국건강관리협회 1986 건강소식 Vol.10 No.2

직장인의 건강관리-직장인의 스트레스와 정신장애

김상태,Kim, Sang-Tae 한국건강관리협회 1987 건강소식 Vol.11 No.1

직장인의 스트레스와 나아가 이로 인한 정신장애의 극복책은 우선적으로 스트레스의 바른 해소책 개발과 인격적 취약성의 자각 및 인격 성숙을 위한 부단한 노력 이다.

위험한 두통과 위험하지 않은 두통

김상태,Kim, Sang-Tae 한국건강관리협회 1987 건강소식 Vol.11 No.4

두통이 매우 흔한 이유로는 아마도 두개골내의 귀중한 뇌조직을 보호하기 위해서 말단 통각수용기가 안면과 두피에 신체의 다른 부위에서 보다 더 풍부하게 분포되어 있고, 눈, 코, 입같은 고도로 민감한 조직들이 두부에 있어 보호의 필요가 있고, 또 지적인 사람의 두부는 뇌가 있는 곳이므로 신체의 다른 어느 부위에서 보다 더 관심이 대상이 되는 구조이기 때문이다.

Arbutin , Glycolic Acid , Kojic Acid 및 Pentadecenoic Acid가 in vitro 및 in vivo에서 UVB 조사에 의한 색소형성에 미치는 영향

김상태,서기석,채영수,엄상철 ( Sang Tae Kim,Kee Suck Suh,Young Soo Chae,Sang Cheul Eom ) 대한피부과학회 1994 대한피부과학회지 Vol.32 No.6

Background:Melanin pigmentation palys a major role in normal skin color. The rates of melanin synthesis by melanocytes appear to be regulated by ultraviolet-B UVB) rediation and chemicals, though the precise mechanisms modulating human epidermal pigmentation are unknown. Several chemicals including arbutin, kojic acid(KA), pentadecen?ic acid(PDA) and glycolic acid(GA) have been suggested as a melanogenesis inhibitory compounds because of their chemical or biological similarities with hydroquinone or their tyrosinase inhibitory effcet. Objective:The purpose of this study was to evaluate the inhibitory effect of arbutin, GA, KA and PDA on UV-induced melanogenesis in the in vitro and in vivo pigmentary system. Methods:Cultured normal melanocytes and B-16 melanoma cells, and C57BL mice and human volunteers were used for in vitro and in vivo studies respectively. They were administered to UVB irradiated or nonirradiated cultured normal human melanocytes, and B-16 melanoma cells. For the in vivo study, these chemicals were topically applied to C57BL mice and human ?olunteer skin after UVB irradiation. Numeric and morphologic changes and melanin content were measured in cultured normal human melanocytes and B-16 melanoma cells. In the C57BL mice, numeric and morphologic changes of split-DOPA stained melanocytes were assessed. In the human volunt?rs, gross pigementary changes wre evaluated. Results 1. The number and melanin content of cultured melanocytes initially decreased after UVB-irradiation, but the melanin content increased 5 days after irradiation. 2. Cell numbers of irradiated or nonirradiated cultured human melanocytes decreased in arbutin(10^-3M), KA(10^-3M, 10^-5M), PDA(10^-3M) groups. Those of the cultured B-16 mealnoma cells decreased only in the arbutin(10^-3M) group after UVB irradiation. 3. Melanin contents of cultured human melanocytes decreased in crbutin(10^-3M, 10^-5M), KA(10^-3M, 10^-5M) and PDA(10^-3M) groups. Those of cultured B-16 melanon a cells decreased in arbutin(10^-3M, 10^-5M) groups after UVB-irradiation or nonirradiation. 4. The number of split-DOPA(+) melanocytes decreased in the groups ?reated with KA 1% for 3,5 and 7 weeks, KA 0.1%, arbutin 3%, arbutin 5% for 5and 7 qwwks and PDA 5.0% for 7 weeks in the C57BL mice. 5. The number of split-DOPA(+) melanocytes decreased in the groups ?reated with KA 1.0%, PDA 5.0%, arbutin 3% and arbutin 5% for 5 and 7 weeks and KA 0.1% for 7 weeks in UVB irradiated C57BL mice. 6. Visible inhibition of UVB-induced hyperpigmentation was observed in arbutin applied sites in 4 of the 6 volunteers 3 weeks after the application. GA did not show an inhibitory effect on UVB-induced hyperpigmentation in all subjects. Conclusion:Arbutin, KA, PDA had a suppressive effect on ? of nonirradiated melanocytes and melanoma cells as well as UVB-induced hyperpigmentation. It is suggested that these drugs might be candidates as compounds that may control hyperpigmentary disorders.(Kor J Dermatol 1994;32(6):977~989)

흰쥐 정소세포에서의 Cadmium 독성 작용과 Selenium 전처리의 영향

김상태,부문종,최임순 ( Sang Tae Kim,Moon Jong Boo,Rim Soon Choe ) 한국환경생물학회 1990 환경생물 : 환경생물학회지 Vol.8 No.1

To investigate the cadmium toxicity to testis and the effect of selenium pretreatment, male rats were subcutaneously injected with Cd and/or Se prior to Cd. In doing so, the respiration rates of mitochondria, the lysosomal activities of acid phosphatase and the cellular levels of GSH were measured. Also, the testicular ultrastructures were observed. Cd only-treated group showed that the respiration rates of mitochondria, the lysosomal activities of acid phosphatase and the level of GSH were reduced on the whole. In contrast to above group, Se-pretreated group appeared to be recovered: the respiration rate was restored more than that of control group and the enzyme activity was restored somewhat, however less than that of the control group. The level of GSH was recovered to the level of control group in Se-pretreated group. According to ultrastructural studies, Cd-treated group showed the swelling and destruction of mitochondria and the production of lipid droplets. In contrast, Se-pretreated group appeared not to be different from control group. So, all of these results would indicate that Se has a protective function against Cd toxicity in the rat testis.

감은사의 사리장엄에 의한 2탑구성원리에 관한 연구

김상태,Kim, Sang-Tae 한국건축역사학회 2007 건축역사연구 Vol.16 No.2

The purpose of this article is making investigation of the principal composition of the twin-pagodas in Buddhist temple through ornaments of a case preserving relics of Buddha in the east and west pagodas of Gameunsa temple. This research has an important meaning in clarifying that the concept of placement two Buddhas together with lotus sutra, which was only applied to Bulkuksa temple, has been extended to Gameunsa temple. And this observation gave us a clear explanation for the principal composition at the twin-pagodas in Buddhist temple plans. The author obtained the following conclusion from this article : The cases preserving relics of the Buddha for the west and east pagodas are globally in similar form as the type of a royal palace. But the different points between eastern and western can be seen on the existence of Buddhist statues on the base floor, set-up of the gate at railings, and 4 lion statues at a coner of the base floor. In the western pagoda, there are Buddha statues above the base-floor of the cases preserving relics. These Buddha statues are composed of a boy monks and angels with playing music for the praise of the Sakyamuni Buddha lecturing the Lotus sutra at YoungChui Mountain. On the other hand, in the eastern pagoda, Buddha statues on the cases preserving relics are composed of a the Four Devas and monks as a defending God of the nation of Buddha. In the eastern pagoda, one can see something that does not exist in the western pagoda, which is a gate located in railing of a case preserving the relics. This gate described the scene of the Sakyamuni Buddha entering into the pagoda of 7 treasures. In a corner of the case preserving relics in the eastern pagoda, there is another thing which does not exist in the western pagoda. This is a sculpture of a lion which symbols the seat of Lion supporting the Buddha in the Dabotap(the pagoda of 7 treasures). When we observe the form and structure, the descriptions at the railings, the gate, the shrine, the statue of a lion, and the accessories in jewelries, at the cases preserving the relics in the eastern pagoda, one can realize that they have the same combination structures between the ones at Dabotaps in Bulguksa temple and those in China as well as in Japan, all of which represent the Gyun-Bo-Tap-Pum of Lotus Sutra. Among the distribution rules in the twin-pagodas in Buddhist temple, the application of the ideal of lotus was known to be effected only to Bulguksa temple. But from the result of the present article, it is more clearly proved by applying the Gameunsa temple that the distribution theory in the twin-pagodas in Buddhist temple was in fact based on the ideal of lotus.