일본 서비스 업체 2개사의 고정고객 관리에 대한 탐색

고무라아유코 ( Komura Ayuko ),호소다마사히로 ( Hosoda Masahiro ) 한국유통경영학회(구 한국유통정보학회) 2017 유통경영학회지 Vol.20 No.4

This study explores ways to define fixed customers, identify the benefits earned from them, and develop relationships with them. We conducted a case study at a mail-order company and a department store. Data were collected through structured questionnaire-based interviews and analyzed by applying the KJ (Kawakita Jiro) method to categorize how interview respondents defined fixed customers, assessed their financial contribution, and managed relationships with them. The results show, first, that both companies use the total number of transactions, amount spent per transaction, purchases of core products, and the variety of products purchased by their customers to define fixed customers. Second, both companies consider sales stability to be the primary financial benefit of fixed customers. Third, both companies run a loyalty program to develop long-term relationships with fixed customers and gain financial benefits. Our study contributes to the literature in several ways. First, it suggests that the number of transactions may be amore useful classification standard than the amount spent per transaction. Second, we argue that the stability emanating from trade with fixed customers increases the forecasting accuracy of shipment numbers.

From Radon and Thoron Measurements, Inhalation Dose Assessment to National Regulation and Radon Action Plan in Cameroon

Saïdou,Shinji Tokonami,Masahiro Hosoda,Augustin Simo,Joseph Victor Hell,Olga German,Esmel Gislere Oscar Meless 대한방사선방어학회 2022 방사선방어학회지 Vol.47 No.4

Background : The current study reports measurements of activity concentrations of radon (222Rn) and thoron (220Rn) in dwellings , followed by inhalation dose assessment of the public , and then by the development of regulation and the national radon action plan (NRAP) in Cameroon . Materials and Methods : Radon , thoron , and thoron progeny measurements were carried out from 2014 to 2017 using radon-thoron discriminative detectors (commercially RADUET) in 450 dwellings and thoron progeny monitors in 350 dwellings . From 2019 to 2020 , radon track detectors (commercially RADTRAK) were deployed in 1 , 400 dwellings . It was found that activ- ity concentrations of radon range in 1 , 850 houses from 10 to 2 , 620 Bq/m3 with a geometric mean of 76 Bq/m3 . Results and Discussion : Activity concentrations of thoron range from 20 to 700 Bq/m3 with a geometric mean of 107 Bq/m3 . Thoron equilibrium factor ranges from 0 . 01 to 0 . 6 , with an arithmetic mean of 0 . 09 that is higher than the default value of 0 . 02 given by UNSCEAR . On average , 49% , 9% , and 2% of all surveyed houses have radon concentrations above 100 , 200 , and 300 Bq/m3 , respectively. The average contribution of thoron to the inhalation dose due to radon and thoron exposure is about 40% . Thus , thoron cannot be neglected in dose assessment to avoid biased results in radio-epidemiological studies . Only radon was considered in the drafted regulation and in the NRAP adopted in October 2020 . Reference levels of 300 Bq/m3 and 1 , 000 Bq/m3 were recommended for dwellings and workplaces . Conclusion : Priority actions for the coming years include the following : radon risk mapping , promotion of a protection policy against radon in buildings , integration of the radon prevention and mitigation into the training of construction specialists , mitigation of dwellings and workplaces with high radon levels , increased public awareness of the health risks associated with radon , and development of programs on the scientific and technical aspects .

일본 기수호 (Lake Obuchi)에서 생태계 모델의 개발과 적용

( Ueda Shinji ),( Kunio Kondo ),( Jiro Inaba ),( Masahiro Hosoda ),( Hiroshi Kutsukake ),( Yasushi Seike ),( Kisaburo Nakata ) 한국하천호수학회 2004 생태와 환경 Vol.37 No.4

In order to evaluate the water quality (N, P and C) and the biological mass balance of semi-enclosed brackish Lake Obuchi, Japan, an ecosystem model was developed and applied to the lake, using the flow field calculated by a hydrodynamic model. The time series data of the observed tide level, river discharge and meteorological parameters from January 2001 to December 2002 were incorporated as the parameters of the hydrodynamic model. Water quality and biomass balance were estimated by the ecosystem model, and simulated fluctuations in water quality agreed with our observations. The carbon contents of POC, phytoplankton and zooplankton in the lake were calculated by the model at an average 7200, 1500 and 22 ㎏, respectively, which somewhat agreed with our observations of POC (5900 ㎏), phytoplankton (3800 ㎏), and zooplankton (150 ㎏).

Development and Application of the Ecosystem Model in Brackish Lake Obuchi, Japan

Ueda, Shinji,Kunio Kondo,Jiro Inaba,Masahiro Hosoda,Hiroshi Kutsukake,Yasushi Seike,Kisaburo Nakata 한국수생태학회(구 한국하천호수학회) 2004 생태와 환경 Vol.37 No.4

Comparative analysis of radon, thoron and thoron progeny concentration measurements

Janik, Miroslaw,Tokonami, Shinji,Kranrod, Chutima,Sorimachi, Atsuyuki,Ishikawa, Tetsuo,Hosoda, Masahiro,Mclaughlin, James,Chang, Byung-Uck,Kim, Yong Jae Oxford University Press 2013 Journal of radiation research Vol.54 No.4

<P>This study examined correlations between radon, thoron and thoron progeny concentrations based on surveys conducted in several different countries. For this purpose, passive detectors developed or modified by the National Institute of Radiological Sciences (NIRS) were used. Radon and thoron concentrations were measured using passive discriminative radon-thoron detectors. Thoron progeny measurements were conducted using the NIRS-modified detector, originally developed by Zhuo and Iida. Weak correlations were found between radon and thoron as well as between thoron and thoron progeny. The statistical evaluation showed that attention should be paid to the thoron equilibrium factor for calculation of thoron progeny concentrations based on thoron measurements. In addition, this evaluation indicated that radon, thoron and thoron progeny were independent parameters, so it would be difficult to estimate the concentration of one from those of the others.</P>

Reduction of Outdoor and Indoor Ambient Dose Equivalent after Decontamination in the Fukushima Evacuation Zones

Yoshida-Ohuchi, Hiroko,Kanagami, Takashi,Naitoh, Yutaka,Kameyama, Mizuki,Hosoda, Masahiro The Korean Association for Radiation Protection 2017 방사선방어학회지 Vol.42 No.1

Background: One of the most urgent issues following the accident at the Fukushima Daiichi nuclear power plant (FDNPP) was the remediation of the land, in particular, for residential area contaminated by the radioactive materials discharged. In this study, the effect of decontamination on reduction of ambient dose equivalent outdoors and indoors was evaluated. The latter is essential for residents as most individuals spend a large portion of their time indoors. Materials and Methods: From December 2012 to November 2014, thirty-seven Japanese single-family detached wooden houses were investigated before and after decontamination in evacuation zones. Outdoor and indoor dose measurements (n = 84 and 114, respectively) were collected based on in situ measurements using the NaI (Tl) scintillation surveymeter. Results and Discussion: The outdoor ambient dose equivalents [$H^*(10)_{out}$] ranged from 0.61 to $3.71{\mu}Sv\;h^{-1}$ and from 0.23 to $1.32{\mu}Sv\;h^{-1}$ before and after decontamination, respectively. The indoor ambient dose equivalents [$H^*(10)_{in}$] ranged from 0.29 to $2.53{\mu}Sv\;h^{-1}$ and from 0.16 to $1.22{\mu}Sv\;h^{-1}$ before and after decontamination, respectively. The values of reduction efficiency (RE), defined as the ratio by which the radiation dose has been reduced via decontamination, were evaluated as $0.47{\pm}0.13$, $0.51{\pm}0.13$, and $0.58{\pm}0.08$ ($average{\pm}{\sigma}$) when $H^*(10)_{out}$ < $1.0{\mu}Sv\;h^{-1}$, $1.0{\mu}Sv\;h^{-1}$ < $H^*(10)_{out}$ < $2.0{\mu}Sv\;h^{-1}$, and $2.0{\mu}Sv\;h^{-1}$ < $H^*(10)_{out}$, respectively, indicating the values of RE increased as $H^*(10)_{out}$ increased. It was found that the values of RE were $0.53{\pm}0.12$ outdoors and $0.41{\pm}0.09$ indoors, respectively, indicating RE was larger outdoors than indoors. Conclusion: Indoor dose is essential as most individuals spend a large portion of their time indoors. The difference between outdoors and indoors should be considered carefully in order to estimate residents' exposure dose before their returning home.

Public Exposure to Natural Radiation and the Associated Increased Risk of Lung Cancer in the Betare-Oya Gold Mining Areas, Eastern Cameroon

Nkoulou II Joseph Emmanuel Ndjana,Engola Louis Ngoa,Dallou Guy Blanchard,Saïdou,Bongue Daniel,Hosoda Masahiro,Njock Moïse Godefroy Kwato,Tokonami Shinji 대한방사선방어학회 2023 방사선방어학회지 Vol.48 No.2

Background : This study aims to reevaluate natural radiation exposure , following up on our previous study conducted in 2019 , and to assess the associated risk of lung cancer to the public residing in the gold mining areas of Betare-Oya , east Cameroon , and its vicinity. Materials and Methods : Gamma-ray spectra collected using a 7 . 62 cm × 7 . 62 cm in NaI(Tl) scintillation spectrometer during a car-borne survey, in situ measurements and laboratory mea- surements performed in previous studies were used to determine the outdoor absorbed dose rate in air to evaluate the annual external dose inhaled by the public . For determining internal exposure , radon gas concentrations were measured and used to estimate the inhalation dose while considering the inhalation of radon and its decay products . Results and Discussion : The mean value of the laboratory-measured outdoor gamma dose rate was 47 nGy/hr, which agrees with our previous results (44 nGy/hr) recorded through direct mea- surements (in situ and car-borne survey) . The resulting annual external dose (0 . 29 ± 0 . 09 mSv/yr) obtained is similar to that of the previous study (0 . 33 ± 0 . 03 mSv/yr) . The total inhalation dose resulting from radon isotopes and their decay products ranged between 1 . 96 and 9 . 63 mSv/yr with an arithmetic mean of 3 . 95 ± 1 . 65 mSv/yr. The resulting excess lung cancer risk was esti- mated ; it ranged from 62 to 216 excess deaths per million persons per year (MPY) , 81 to 243 ex- cess deaths per MPY, or 135 excess deaths per MPY, based on whether risk factors reported by the U. S . Environmental Protection Agency, United Nations Scientific Committee on the effects of Atomic Radiation , or International Commission on Radiological Protection were used , re- spectively. These values are more than double the world average values reported by the same agencies . Conclusion : There is an elevated level of risk of lung cancer from indoor radon in locations close to the Betare-Oya gold mining region in east Cameroon . Therefore , educating the public on the harmful effects of radon exposure and considering some remedial actions for protection against radon and its progenies is necessary.